cli_tool.py

#!/usr/bin/env python3
"""Interactive CLI client for the Ticket Booking API.

This script communicates with the API exclusively over HTTP.
It MUST NOT import anything from the app package.
"""

from __future__ import annotations

import argparse
import os
import sys
from typing import Any

import requests

DEFAULT_BASE_URL = "http://localhost:5000"

MENU = """
========================================
  Ticket Booking CLI Client
========================================
1. Check API Health
2. List Events
3. List Tickets
4. Book a Ticket
0. Exit
========================================
"""


def _url(base: str, path: str) -> str:
    """Build a full URL from base and path."""
    return f"{base.rstrip('/')}{path}"


def _print_table(headers: list[str], rows: list[list[str]]) -> None:
    """Print a simple aligned text table."""
    if not rows:
        print("  (no data)")
        return

    widths = [len(h) for h in headers]
    for row in rows:
        for i, cell in enumerate(row):
            widths[i] = max(widths[i], len(cell))

    fmt = "  ".join(f"{{:<{w}}}" for w in widths)
    print(fmt.format(*headers))
    print(fmt.format(*["-" * w for w in widths]))
    for row in rows:
        print(fmt.format(*row))


def check_health(base_url: str) -> None:
    """Check API health endpoint."""
    try:
        resp = requests.get(_url(base_url, "/api/health"), timeout=5)
        resp.raise_for_status()
        data: dict[str, Any] = resp.json()
    except requests.RequestException as exc:
        print(f"  Error  : failed to check API health: {exc}")
        return
    except ValueError:
        print("  Error  : health endpoint returned a non-JSON response")
        return
    print(f"  Status : {data.get('status', 'unknown')}")
    print(f"  Message: {data.get('message', '')}")


def list_events(base_url: str) -> None:
    """List all events."""
    resp = requests.get(_url(base_url, "/api/events"), timeout=5)
    resp.raise_for_status()
    events: list[dict[str, Any]] = resp.json()

    rows = [
        [str(e["id"]), e["name"], e["date"], e.get("description", "")] for e in events
    ]
    _print_table(["ID", "Name", "Date", "Description"], rows)


def list_tickets(base_url: str) -> None:
    """List all tickets."""
    resp = requests.get(_url(base_url, "/api/tickets"), timeout=5)
    resp.raise_for_status()
    tickets: list[dict[str, Any]] = resp.json()

    rows = [[str(t["id"]), str(t["event_id"]), t.get("details", "")] for t in tickets]
    _print_table(["ID", "Event ID", "Details"], rows)


def book_ticket(base_url: str) -> None:
    """Attempt to book a ticket by prompting for ticket ID and quantity."""
    try:
        ticket_id_str = input("  Enter Ticket ID: ").strip()
        ticket_id = int(ticket_id_str)
    except (ValueError, EOFError):
        print("  Invalid ticket ID.")
        return

    try:
        quantity_str = input("  Enter Quantity [1]: ").strip() or "1"
        quantity = int(quantity_str)
    except (ValueError, EOFError):
        print("  Invalid quantity.")
        return

    resp = requests.post(
        _url(base_url, f"/api/tickets/{ticket_id}/reserve"),
        json={"quantity": quantity},
        timeout=5,
    )

    try:
        data: Any = resp.json()
    except ValueError:
        data = resp.text

    if resp.ok:
        print(f"  Booking successful: {data}")
    else:
        error_message = data.get("error", data) if isinstance(data, dict) else data
        print(f"  Booking failed ({resp.status_code}): {error_message}")


def main() -> None:
    """Run the interactive CLI client."""
    parser = argparse.ArgumentParser(description="Ticket Booking CLI Client")
    parser.add_argument(
        "--base-url",
        default=os.getenv("API_BASE_URL", DEFAULT_BASE_URL),
        help=f"Base URL of the API (default: {DEFAULT_BASE_URL})",
    )
    args = parser.parse_args()
    base_url: str = args.base_url

    print(f"\n  Connecting to API at: {base_url}")

    actions: dict[str, tuple[str, Any]] = {
        "1": ("Check API Health", lambda: check_health(base_url)),
        "2": ("List Events", lambda: list_events(base_url)),
        "3": ("List Tickets", lambda: list_tickets(base_url)),
        "4": ("Book a Ticket", lambda: book_ticket(base_url)),
    }

    while True:
        print(MENU)
        try:
            choice = input("Select an option: ").strip()
        except (EOFError, KeyboardInterrupt):
            print("\n  Goodbye!")
            sys.exit(0)

        if choice == "0":
            print("  Goodbye!")
            break

        action = actions.get(choice)
        if action is None:
            print("  Invalid option. Try again.")
            continue

        label, func = action
        print(f"\n  --- {label} ---")
        try:
            func()
        except requests.ConnectionError:
            print(f"  Cannot connect to API at {base_url}")
            print("  Is the server running?")
        except requests.RequestException as exc:
            print(f"  Request error: {exc}")


if __name__ == "__main__":
    main()