/**
 * Resource Locator - Centralized file path resolution and caching
 * Reduces duplicate file system operations and memory usage
 */

const path = require('node:path')
const fs = require('fs-extra')
const moduleManager = require('./module-manager')

class ResourceLocator {
  constructor () {
    this._pathCache = new Map()
    this._globCache = new Map()
    this._bmadCorePath = null
    this._expansionPacksPath = null
  }

  /**
   * Get the base path for bmad-core
   */
  getBmadCorePath () {
    if (!this._bmadCorePath) {
      this._bmadCorePath = path.join(__dirname, '../../../bmad-core')
    }
    return this._bmadCorePath
  }

  /**
   * Get the base path for expansion packs
   */
  getExpansionPacksPath () {
    if (!this._expansionPacksPath) {
      this._expansionPacksPath = path.join(__dirname, '../../../expansion-packs')
    }
    return this._expansionPacksPath
  }

  /**
   * Find all files matching a pattern, with caching
   * @param {string} pattern - Glob pattern
   * @param {Object} options - Glob options
   * @returns {Promise<string[]>} Array of matched file paths
   */
  async findFiles (pattern, options = {}) {
    const cacheKey = `${pattern}:${JSON.stringify(options)}`

    if (this._globCache.has(cacheKey)) {
      return this._globCache.get(cacheKey)
    }

    const { glob } = await moduleManager.getModules(['glob'])
    const files = await glob(pattern, options)

    // Cache for 5 minutes
    this._globCache.set(cacheKey, files)
    setTimeout(() => this._globCache.delete(cacheKey), 5 * 60 * 1000)

    return files
  }

  /**
   * Get agent path with caching
   * @param {string} agentId - Agent identifier
   * @returns {Promise<string|null>} Path to agent file or null if not found
   */
  async getAgentPath (agentId) {
    const cacheKey = `agent:${agentId}`

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    // Check in bmad-core
    let agentPath = path.join(this.getBmadCorePath(), 'agents', `${agentId}.md`)
    if (await fs.pathExists(agentPath)) {
      this._pathCache.set(cacheKey, agentPath)
      return agentPath
    }

    // Check in expansion packs
    const expansionPacks = await this.getExpansionPacks()
    for (const pack of expansionPacks) {
      agentPath = path.join(pack.path, 'agents', `${agentId}.md`)
      if (await fs.pathExists(agentPath)) {
        this._pathCache.set(cacheKey, agentPath)
        return agentPath
      }
    }

    return null
  }

  /**
   * Get available agents with metadata
   * @returns {Promise<Array>} Array of agent objects
   */
  async getAvailableAgents () {
    const cacheKey = 'all-agents'

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    const agents = []
    const yaml = require('js-yaml')
    const { extractYamlFromAgent } = require('../../lib/yaml-utils')

    // Get agents from bmad-core
    const coreAgents = await this.findFiles('agents/*.md', {
      cwd: this.getBmadCorePath()
    })

    for (const agentFile of coreAgents) {
      const content = await fs.readFile(
        path.join(this.getBmadCorePath(), agentFile),
        'utf8'
      )
      const yamlContent = extractYamlFromAgent(content)
      if (yamlContent) {
        try {
          const metadata = yaml.load(yamlContent)
          agents.push({
            id: path.basename(agentFile, '.md'),
            name: metadata.agent_name || path.basename(agentFile, '.md'),
            description: metadata.description || 'No description available',
            source: 'core'
          })
        } catch (e) {
          // Skip invalid agents
        }
      }
    }

    // Cache for 10 minutes
    this._pathCache.set(cacheKey, agents)
    setTimeout(() => this._pathCache.delete(cacheKey), 10 * 60 * 1000)

    return agents
  }

  /**
   * Get available expansion packs
   * @returns {Promise<Array>} Array of expansion pack objects
   */
  async getExpansionPacks () {
    const cacheKey = 'expansion-packs'

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    const packs = []
    const expansionPacksPath = this.getExpansionPacksPath()

    if (await fs.pathExists(expansionPacksPath)) {
      const entries = await fs.readdir(expansionPacksPath, { withFileTypes: true })

      for (const entry of entries) {
        if (entry.isDirectory()) {
          const configPath = path.join(expansionPacksPath, entry.name, 'config.yaml')
          if (await fs.pathExists(configPath)) {
            try {
              const yaml = require('js-yaml')
              const config = yaml.load(await fs.readFile(configPath, 'utf8'))
              packs.push({
                id: entry.name,
                name: config.name || entry.name,
                version: config.version || '1.0.0',
                description: config.description || 'No description available',
                shortTitle: config['short-title'] || config.description || 'No description available',
                author: config.author || 'Unknown',
                path: path.join(expansionPacksPath, entry.name)
              })
            } catch (e) {
              // Skip invalid packs
            }
          }
        }
      }
    }

    // Cache for 10 minutes
    this._pathCache.set(cacheKey, packs)
    setTimeout(() => this._pathCache.delete(cacheKey), 10 * 60 * 1000)

    return packs
  }

  /**
   * Get team configuration
   * @param {string} teamId - Team identifier
   * @returns {Promise<Object|null>} Team configuration or null
   */
  async getTeamConfig (teamId) {
    const cacheKey = `team:${teamId}`

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    const teamPath = path.join(this.getBmadCorePath(), 'agent-teams', `${teamId}.yaml`)

    if (await fs.pathExists(teamPath)) {
      try {
        const yaml = require('js-yaml')
        const content = await fs.readFile(teamPath, 'utf8')
        const config = yaml.load(content)
        this._pathCache.set(cacheKey, config)
        return config
      } catch (e) {
        return null
      }
    }

    return null
  }

  /**
   * Get resource dependencies for an agent
   * @param {string} agentId - Agent identifier
   * @returns {Promise<Object>} Dependencies object
   */
  async getAgentDependencies (agentId) {
    const cacheKey = `deps:${agentId}`

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    const agentPath = await this.getAgentPath(agentId)
    if (!agentPath) {
      return { all: [], byType: {} }
    }

    const content = await fs.readFile(agentPath, 'utf8')
    const { extractYamlFromAgent } = require('../../lib/yaml-utils')
    const yamlContent = extractYamlFromAgent(content)

    if (!yamlContent) {
      return { all: [], byType: {} }
    }

    try {
      const yaml = require('js-yaml')
      const metadata = yaml.load(yamlContent)
      const dependencies = metadata.dependencies || {}

      // Flatten dependencies
      const allDeps = []
      const byType = {}

      for (const [type, deps] of Object.entries(dependencies)) {
        if (Array.isArray(deps)) {
          byType[type] = deps
          for (const dep of deps) {
            allDeps.push(`.bmad-core/${type}/${dep}`)
          }
        }
      }

      const result = { all: allDeps, byType }
      this._pathCache.set(cacheKey, result)
      return result
    } catch (e) {
      return { all: [], byType: {} }
    }
  }

  /**
   * Clear all caches to free memory
   */
  clearCache () {
    this._pathCache.clear()
    this._globCache.clear()
  }

  /**
   * Get IDE configuration
   * @param {string} ideId - IDE identifier
   * @returns {Promise<Object|null>} IDE configuration or null
   */
  async getIdeConfig (ideId) {
    const cacheKey = `ide:${ideId}`

    if (this._pathCache.has(cacheKey)) {
      return this._pathCache.get(cacheKey)
    }

    const idePath = path.join(this.getBmadCorePath(), 'ide-rules', `${ideId}.yaml`)

    if (await fs.pathExists(idePath)) {
      try {
        const yaml = require('js-yaml')
        const content = await fs.readFile(idePath, 'utf8')
        const config = yaml.load(content)
        this._pathCache.set(cacheKey, config)
        return config
      } catch (e) {
        return null
      }
    }

    return null
  }
}

// Singleton instance
const resourceLocator = new ResourceLocator()

module.exports = resourceLocator