import type { HttpContext } from '@adonisjs/core/http'
import ConfigurationService, {
  type ConfigurationFilters,
  type CreateConfigurationDto,
  type UpdateConfigurationDto,
} from '#services/configuration_service'
import ConfigurationEngine from '#services/configuration_engine'
import ConfigurationModel from '#models/configuration'
import logger from '@adonisjs/core/services/logger'

/**
 * Configurations API Controller
 * 
 * Handles REST endpoints for Configuration management:
 * - GET /api/v1/configurations (list with pagination and filters)
 * - GET /api/v1/configurations/:id (get single with compliance stats)
 * - POST /api/v1/configurations (create with validation and overlap detection)
 * - PUT /api/v1/configurations/:id (update with validation and overlap detection)
 * - DELETE /api/v1/configurations/:id (delete)
 * - PATCH /api/v1/configurations/:id/toggle (toggle enabled status)
 * - PATCH /api/v1/configurations/:id/tags (add/remove tags)
 * - GET /api/v1/configurations/:id/history (version history)
 * - POST /api/v1/configurations/:id/dry-run (dry-run evaluation)
 */
export default class ConfigurationsController {
  private configService: ConfigurationService
  private engine: ConfigurationEngine

  constructor() {
    this.configService = new ConfigurationService()
    this.engine = new ConfigurationEngine()
  }

  /**
   * GET /api/v1/configurations
   * List configurations with pagination and filters
   */
  async index({ request, response }: HttpContext) {
    try {
      const filters: ConfigurationFilters = {
        page: Number(request.input('page', 1)),
        perPage: Number(request.input('perPage', 20)),
        tag: request.input('tag'),
        name: request.input('name') || undefined,
        enabled: request.input('enabled') !== undefined ? request.input('enabled') === 'true' : undefined,
        productClass: request.input('productClass'),
      }

      const result = await this.configService.findAll(filters)
      return response.ok(result)
    } catch (error: any) {
      logger.error({ error: error.message }, '[ConfigAPI] List configurations failed')
      return response.status(500).json({ message: 'Failed to list configurations' })
    }
  }

  /**
   * GET /api/v1/configurations/tags
   * Return all distinct tags across configurations
   */
  async listTags({ response }: HttpContext) {
    try {
      const tags = await ConfigurationModel.distinctTags()
      return response.ok(tags)
    } catch (error: any) {
      return response.status(500).json({ message: 'Failed to list tags' })
    }
  }

  /**
   * GET /api/v1/configurations/:id
   * Get single configuration with compliance statistics
   */
  async show({ params, response }: HttpContext) {
    try {
      const config = await this.configService.findById(params.id)
      if (!config) {
        return response.status(404).json({ message: 'Configuration not found' })
      }

      // TODO: Add compliance statistics from device compliance info
      return response.ok(config)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Get configuration failed')
      return response.status(500).json({ message: 'Failed to retrieve configuration' })
    }
  }

  /**
   * POST /api/v1/configurations
   * Create new configuration with validation and overlap detection
   */
  async store({ request, response }: HttpContext) {
    try {
      const data = request.only([
        'identifier',
        'name',
        'version',
        'priority',
        'policy',
        'enabled',
        'tags',
        'criteria',
        'inventory',
        'desiredParameters',
        'firmwareTarget',
        'schedule',
      ]) as CreateConfigurationDto

      // Check for overlaps
      const overlapResult = await this.configService.detectOverlap(data.criteria || {}, data.priority)
      if (overlapResult && overlapResult.overlappingConfigurations && overlapResult.overlappingConfigurations.length > 0 && !request.input('ignoreOverlap')) {
        return response.status(409).json({
          message: 'Configuration overlaps with existing ones',
          overlaps: overlapResult.overlappingConfigurations,
        })
      }

      // Create configuration
      const config = await this.configService.create(data)
      return response.status(201).json(config)
    } catch (error: any) {
      logger.error({ error: error.message }, '[ConfigAPI] Create configuration failed')
      if (error.field) {
        return response.status(422).json({ message: error.message, field: error.field })
      }
      return response.status(500).json({ message: 'Failed to create configuration' })
    }
  }

  /**
   * PUT /api/v1/configurations/:id
   * Update configuration with validation and overlap detection
   */
  async update({ params, request, response }: HttpContext) {
    try {
      const data = request.only([
        'name',
        'priority',
        'policy',
        'enabled',
        'tags',
        'criteria',
        'inventory',
        'desiredParameters',
        'firmwareTarget',
        'schedule',
        'bumpType',
      ]) as UpdateConfigurationDto

      // Check for overlaps if priority changed
      if (data.priority) {
        const overlapResult = await this.configService.detectOverlap(
          data.criteria || {},
          data.priority,
          params.id
        )
      if (overlapResult && overlapResult.overlappingConfigurations && overlapResult.overlappingConfigurations.length > 0 && !request.input('ignoreOverlap')) {
        return response.status(409).json({
          message: 'Configuration overlaps with existing ones',
          overlaps: overlapResult.overlappingConfigurations,
        })
      }
    }

      // Update configuration
      const config = await this.configService.update(params.id, data)
      if (!config) {
        return response.status(404).json({ message: 'Configuration not found' })
      }

      return response.ok(config)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Update configuration failed')
      if (error.field) {
        return response.status(422).json({ message: error.message, field: error.field })
      }
      return response.status(500).json({ message: 'Failed to update configuration' })
    }
  }

  /**
   * DELETE /api/v1/configurations/:id
   * Delete configuration
   */
  async destroy({ params, response }: HttpContext) {
    try {
      await this.configService.delete(params.id)
      return response.status(204).send(null)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Delete configuration failed')
      return response.status(500).json({ message: 'Failed to delete configuration' })
    }
  }

  /**
   * PATCH /api/v1/configurations/:id/toggle
   * Toggle enabled status
   */
  async toggleEnabled({ params, request, response }: HttpContext) {
    try {
      const enabled = request.input('enabled') as boolean
      const config = await this.configService.toggleEnabled(params.id, enabled)
      if (!config) {
        return response.status(404).json({ message: 'Configuration not found' })
      }
      return response.ok(config)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Toggle configuration failed')
      return response.status(500).json({ message: 'Failed to toggle configuration' })
    }
  }

  /**
   * PATCH /api/v1/configurations/:id/tags
   * Add or remove tags
   */
  async manageTags({ params, request, response }: HttpContext) {
    try {
      const action = request.input('action') as 'add' | 'remove'
      const tag = request.input('tag') as string

      if (!action || !['add', 'remove'].includes(action)) {
        return response.status(422).json({ message: 'Invalid action: must be "add" or "remove"' })
      }

      if (!tag) {
        return response.status(422).json({ message: 'Tag is required' })
      }

      const config = await this.configService.findById(params.id)
      if (!config) {
        return response.status(404).json({ message: 'Configuration not found' })
      }

      if (action === 'add') {
        if (!config.tags.includes(tag)) {
          config.tags.push(tag)
        }
      } else {
        const index = config.tags.indexOf(tag)
        if (index > -1) {
          config.tags.splice(index, 1)
        }
      }

      const updated = await this.configService.update(params.id, { tags: config.tags })
      return response.ok(updated)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Manage tags failed')
      return response.status(500).json({ message: 'Failed to manage tags' })
    }
  }

  /**
   * GET /api/v1/configurations/:id/history
   * Get configuration version history
   */
  async history({ params, request, response }: HttpContext) {
    try {
      const page = Number(request.input('page', 1))
      const limit = Number(request.input('limit', 10))

      const result = await this.configService.getHistory(params.id, page, limit)
      return response.ok(result)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Get history failed')
      return response.status(500).json({ message: 'Failed to retrieve configuration history' })
    }
  }

  /**
   * GET /api/v1/configurations/:id/compliance
   * Compliance report: all devices matching criteria + their compliance status
   */
  async compliance({ params, response }: HttpContext) {
    try {
      const report = await this.engine.complianceReport(params.id)
      return response.ok(report)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Compliance report failed')
      if (error.message.includes('not found')) {
        return response.status(404).json({ message: error.message })
      }
      return response.status(500).json({ message: 'Compliance report failed' })
    }
  }

  /**
   * POST /api/v1/configurations/:id/dry-run
   * Perform dry-run evaluation for a device
   */
  async dryRun({ params, request, response }: HttpContext) {
    try {
      const deviceIdentifier = request.input('deviceIdentifier') as string

      if (!deviceIdentifier) {
        return response.status(422).json({ message: 'deviceIdentifier is required' })
      }

      const result = await this.engine.dryRun(params.id, deviceIdentifier)
      return response.ok(result)
    } catch (error: any) {
      logger.error({ error: error.message, id: params.id }, '[ConfigAPI] Dry-run failed')
      if (error.message.includes('not found')) {
        return response.status(404).json({ message: error.message })
      }
      return response.status(500).json({ message: 'Dry-run failed' })
    }
  }
}