rules-migrator.ts

// kilocode_change - new file

import * as fs from "fs/promises"
import * as path from "path"
import os from "os"

export namespace RulesMigrator {
  // Only support .kilocoderules (no migration for .roorules or .clinerules)
  const LEGACY_RULE_FILE = ".kilocoderules"

  // Directory-based rules
  const KILOCODE_RULES_DIR = ".kilocode/rules"
  const GLOBAL_RULES_DIR = path.join(os.homedir(), ".kilocode", "rules")

  // Known modes for mode-specific rule discovery
  const KNOWN_MODES = ["code", "architect", "ask", "debug", "orchestrator"]

  export interface RuleFile {
    path: string
    source: "global" | "project" | "legacy"
    mode?: string // e.g., "code", "architect" - undefined means applies to all modes
  }

  export interface MigrationResult {
    instructions: string[]
    warnings: string[]
  }

  async function exists(filepath: string): Promise<boolean> {
    return Bun.file(filepath).exists()
  }

  async function isDirectory(filepath: string): Promise<boolean> {
    try {
      const stat = await fs.stat(filepath)
      return stat.isDirectory()
    } catch {
      return false
    }
  }

  async function findMarkdownFiles(dir: string): Promise<string[]> {
    try {
      const entries = await fs.readdir(dir, { withFileTypes: true })
      return entries.filter((e) => e.isFile() && e.name.endsWith(".md")).map((e) => path.join(dir, e.name))
    } catch {
      return []
    }
  }

  export async function discoverRules(projectDir: string): Promise<RuleFile[]> {
    const rules: RuleFile[] = []

    // 1. Global rules directory (~/.kilocode/rules/*.md)
    if (await isDirectory(GLOBAL_RULES_DIR)) {
      const files = await findMarkdownFiles(GLOBAL_RULES_DIR)
      for (const file of files) {
        rules.push({ path: file, source: "global" })
      }
    }

    // 2. Project .kilocode/rules/ directory
    const projectRulesDir = path.join(projectDir, KILOCODE_RULES_DIR)
    if (await isDirectory(projectRulesDir)) {
      const files = await findMarkdownFiles(projectRulesDir)
      for (const file of files) {
        rules.push({ path: file, source: "project" })
      }
    }

    // 3. Legacy .kilocoderules file (only kilocode, not roo/cline)
    const legacyFile = path.join(projectDir, LEGACY_RULE_FILE)
    if (await exists(legacyFile)) {
      rules.push({ path: legacyFile, source: "legacy" })
    }

    // 4. Mode-specific rules
    for (const mode of KNOWN_MODES) {
      // Mode-specific directory (.kilocode/rules-{mode}/*.md)
      const modeDir = path.join(projectDir, `.kilocode/rules-${mode}`)
      if (await isDirectory(modeDir)) {
        const files = await findMarkdownFiles(modeDir)
        for (const file of files) {
          rules.push({ path: file, source: "project", mode })
        }
      }

      // Legacy mode-specific file (.kilocoderules-{mode})
      const legacyModeFile = path.join(projectDir, `.kilocoderules-${mode}`)
      if (await exists(legacyModeFile)) {
        rules.push({ path: legacyModeFile, source: "legacy", mode })
      }
    }

    return rules
  }

  export async function migrate(options: {
    projectDir: string
    includeGlobal?: boolean
    includeModeSpecific?: boolean
  }): Promise<MigrationResult> {
    const warnings: string[] = []
    const instructions: string[] = []
    const includeGlobal = options.includeGlobal ?? true
    const includeModeSpecific = options.includeModeSpecific ?? true

    const rules = await discoverRules(options.projectDir)

    for (const rule of rules) {
      // Skip global if not requested
      if (rule.source === "global" && !includeGlobal) {
        continue
      }

      // Skip mode-specific if not requested
      if (rule.mode && !includeModeSpecific) {
        warnings.push(`Mode-specific rule '${path.basename(rule.path)}' skipped (mode: ${rule.mode})`)
        continue
      }

      // Add to instructions array
      instructions.push(rule.path)

      // Warn about legacy files
      if (rule.source === "legacy") {
        warnings.push(
          `Legacy rule file '${path.basename(rule.path)}' found. ` +
            `Consider migrating to .kilocode/rules/ directory.`,
        )
      }
    }

    return { instructions, warnings }
  }
}