sock_pattern_generator.sh

#!/bin/sh
#
# Knitting Pattern Generator for Basic Socks
# POSIX-compliant script for generating custom knitting patterns
#

# Set strict mode for better error handling
set -e

# Color codes (will check if terminal supports colors)
if [ -t 1 ]; then
    BOLD='\033[1m'
    RESET='\033[0m'
    HIGHLIGHT='\033[1;32m'
else
    BOLD=''
    RESET=''
    HIGHLIGHT=''
fi

# ============================================================================
# UTILITY FUNCTIONS
# ============================================================================

clear_screen() {
    clear
}

print_header() {
    clear_screen
    printf "%b=== BASIC SOCK PATTERN GENERATOR ===%b\n\n" "$BOLD" "$RESET"
}

print_section() {
    printf "\n%b>>> %s%b\n" "$HIGHLIGHT" "$1" "$RESET"
}

pause_for_user() {
    printf "\nPress Enter to continue..."
    read -r dummy
}

printf_wrapped() {
    # Prints text with 80-character line wrapping
    printf "%b" "$@" | fold -w 80 -s
}

print_welcome() {
    printf "%b" "============================================\n${HIGHLIGHT}WELCOME TO THE BASIC SOCK PATTERN GENERATOR!${RESET}\n============================================\n\nThis tool will help you create a basic sock knitting pattern based on your measurements, gauge, and design preferences. Follow the prompts to input your information, review the generated pattern, and make any adjustments you'd like before finalizing it.\n\n${BOLD}NOTE: You must knit a gauge swatch in the round before using this tool to ensure accurate stitch counts.${RESET}\n\nNOTE: This tool is for hand-knit socks - if you are looking for machine-knit sock patterns, please check out the resources linked in the README.\n\n${HIGHLIGHT}Let's get started!${RESET}\n" | fold -w 80 -s
}


# ============================================================================
# INPUT FUNCTIONS
# ============================================================================

get_construction_method() {
    print_section "Sock Construction Method"

    printf "How do you want to knit your socks?\n"
    printf "1) Cuff-Down (start at cuff, knit towards toe)\n"
    printf "2) Toe-Up (start at toe, knit towards cuff)\n"
    printf "\nChoice (1-2): "
    read -r method_choice

    case "$method_choice" in
        1)
            CONSTRUCTION_METHOD="cuff-down"
            ;;
        2)
            CONSTRUCTION_METHOD="toe-up"
            ;;
        *)
            CONSTRUCTION_METHOD="cuff-down"
            ;;
    esac
}

get_measurement_units() {
    print_section "Measurement Units"

    printf "Which measurement system do you prefer?\n"
    printf "1) Imperial (inches)\n"
    printf "2) Metric (centimeters)\n"
    printf "\nChoice (1-2): "
    read -r unit_choice

    case "$unit_choice" in
        1)
            MEASUREMENT_UNITS="imperial"
            UNIT_LENGTH="inches"
            UNIT_DISTANCE="yards"
            ;;
        2)
            MEASUREMENT_UNITS="metric"
            UNIT_LENGTH="cm"
            UNIT_DISTANCE="meters"
            ;;
        *)
            MEASUREMENT_UNITS="imperial"
            UNIT_LENGTH="inches"
            UNIT_DISTANCE="yards"
            ;;
    esac
}

# Conversion helper: cm to inches
cm_to_inches() {
    printf "%.1f" "$1" | awk '{printf "%.1f", $1 / 2.54}'
}

# Conversion helper: inches to cm
inches_to_cm() {
    printf "%.1f" "$1" | awk '{printf "%.1f", $1 * 2.54}'
}

get_foot_size() {
    print_section "Foot Size Selection"

    printf "Choose foot size input method:\n"
    printf "1) US Women's Shoe Size\n"
    printf "2) US Men's Shoe Size\n"
    printf "3) Enter foot dimensions\n"
    printf "\nChoice (1-3): "
    read -r size_method

    case "$size_method" in
        1)
            printf "\nUS Women's Shoe Size (5-13): "
            read -r size
            SHOE_SIZE="$size"
            SHOE_SIZE_TYPE="Women's"
            compute_foot_length_from_womens_size "$size"
            ;;
        2)
            printf "\nUS Men's Shoe Size (5-16): "
            read -r size
            SHOE_SIZE="$size"
            SHOE_SIZE_TYPE="Men's"
            compute_foot_length_from_mens_size "$size"
            ;;
        3)
            SHOE_SIZE=""
            SHOE_SIZE_TYPE=""
            if [ "$MEASUREMENT_UNITS" = "metric" ]; then
                printf "\nFoot length (cm): "
            else
                printf "\nFoot length (inches): "
            fi
            read -r input_length
            if [ "$MEASUREMENT_UNITS" = "metric" ]; then
                FOOT_LENGTH=$(cm_to_inches "$input_length")
            else
                FOOT_LENGTH="$input_length"
            fi

            if [ "$MEASUREMENT_UNITS" = "metric" ]; then
                printf "Foot circumference (cm): "
            else
                printf "Foot circumference (inches): "
            fi
            read -r input_circumference
            if [ "$MEASUREMENT_UNITS" = "metric" ]; then
                FOOT_CIRCUMFERENCE=$(cm_to_inches "$input_circumference")
            else
                FOOT_CIRCUMFERENCE="$input_circumference"
            fi
            ;;
        *)
            printf "Invalid choice. Using default size 8.\n"
            FOOT_LENGTH=9.5
            FOOT_CIRCUMFERENCE=8
            SHOE_SIZE=""
            SHOE_SIZE_TYPE=""
            ;;
    esac
}

compute_foot_length_from_womens_size() {
    # Approximate conversion: Women's size to foot length in inches
    # Formula: ((US Size + 21) / 3) * 0.9 for 90% (negative ease for proper fit)
    size=$1
    FOOT_LENGTH=$(printf "%.1f" "$size" | awk '{printf "%.1f", (($1 + 21) / 3) * 0.9}')
    FOOT_CIRCUMFERENCE=$(printf "%.1f" "$size" | awk '{printf "%.1f", 7.5 + ($1 * 0.08)}')
}

compute_foot_length_from_mens_size() {
    # Approximate conversion: Men's size to foot length in inches
    # Formula: ((US Size + 22) / 3) * 0.9 for 90% (negative ease for proper fit)
    size=$1
    FOOT_LENGTH=$(printf "%.1f" "$size" | awk '{printf "%.1f", (($1 + 22) / 3) * 0.9}')
    FOOT_CIRCUMFERENCE=$(printf "%.1f" "$size" | awk '{printf "%.1f", 8.0 + ($1 * 0.08)}')
}

get_gauge() {
    print_section "Gauge Information"

    printf "How do you want to enter gauge?\n"
    printf "1) Stitches/rows per inch (standard)\n"
    printf "2) Stitches/rows per 4 inches (common for swatches)\n"
    printf "3) Stitches/rows over custom number of inches\n"
    printf "4) Stitches/rows per 10 cm (metric swatch)\n"
    printf "5) Stitches/rows over custom number of cm\n"
    printf "Choice (1-5): "
    read -r gauge_method

    case "$gauge_method" in
        1)
            printf "\nStitches per inch: "
            read -r GAUGE_SPI
            GAUGE_WIDTH=1
            printf "Rows per inch: "
            read -r GAUGE_RPI
            GAUGE_HEIGHT=1
            ;;
        2)
            printf "\nStitches per 4 inches: "
            read -r GAUGE_SPI
            GAUGE_WIDTH=4
            printf "Rows per 4 inches: "
            read -r GAUGE_RPI
            GAUGE_HEIGHT=4
            ;;
        3)
            printf "\nHow many stitches over your measurement? "
            read -r GAUGE_SPI
            printf "How many inches was your measurement? "
            read -r GAUGE_WIDTH
            printf "How many rows over how your measurement? "
            read -r GAUGE_RPI
            printf "How many inches was your measurement? "
            read -r GAUGE_HEIGHT
            ;;
        4) 
            printf "\nStitches per 10 cm: "
            read -r GAUGE_SPI
            GAUGE_WIDTH=3.93701 # 10 cm in inches
            printf "Rows per 10 cm: "
            read -r GAUGE_RPI
            GAUGE_HEIGHT=3.93701
            ;;
        5)
            printf "\nHow many stitches over your measurement? "
            read -r GAUGE_SPI
            printf "How many cm was your measurement? "
            read -r GAUGE_WIDTH_CM
            GAUGE_WIDTH=$(cm_to_inches "$GAUGE_WIDTH_CM")
            printf "How many rows over how your measurement? "
            read -r GAUGE_RPI
            printf "How many cm was your measurement? "
            read -r GAUGE_HEIGHT_CM
            GAUGE_HEIGHT=$(cm_to_inches "$GAUGE_HEIGHT_CM")
            ;;
        *)
            printf "Invalid choice. Using 7 SPI, 10 RPI.\n"
            GAUGE_SPI=7
            GAUGE_WIDTH=1
            GAUGE_RPI=10
            GAUGE_HEIGHT=1
            ;;
    esac
}

get_leg_pattern() {
    print_section "Leg Pattern Choice"

    printf "Choose leg pattern:\n"
    printf "1) Stockinette\n"
    printf "2) Ribbing\n"
    printf "Choice (1-2): "
    read -r leg_choice

    case "$leg_choice" in
        1)
            LEG_PATTERN="stockinette"
            LEG_PATTERN_NOTES="Knit all rounds (stockinette stitch)"
            ;;
        2)
            LEG_PATTERN="ribbing"
            printf "\nLeg ribbing pattern:\n"
            printf "1) 1x1 Ribs (K1, P1)\n"
            printf "2) 2x2 Ribs (K2, P2)\n"
            printf "Choice (1-2): "
            read -r rib_choice
            case "$rib_choice" in
                1)
                    LEG_PATTERN="1x1 ribbing"
                    LEG_PATTERN_NOTES="K1, P1 throughout"
                    ;;
                2)
                    LEG_PATTERN="2x2 ribbing"
                    LEG_PATTERN_NOTES="K2, P2 throughout"
                    ;;
                *)
                    LEG_PATTERN="1x1 ribbing"
                    LEG_PATTERN_NOTES="K1, P1 throughout"
                    ;;
            esac
            ;;
        *)
            LEG_PATTERN="stockinette"
            LEG_PATTERN_NOTES="Knit all rounds (stockinette stitch)"
            ;;
    esac
}

get_cuff_pattern() {
    print_section "Cuff Pattern Choice"

    printf "Choose cuff ribbing pattern:\n"
    printf "1) 1x1 Ribs (K1, P1)\n"
    printf "2) 2x2 Ribs (K2, P2)\n"
    printf "Choice (1-2): "
    read -r cuff_rib_choice

    case "$cuff_rib_choice" in
        1)
            CUFF_PATTERN="1x1 ribbing"
            CUFF_PATTERN_NOTES="K1, P1 throughout"
            ;;
        2)
            CUFF_PATTERN="2x2 ribbing"
            CUFF_PATTERN_NOTES="K2, P2 throughout"
            ;;
        *)
            CUFF_PATTERN="1x1 ribbing"
            CUFF_PATTERN_NOTES="K1, P1 throughout"
            ;;
    esac
}

get_toe_type() {
    print_section "Toe Type Selection"

    if [ "$CONSTRUCTION_METHOD" = "toe-up" ]; then
        printf "Choose toe construction (Toe-Up):\n"
        printf "1) Short Row Toe (wrapped stitches)\n"
        printf "2) Wedge Toe (increases on sides)\n"
        printf "Choice (1-2): "
        read -r toe_choice

        case "$toe_choice" in
            1)
                TOE_TYPE="short row"
                ;;
            2)
                TOE_TYPE="wedge"
                ;;
            *)
                TOE_TYPE="short row"
                ;;
        esac
    else
        printf "Choose toe construction (Cuff-Down):\n"
        printf "1) Short Row Toe (wrapped stitches)\n"
        printf "2) Wedge Toe (decreases on sides)\n"
        printf "Choice (1-2): "
        read -r toe_choice

        case "$toe_choice" in
            1)
                TOE_TYPE="short row"
                ;;
            2)
                TOE_TYPE="wedge"
                ;;
            *)
                TOE_TYPE="short row"
                ;;
        esac
    fi
}

get_heel_type() {
    print_section "Heel Type Selection"

    if [ "$CONSTRUCTION_METHOD" = "toe-up" ]; then
        printf "Choose heel construction (Toe-Up):\n"
        printf "1) Short Row Heel (wrapped stitches)\n"
        printf "2) Afterthought Heel (knit leg first, pick up after)\n"
        printf "Choice (1-2): "
        read -r heel_choice

        case "$heel_choice" in
            1)
                HEEL_TYPE="short row"
                ;;
            2)
                HEEL_TYPE="afterthought"
                ;;
            *)
                HEEL_TYPE="short row"
                ;;
        esac
    else
        printf "Choose heel construction (Cuff-Down):\n"
        printf "1) Short Row Heel (wrapped stitches)\n"
        printf "2) Afterthought Heel (knit foot first, pick up after)\n"
        printf "Choice (1-2): "
        read -r heel_choice

        case "$heel_choice" in
            1)
                HEEL_TYPE="short row"
                ;;
            2)
                HEEL_TYPE="afterthought"
                ;;
            *)
                HEEL_TYPE="short row"
                ;;
        esac
    fi
}

get_lengths() {
    print_section "Leg and Cuff Lengths"

    if [ "$CONSTRUCTION_METHOD" = "toe-up" ]; then
        printf "Leg length (from foot to cuff, in %s): " "$UNIT_LENGTH"
    else
        printf "Leg length (from cuff to heel, in %s): " "$UNIT_LENGTH"
    fi
    read -r input_leg_length
    if [ "$MEASUREMENT_UNITS" = "metric" ]; then
        LEG_LENGTH=$(cm_to_inches "$input_leg_length")
    else
        LEG_LENGTH="$input_leg_length"
    fi

    printf "Cuff length (in %s): " "$UNIT_LENGTH"
    read -r input_cuff_length
    if [ "$MEASUREMENT_UNITS" = "metric" ]; then
        CUFF_LENGTH=$(cm_to_inches "$input_cuff_length")
    else
        CUFF_LENGTH="$input_cuff_length"
    fi
}

get_yarn_info() {
    print_section "Yarn Information (Optional)"

    printf "Yarn brand (leave blank to skip): "
    read -r YARN_BRAND

    printf "Yarn line and/or yarn weight (leave blank to skip): "
    read -r YARN_WEIGHT

    printf "Yarn color and/or dye lot (leave blank to skip): "
    read -r YARN_COLOR
}

get_needle_info() {
    print_section "Needle Information"

    printf "Needle size - Enter as US size or mm (e.g., '1' or '2.25mm'): "
    read -r NEEDLE_SIZE

    printf "\nNeedle method:\n"
    printf "1) DPNs (Double-Pointed Needles)\n"
    printf "2) Magic Loop\n"
    printf "3) Short Circulars\n"
    printf "Choice (1-3): "
    read -r needle_method

    case "$needle_method" in
        1)
            NEEDLE_METHOD="DPNs (Double-Pointed Needles)"
            ;;
        2)
            NEEDLE_METHOD="Magic Loop"
            ;;
        3)
            NEEDLE_METHOD="Short Circulars"
            ;;
        *)
            NEEDLE_METHOD="DPNs (Double-Pointed Needles)"
            ;;
    esac
}

# ============================================================================
# CALCULATION FUNCTIONS
# ============================================================================

calculate_cast_on() {
    # Cast-on stitches based on foot circumference and gauge
    # Formula: (foot circumference * stitches per inch) / gauge width
    # Use awk to handle decimal gauge values

    CAST_ON=$(printf "%s\n" "$FOOT_CIRCUMFERENCE" | awk -v gs="$GAUGE_SPI" -v gw="$GAUGE_WIDTH" '{printf "%.0f", ($1 * gs) / gw}')

    # Round to nearest even number for easier ribbing patterns
    if [ $((CAST_ON % 2)) -eq 1 ]; then
        CAST_ON=$((CAST_ON - 1))
    fi
}

calculate_leg_rounds() {
    # Number of rounds for the leg
    # Formula: (leg length * rows per inch) / gauge height
    LEG_ROUNDS=$(printf "%.0f" "$LEG_LENGTH" | awk -v rpi="$GAUGE_RPI" -v gh="$GAUGE_HEIGHT" '{printf "%.0f", ($1 * rpi) / gh}')
}

calculate_cuff_rounds() {
    # Number of rounds for the cuff
    # Formula: (cuff length * rows per inch) / gauge height
    CUFF_ROUNDS=$(printf "%.0f" "$CUFF_LENGTH" | awk -v rpi="$GAUGE_RPI" -v gh="$GAUGE_HEIGHT" '{printf "%.0f", ($1 * rpi) / gh}')
}

calculate_toe_stitches() {
    # Toe stitches: approximately 1/3 of cast-on total
    # For short row toe: stitches left unwrapped at start
    # For wedge toe: cast-on stitches for toe portion
    TOE_ROUNDS=$((CAST_ON / 3))

    # Ensure even number for division onto 2 needles
    if [ $((TOE_ROUNDS % 2)) -eq 1 ]; then
        TOE_ROUNDS=$((TOE_ROUNDS - 1))
    fi

    # Each needle gets half
    TOE_PER_NEEDLE=$((TOE_ROUNDS / 2))
}

calculate_heel_stitches() {
    # Heel flap stitches are half of cast-on
    HEEL_STITCHES=$((CAST_ON / 2))

    # For short row and afterthought heels, the unwrapped/remaining stitches
    # should be approximately 1/3 of the heel stitches
    HEEL_WRAP_STITCHES=$((HEEL_STITCHES / 3))

    # Ensure even number for division onto 2 needles
    if [ $((HEEL_WRAP_STITCHES % 2)) -eq 1 ]; then
        HEEL_WRAP_STITCHES=$((HEEL_WRAP_STITCHES - 1))
    fi

    # Each needle gets half
    HEEL_PER_NEEDLE=$((HEEL_WRAP_STITCHES / 2))
}


# ============================================================================
# REVIEW AND CONFIRM FUNCTIONS
# ============================================================================

display_summary() {
    print_header
    print_section "Pattern Summary - Review Your Selections"

    printf "\n%bCONSTRUCTION METHOD:%b\n" "$BOLD" "$RESET"
    printf "  Method: %s\n" "$CONSTRUCTION_METHOD"
    printf "  Measurement units: %s\n" "$MEASUREMENT_UNITS"

    printf "\n%bFOOT MEASUREMENTS:%b\n" "$BOLD" "$RESET"
    if [ -n "$SHOE_SIZE" ]; then
        printf "  Shoe Size: US %s (%s)\n" "$SHOE_SIZE" "$SHOE_SIZE_TYPE"
    fi
    if [ "$MEASUREMENT_UNITS" = "metric" ]; then
        printf "  Foot length: %.1f cm\n" "$(inches_to_cm "$FOOT_LENGTH")"
        printf "  Foot circumference: %.1f cm\n" "$(inches_to_cm "$FOOT_CIRCUMFERENCE")"
    else
        printf "  Foot length: %.1f inches\n" "$FOOT_LENGTH"
        printf "  Foot circumference: %.1f inches\n" "$FOOT_CIRCUMFERENCE"
    fi

    printf "\n%bGAUGE:%b\n" "$BOLD" "$RESET"
    printf "  Stitch gauge: %.1f stitches per inch\n" "$GAUGE_SPI"
    printf "  Row gauge: %.1f rows per inch\n" "$GAUGE_RPI"

    printf "\n%bPATTERN DETAILS:%b\n" "$BOLD" "$RESET"
    printf "  Leg pattern: %s\n" "$LEG_PATTERN"
    printf "  Cuff pattern: %s\n" "$CUFF_PATTERN"
    printf "  Toe type: %s\n" "$TOE_TYPE"
    printf "  Heel type: %s\n" "$HEEL_TYPE"

    printf "\n%bLENGTHS:%b\n" "$BOLD" "$RESET"
    if [ "$MEASUREMENT_UNITS" = "metric" ]; then
        printf "  Leg length: %.1f cm\n" "$(inches_to_cm "$LEG_LENGTH")"
        printf "  Cuff length: %.1f cm\n" "$(inches_to_cm "$CUFF_LENGTH")"
    else
        printf "  Leg length: %.1f inches\n" "$LEG_LENGTH"
        printf "  Cuff length: %.1f inches\n" "$CUFF_LENGTH"
    fi

    printf "\n%bCALCULATED STITCH COUNTS:%b\n" "$BOLD" "$RESET"
    printf "  Cast-on: %d stitches\n" "$CAST_ON"
    printf "  Leg rounds: %d\n" "$LEG_ROUNDS"
    printf "  Cuff rounds: %d\n" "$CUFF_ROUNDS"
    printf "  Heel stitches: %d\n" "$HEEL_STITCHES"

    # Only show yarn section if user entered any yarn info
    if [ -n "$YARN_BRAND" ] || [ -n "$YARN_WEIGHT" ] || [ -n "$YARN_COLOR" ]; then
        printf "\n%bYARN:%b\n" "$BOLD" "$RESET"
        if [ -n "$YARN_BRAND" ]; then
            printf "  Brand: %s\n" "$YARN_BRAND"
        fi
        if [ -n "$YARN_WEIGHT" ]; then
            printf "  Weight: %s\n" "$YARN_WEIGHT"
        fi
        if [ -n "$YARN_COLOR" ]; then
            printf "  Color/Dye lot: %s\n" "$YARN_COLOR"
        fi
    fi

    printf "\n%bNEEDLES:%b\n" "$BOLD" "$RESET"
    printf "  Size: %s\n" "$NEEDLE_SIZE"
    printf "  Method: %s\n" "$NEEDLE_METHOD"
}

confirm_changes() {
    printf "\n\n%b" "$BOLD"
    printf "Do you want to make any changes? (y/n): "
    printf "%b" "$RESET"
    read -r change_choice

    case "$change_choice" in
        [Yy]*)
            return 0
            ;;
        *)
            return 1
            ;;
    esac
}

edit_selection() {
    print_header
    printf "What would you like to change?\n"
    printf "1) Construction method (cuff-down/toe-up)\n"
    printf "2) Measurement units (imperial/metric)\n"
    printf "3) Foot size\n"
    printf "4) Gauge\n"
    printf "5) Leg pattern\n"
    printf "6) Cuff pattern\n"
    printf "7) Toe type\n"
    printf "8) Heel type\n"
    printf "9) Lengths (leg and cuff)\n"
    printf "10) Yarn information\n"
    printf "11) Needle information\n"
    printf "12) Return to summary\n"
    printf "\nChoice (1-12): "
    read -r edit_choice

    case "$edit_choice" in
        1)
            get_construction_method
            get_toe_type
            get_heel_type
            ;;
        2)
            get_measurement_units
            ;;
        3)
            get_foot_size
            calculate_cast_on
            calculate_toe_stitches
            calculate_heel_stitches
            ;;
        4)
            get_gauge
            calculate_cast_on
            calculate_leg_rounds
            calculate_cuff_rounds
            ;;
        5)
            get_leg_pattern
            ;;
        6)
            get_cuff_pattern
            ;;
        7)
            get_toe_type
            ;;
        8)
            get_heel_type
            ;;
        9)
            get_lengths
            calculate_leg_rounds
            calculate_cuff_rounds
            ;;
        10)
            get_yarn_info
            ;;
        11)
            get_needle_info
            ;;
        12)
            return 1
            ;;
        *)
            printf "Invalid choice.\n"
            pause_for_user
            ;;
    esac
    return 0
}

# ============================================================================
# PATTERN GENERATION FUNCTIONS
# ============================================================================

generate_pattern() {
    PATTERN_TEXT=""

    # Format measurements based on units
    if [ "$MEASUREMENT_UNITS" = "metric" ]; then
        local foot_len=$(inches_to_cm "$FOOT_LENGTH")
        local foot_circ=$(inches_to_cm "$FOOT_CIRCUMFERENCE")
        local leg_len=$(inches_to_cm "$LEG_LENGTH")
        local cuff_len=$(inches_to_cm "$CUFF_LENGTH")
        local unit_display="cm"
    else
        local foot_len="$(printf "%.1f" "$FOOT_LENGTH")"
        local foot_circ="$(printf "%.1f" "$FOOT_CIRCUMFERENCE")"
        local leg_len="$(printf "%.1f" "$LEG_LENGTH")"
        local cuff_len="$(printf "%.1f" "$CUFF_LENGTH")"
        local unit_display="inches"
    fi

    # Calculate actual gauge per inch (divide by measurement width/height)
    local actual_spi=$(printf "%.1f" "$GAUGE_SPI" | awk -v gw="$GAUGE_WIDTH" '{printf "%.1f", $1 / gw}')
    local actual_rpi=$(printf "%.1f" "$GAUGE_RPI" | awk -v gh="$GAUGE_HEIGHT" '{printf "%.1f", $1 / gh}')

    # Format construction method details (order varies by method)
    local construction_details
    if [ "$CONSTRUCTION_METHOD" = "toe-up" ]; then
        construction_details="$CONSTRUCTION_METHOD ($TOE_TYPE toe, $HEEL_TYPE heel)"
    else
        construction_details="$CONSTRUCTION_METHOD ($HEEL_TYPE heel, $TOE_TYPE toe)"
    fi

    PATTERN_TEXT="${PATTERN_TEXT}================================================================================
CUSTOM SOCK KNITTING PATTERN ($CONSTRUCTION_METHOD)
Generated from Basic Sock Pattern Generator
================================================================================

PROJECT DETAILS
==============="

    # Add yarn info if user provided any
    if [ -n "$YARN_BRAND" ] || [ -n "$YARN_WEIGHT" ] || [ -n "$YARN_COLOR" ]; then
        PATTERN_TEXT="${PATTERN_TEXT}
Yarn: $YARN_BRAND, $YARN_WEIGHT, Color: $YARN_COLOR"
    fi

    PATTERN_TEXT="${PATTERN_TEXT}
Needle Size: $NEEDLE_SIZE
Needle Method: $NEEDLE_METHOD

Construction Method: $construction_details

MEASUREMENTS & GAUGE
====================
Foot Length: $foot_len $unit_display
Foot Circumference: $foot_circ $unit_display
Leg Length: $leg_len $unit_display
Cuff Length: $cuff_len $unit_display

Gauge: $actual_spi stitches and $actual_rpi rows per inch

PATTERN CONSTRUCTION
====================

"

    # Different structure for toe-up vs cuff-down
    if [ "$CONSTRUCTION_METHOD" = "toe-up" ]; then
        # Create DPN note if user selected DPNs
        local DPN_NOTE=""
        if [ "$NEEDLE_METHOD" = "DPNs (Double-Pointed Needles)" ]; then
            DPN_NOTE="
Note: It is recommended to use only these two needles for the toe section to maintain the wedge shape and avoid splitting stitches across more needles. You can introduce another needle during the foot section, placing markers to keep the stitches organized as sole and instep."
        fi
        # TOE-UP STRUCTURE: TOE → FOOT → HEEL → LEG → CUFF → (optional HEEL if afterthought)
        case "$TOE_TYPE" in
            "short row")
                PATTERN_TEXT="${PATTERN_TEXT}TOE SECTION (SHORT ROW METHOD) - START HERE
--------
Initial Cast-On:
- Cast on $TOE_ROUNDS stitches total (approximately 1/3 of your finished stitch count)
- Divide: $TOE_PER_NEEDLE stitches on each needle
- Divide evenly onto your chosen needles
- Join in the round carefully

Short Rows:
- Round 1: Knit to last 2 stitches, W&T (wrap and turn)
- Round 2: Purl to last 2 stitches, W&T
- Each round, work to 2 stitches before the gap, W&T
- Continue until only a few stitches remain unwrapped ($HEEL_WRAP_STITCHES stitches unwrapped)
- Pick up wraps and knit them together with their stitches
- You now have approximately $TOE_ROUNDS stitches

Toe Shaping:
- Next, increase evenly to $CAST_ON stitches:
  - Round 1: K1, M1, knit to last 2 stitches, M1, K1 (on each side)
  - Continue increasing until you have $CAST_ON stitches
- Make increases every other round until at full stitch count

"
                ;;
            "wedge")
                PATTERN_TEXT="${PATTERN_TEXT}TOE SECTION (WEDGE TOE WITH JUDY'S MAGIC CAST ON) - START HERE
--------
Setup Wedge Toe:
- Use Judy's Magic method or your preferred closed-toe cast-on (Turkish Cast-On, Figure-Eight Cast-On, etc)
- Cast on $TOE_ROUNDS stitches total
  - $TOE_PER_NEEDLE stitches on top needle
  - $TOE_PER_NEEDLE stitches on bottom needle
- This creates two parallel rows of stitches ready to join

Initial Rounds:
- Knit $TOE_PER_NEEDLE stitches on each needle, joining in the round for $((TOE_PER_NEEDLE * 2)) stitches total
$DPN_NOTE

Wedge Toe Increases:
- Round 1: Knit all stitches
- Round 2: K1, M1R, knit to last stitch on the needle, M1L, K1, repeat on second needle to complete the round
- Repeat rounds 1-2, working increases every other round
- Continue until you have $CAST_ON stitches total (approximately $(( (CAST_ON - TOE_ROUNDS + 3) / 4 * 2 )) rounds of increases)

"
                ;;
        esac

        # FOOT SECTION (for toe-up socks, after toe shaping)
        # Calculate foot rounds accounting for toe and heel based on construction methods
        local foot_total_rounds=$(printf "%.0f" "$FOOT_LENGTH" | awk -v rpi="$GAUGE_RPI" -v gh="$GAUGE_HEIGHT" '{printf "%.0f", ($1 * rpi) / gh}')
        local toe_rounds_used
        local heel_rounds_used

        # Calculate toe rounds based on toe type
        case "$TOE_TYPE" in
            "wedge")
                # Wedge toe increases from TOE_ROUNDS to CAST_ON
                # 4 increases per round, every other round: (change in stitches) / 2
                toe_rounds_used=$(printf "%.0f" | awk -v co="$CAST_ON" -v tr="$TOE_ROUNDS" '{printf "%.0f", (co - tr) / 2}' <<< "")
                ;;
            "short row")
                # Short row toe: wraps down from TOE_ROUNDS to HEEL_WRAP_STITCHES, then increases
                # Wrap phase rows + increase rounds
                toe_rounds_used=$(printf "%.0f" | awk -v tr="$TOE_ROUNDS" -v hw="$HEEL_WRAP_STITCHES" -v co="$CAST_ON" '{printf "%.0f", (tr - hw) + (co - tr) / 2}' <<< "")
                ;;
        esac

        # Calculate heel rounds based on heel type
        case "$HEEL_TYPE" in
            "afterthought")
                # Afterthought heel (wedge reverse): decreases from HEEL_STITCHES to HEEL_WRAP_STITCHES
                # 4 decreases per round, every other round: (change in stitches) / 2
                heel_rounds_used=$(printf "%.0f" | awk -v hs="$HEEL_STITCHES" -v hw="$HEEL_WRAP_STITCHES" '{printf "%.0f", (hs - hw) / 2}' <<< "")
                ;;
            "short row")
                # Short row heel: wraps down and unwraps back up (no flap)
                # Total rows = approximately (HEEL_STITCHES - HEEL_WRAP_STITCHES)
                heel_rounds_used=$(printf "%.0f" | awk -v hs="$HEEL_STITCHES" -v hw="$HEEL_WRAP_STITCHES" '{printf "%.0f", hs - hw}' <<< "")
                ;;
        esac

        local foot_only_rounds=$((foot_total_rounds - toe_rounds_used - heel_rounds_used))
        PATTERN_TEXT="${PATTERN_TEXT}FOOT SECTION
--------
- Continue in stockinette stitch for approximately $foot_only_rounds rounds
- Foot (including toe and heel) should measure a total of $foot_len $unit_display from the beginning

"

        # HEEL PLACEMENT/SETUP (for toe-up socks, before leg)
        case "$HEEL_TYPE" in
            "short row")
                PATTERN_TEXT="${PATTERN_TEXT}HEEL SECTION (SHORT ROW METHOD)
--------
Heel is worked back and forth on $HEEL_STITCHES stitches (half of cast-on).
Estimated rounds: approximately $((HEEL_STITCHES - HEEL_WRAP_STITCHES)) rows

Setup:
- Knit $((CAST_ON / 2)) stitches, turn (leaving remaining stitches on hold for leg)

Short Row Turning:
- Work $((HEEL_STITCHES - 1)) stitches, W&T (wrap and turn)
- Work to 1 stitch before the gap, W&T
- Continue wrapping and turning, working toward center
- Continue until $HEEL_WRAP_STITCHES stitches remain unwrapped (approximately 1/3 of heel stitches: $HEEL_WRAP_STITCHES total, $HEEL_PER_NEEDLE per needle)

Picking Up Wraps:
- Beginning at one end, pick up wraps and knit them together with their stitches
- Work back across all stitches, continuing to pick up wraps as you go
- You should now have $HEEL_STITCHES stitches again, ready to rejoin the leg

"
                ;;
            "afterthought")
                PATTERN_TEXT="${PATTERN_TEXT}HEEL PLACEMENT (AFTERTHOUGHT METHOD)
--------
Setting up for afterthought heel - you'll knit the heel after finishing the cuff.

Heel Marker:
- Knit across $((CAST_ON / 2)) stitches (half the total)
- Replace these $HEEL_STITCHES stitches with waste yarn
  (Knit 2 rows flat with waste yarn over these stitches)
- Continue knitting the remaining $((CAST_ON / 2)) stitches with main yarn

The waste yarn marker now holds your future heel stitches.

"
                ;;
        esac

        # LEG SECTION (for toe-up socks)
        PATTERN_TEXT="${PATTERN_TEXT}LEG SECTION ($leg_len $unit_display / $LEG_ROUNDS rounds)
-------
Pattern: $LEG_PATTERN

Instructions:
- $LEG_PATTERN_NOTES
- Continue for $LEG_ROUNDS rounds
- Leg should measure approximately $leg_len $unit_display from foot

"

        # CUFF SECTION (for toe-up socks)
        PATTERN_TEXT="${PATTERN_TEXT}CUFF SECTION ($cuff_len $unit_display / $CUFF_ROUNDS rounds)
-------
Ribbing pattern: $CUFF_PATTERN_NOTES

Instructions:
- Work $CUFF_ROUNDS rounds of $CUFF_PATTERN
- Bind off loosely in pattern

"

        # AFTERTHOUGHT HEEL INSTRUCTIONS (if applicable, at the very end for toe-up)
        if [ "$HEEL_TYPE" = "afterthought" ]; then
            local afterthought_heel_rounds=$((HEEL_STITCHES - HEEL_WRAP_STITCHES))
            PATTERN_TEXT="${PATTERN_TEXT}HEEL SECTION (AFTERTHOUGHT - work after cuff is complete)
--------
After finishing and binding off the cuff:
Estimated rounds: approximately $afterthought_heel_rounds rounds

Setup for Heel:
- Carefully remove the waste yarn from your heel marker (placed during the heel placement section)
- Pick up $HEEL_STITCHES stitches from below the waste yarn
- Pick up $HEEL_STITCHES stitches from above the waste yarn
- You now have $HEEL_STITCHES stitches for your heel

Short Row Heel Turning:
- Work $((HEEL_STITCHES - 1)) stitches, W&T (wrap and turn)
- Work to 1 stitch before the gap, W&T
- Continue wrapping and turning, working toward center
- Continue until $HEEL_WRAP_STITCHES stitches remain unwrapped (approximately 1/3 of heel stitches: $HEEL_WRAP_STITCHES total, $HEEL_PER_NEEDLE per needle)

Picking Up Wraps:
- Beginning at one end, pick up wraps and knit them together with their stitches
- Work back across all stitches, continuing to pick up wraps as you go
- Graft or bind off remaining stitches

"
        fi

    else
        # CUFF-DOWN STRUCTURE: CUFF → LEG → HEEL → FOOT → TOE → (optional HEEL if afterthought)
        PATTERN_TEXT="${PATTERN_TEXT}CUFF SECTION ($cuff_len $unit_display / $CUFF_ROUNDS rounds) - START HERE
-------
Ribbing pattern: $CUFF_PATTERN_NOTES

Instructions:
- Cast on $CAST_ON stitches loosely using long-tail cast-on
- Join in the round, being careful not to twist
- Work $CUFF_ROUNDS rounds of $CUFF_PATTERN
- Tip: Keep first few stitches loose to avoid tight cuff

"

        # LEG SECTION (for cuff-down socks)
        PATTERN_TEXT="${PATTERN_TEXT}LEG SECTION ($leg_len $unit_display / $LEG_ROUNDS rounds)
-------
Pattern: $LEG_PATTERN

Instructions:
- $LEG_PATTERN_NOTES
- Continue for $LEG_ROUNDS rounds
- Leg should measure approximately $leg_len $unit_display from cuff

"

        # HEEL PLACEMENT/SETUP (for cuff-down socks)
        case "$HEEL_TYPE" in
            "short row")
                PATTERN_TEXT="${PATTERN_TEXT}HEEL SECTION (SHORT ROW METHOD)
--------
Heel is worked back and forth on $HEEL_STITCHES stitches (half of cast-on).
Estimated rows: approximately $((HEEL_STITCHES - HEEL_WRAP_STITCHES)) rows

Setup:
- Knit $((CAST_ON / 2)) stitches, turn (leaving remaining stitches on hold for foot)

Short Row Turning:
- Work $((HEEL_STITCHES - 1)) stitches, W&T (wrap and turn)
- Work to 1 stitch before the gap, W&T
- Continue wrapping and turning, working toward center
- Continue until $HEEL_WRAP_STITCHES stitches remain unwrapped (approximately 1/3 of heel stitches: $HEEL_WRAP_STITCHES total, $HEEL_PER_NEEDLE per needle)

Picking Up Wraps:
- Beginning at one end, pick up wraps and knit them together with their stitches
- Work back across all stitches, continuing to pick up wraps as you go
- You should now have $HEEL_STITCHES stitches again, ready to rejoin the foot

"
                ;;
            "afterthought")
                PATTERN_TEXT="${PATTERN_TEXT}HEEL PLACEMENT (AFTERTHOUGHT METHOD)
--------
Setting up for afterthought heel - you'll knit the heel after completing the foot and toe.

Heel Marker:
- Knit across $((CAST_ON / 2)) stitches (half the total)
- Replace these $HEEL_STITCHES stitches with waste yarn
  (Knit 2 rows with waste yarn over these stitches, return yarn to main ball)
- Continue knitting the remaining $((CAST_ON / 2)) stitches with main yarn

The waste yarn marker now holds your future heel stitches.

"
                ;;
        esac

        # FOOT SECTION (for cuff-down socks, after heel)
        # Calculate foot rounds accounting for heel and toe
        local foot_total_rounds_cd=$(printf "%.0f" "$FOOT_LENGTH" | awk -v rpi="$GAUGE_RPI" -v gh="$GAUGE_HEIGHT" '{printf "%.0f", ($1 * rpi) / gh}')
        local toe_rounds_used_cd
        local heel_rounds_used_cd

        # Calculate toe rounds based on toe type
        case "$TOE_TYPE" in
            "wedge")
                # Wedge toe decreases from CAST_ON to TOE_ROUNDS
                # 4 decreases per round, every other round: (change in stitches) / 2
                toe_rounds_used_cd=$(printf "%.0f" | awk -v co="$CAST_ON" -v tr="$TOE_ROUNDS" '{printf "%.0f", (co - tr) / 2}' <<< "")
                ;;
            "short row")
                # Short row toe: wraps from CAST_ON down to TOE_ROUNDS, then unwraps
                # Wrap-unwrap phase represents the stitches being affected
                toe_rounds_used_cd=$(printf "%.0f" | awk -v co="$CAST_ON" -v tr="$TOE_ROUNDS" '{printf "%.0f", co - tr}' <<< "")
                ;;
        esac

        # Calculate heel rounds based on heel type
        case "$HEEL_TYPE" in
            "short row")
                heel_rounds_used_cd=$(printf "%.0f" | awk -v hs="$HEEL_STITCHES" -v hw="$HEEL_WRAP_STITCHES" '{printf "%.0f", hs - hw}' <<< "")
                ;;
            "afterthought")
                heel_rounds_used_cd=$(printf "%.0f" | awk -v hs="$HEEL_STITCHES" -v hw="$HEEL_WRAP_STITCHES" '{printf "%.0f", (hs - hw) / 2}' <<< "")
                ;;
        esac

        local foot_only_rounds_cd=$((foot_total_rounds_cd - toe_rounds_used_cd - heel_rounds_used_cd))
        PATTERN_TEXT="${PATTERN_TEXT}FOOT SECTION
--------
- Continue in stockinette stitch for approximately $foot_only_rounds_cd rounds
- Foot (including heel and toe) should measure a total of $foot_len $unit_display from back of heel

"

        # TOE SECTION (for cuff-down socks, after foot)
        case "$TOE_TYPE" in
            "short row")
                PATTERN_TEXT="${PATTERN_TEXT}TOE SECTION (SHORT ROW METHOD)
------
Short row toe creates a rounded point and works well with structured feet.

Setup:
- Knit to middle of sole with $CAST_ON stitches
- Begin short rows at center of foot

Toe Decreases:
- Turn work and work back across
- Each row, work to 1-2 stitches before the gap
- Wrap stitch and turn
- Continue until $TOE_ROUNDS stitches remain unwrapped (approximately 1/3 of total stitches)
  - Total remaining stitches: $TOE_ROUNDS ($TOE_PER_NEEDLE per needle)

Finishing:
- Graft remaining stitches using Kitchener stitch
- Or bind off if stitches cannot be grafted

"
                ;;
            "wedge")
                PATTERN_TEXT="${PATTERN_TEXT}TOE SECTION (WEDGE METHOD)
------
Wedge toe uses strategic decreases to create a tapered toe.

Setup:
- Work in stockinette until you need to begin toe decreases
- Divide stitches into 4 sections: right top, left top, right sole, left sole

Decrease Rounds:
- Round 1:
  * Right top: Knit to last 3, K2tog, K1
  * Left top: K1, ssk, knit to end
  * Right sole: Knit to last 3, K2tog, K1
  * Left sole: K1, ssk, knit to end
- Round 2: Knit all stitches
- Alternate decrease rounds and plain knit rounds

Continue until approximately $TOE_ROUNDS stitches remain (approximately 1/3 of total stitches):
  - Target stitches: $TOE_ROUNDS ($TOE_PER_NEEDLE per needle)
- Cut yarn leaving 6-inch tail
- Thread through remaining stitches
- Pull tight and secure

"
                ;;
        esac

        # AFTERTHOUGHT HEEL INSTRUCTIONS (if applicable, at the very end for cuff-down)
        if [ "$HEEL_TYPE" = "afterthought" ]; then
            local afterthought_heel_rounds_cd=$((HEEL_STITCHES - HEEL_WRAP_STITCHES))
            PATTERN_TEXT="${PATTERN_TEXT}HEEL SECTION (AFTERTHOUGHT - work after toe is complete)
--------
After finishing and grafting/binding off the toe:
Estimated rounds: approximately $afterthought_heel_rounds_cd rounds

Setup for Heel:
- Carefully remove the waste yarn from your heel marker (placed during the heel placement section)
- Pick up $HEEL_STITCHES stitches from below the waste yarn
- Pick up $HEEL_STITCHES stitches from above the waste yarn
- You now have $HEEL_STITCHES stitches for your heel

Short Row Heel Turning:
- Work $((HEEL_STITCHES - 1)) stitches, W&T (wrap and turn)
- Work to 1 stitch before the gap, W&T
- Continue wrapping and turning, working toward center
- Continue until $HEEL_WRAP_STITCHES stitches remain unwrapped (approximately 1/3 of heel stitches: $HEEL_WRAP_STITCHES total, $HEEL_PER_NEEDLE per needle)

Picking Up Wraps:
- Beginning at one end, pick up wraps and knit them together with their stitches
- Work back across all stitches, continuing to pick up wraps as you go
- Graft or bind off remaining stitches

"
        fi
    fi

    PATTERN_TEXT="${PATTERN_TEXT}
FINISHING INSTRUCTIONS
======================
1. Weave in all ends using yarn needle
2. Wet block if desired for better fit
3. Let dry flat or on sock blocker
4. Try on with shoes you plan to wear

================================================================================
Pattern generated by Basic Sock Pattern Generator
$construction_details
================================================================================"

}

display_pattern() {
    clear_screen
    printf "%s\n" "$PATTERN_TEXT" | fold -w 80 -s
}

save_pattern() {
    while true; do
        printf "\n\nWhere would you like to save the pattern?\n"
        printf "1) Current directory ($(pwd))\n"
        printf "2) Specify another directory\n"
        printf "Choice (1-2): "
        read -r save_location

        case "$save_location" in
            1)
                save_dir="$(pwd)"
                ;;
            2)
                printf "Enter directory path: "
                read -r save_dir

                # Expand ~ to home directory if present
                save_dir="${save_dir/#\~/$HOME}"

                # Check if directory exists
                if [ ! -d "$save_dir" ]; then
                    printf "Directory does not exist. Create it? (y/n): "
                    read -r create_dir
                    case "$create_dir" in
                        [Yy]*)
                            mkdir -p "$save_dir" || {
                                printf "Failed to create directory: %s\n" "$save_dir"
                                continue
                            }
                            ;;
                        *)
                            printf "Save cancelled.\n"
                            return
                            ;;
                    esac
                fi
                ;;
            *)
                printf "Invalid choice. Using current directory.\n"
                save_dir="$(pwd)"
                ;;
        esac

        printf "\nEnter filename for pattern (without extension): "
        read -r filename

        if [ -z "$filename" ]; then
            filename="sock_pattern"
        fi

        filename="${filename}.txt"
        filepath="${save_dir}/${filename}"

        printf "%s\n" "$PATTERN_TEXT" | fold -w 80 -s > "$filepath"
        printf "\nPattern saved to: %s\n" "$filepath"
        break
    done
}

output_options() {
    print_header
    print_section "Generated Pattern"

    printf "\nWhat would you like to do with your pattern?\n"
    printf "1) Display pattern on screen\n"
    printf "2) Save pattern to file\n"
    printf "3) Both display and save\n"
    printf "4) Regenerate pattern with different options\n"
    printf "5) Done (exit)\n"
    printf "\nChoice (1-5): "
    read -r output_choice

    case "$output_choice" in
        1)
            display_pattern
            pause_for_user
            ;;
        2)
            save_pattern
            pause_for_user
            ;;
        3)
            display_pattern
            pause_for_user
            save_pattern
            ;;
        4)
            while edit_selection; do
                calculate_cast_on
                calculate_leg_rounds
                calculate_cuff_rounds
                calculate_toe_stitches
                calculate_heel_stitches
            done
            generate_pattern
            return 0
            ;;
        5)
            return 1
            ;; 
        *)
            printf "Invalid choice.\n"
            pause_for_user
            return 0
            ;;
    esac
    return 0
}

# ============================================================================
# MAIN FLOW
# ============================================================================

main() {
    # Display welcome message
    clear_screen
    print_welcome
    pause_for_user

    # Gather all input
    get_construction_method
    get_measurement_units
    get_foot_size
    get_gauge
    get_leg_pattern
    get_cuff_pattern
    get_toe_type
    get_heel_type
    get_lengths
    get_yarn_info
    get_needle_info

    # Calculate values
    calculate_cast_on
    calculate_leg_rounds
    calculate_cuff_rounds
    calculate_toe_stitches
    calculate_heel_stitches

    # Review and allow changes
    while true; do
        display_summary
        if ! confirm_changes; then
            break
        fi
        while edit_selection; do
            calculate_cast_on
            calculate_leg_rounds
            calculate_cuff_rounds
            calculate_toe_stitches
            calculate_heel_stitches
            display_summary
            if ! confirm_changes; then
                break 2
            fi
        done
    done

    # Generate and display pattern
    generate_pattern

    while output_options; do
        :
    done

    print_header
    printf "Thank you for using the Basic Sock Pattern Generator!\n"
    printf "Happy knitting!\n\n"
}

# Run main function
main "$@"