/**
 * Sync Route Handler
 *
 * Endpoint for triggering synchronization with cloud providers.
 * Validates request parameters and orchestrates sync operations.
 */

import type { Env, SyncReport } from '../types';

/**
 * Request body interface for sync endpoint
 */
interface SyncRequestBody {
  providers?: string[];
  force?: boolean;
}

/**
 * Supported cloud providers
 */
const SUPPORTED_PROVIDERS = ['linode', 'vultr', 'aws'] as const;
type SupportedProvider = typeof SUPPORTED_PROVIDERS[number];

/**
 * Validate if provider is supported
 */
function isSupportedProvider(provider: string): provider is SupportedProvider {
  return SUPPORTED_PROVIDERS.includes(provider as SupportedProvider);
}

/**
 * Handle POST /sync endpoint
 *
 * @param request - HTTP request object
 * @param env - Cloudflare Worker environment bindings
 * @returns JSON response with sync results
 *
 * @example
 * POST /sync
 * {
 *   "providers": ["linode"],
 *   "force": false
 * }
 */
export async function handleSync(
  request: Request,
  _env: Env
): Promise<Response> {
  const startTime = Date.now();
  const startedAt = new Date().toISOString();

  console.log('[Sync] Request received', { timestamp: startedAt });

  try {
    // Parse and validate request body
    let body: SyncRequestBody = {};

    try {
      const contentType = request.headers.get('content-type');
      if (contentType && contentType.includes('application/json')) {
        body = await request.json() as SyncRequestBody;
      }
    } catch (error) {
      console.error('[Sync] Invalid JSON in request body', { error });
      return Response.json(
        {
          success: false,
          error: {
            code: 'INVALID_REQUEST',
            message: 'Invalid JSON in request body',
            details: error instanceof Error ? error.message : 'Unknown error'
          }
        },
        { status: 400 }
      );
    }

    // Validate providers array
    const providers = body.providers || ['linode'];

    if (!Array.isArray(providers)) {
      console.error('[Sync] Providers must be an array', { providers });
      return Response.json(
        {
          success: false,
          error: {
            code: 'INVALID_PROVIDERS',
            message: 'Providers must be an array',
            details: { received: typeof providers }
          }
        },
        { status: 400 }
      );
    }

    if (providers.length === 0) {
      console.error('[Sync] Providers array is empty');
      return Response.json(
        {
          success: false,
          error: {
            code: 'EMPTY_PROVIDERS',
            message: 'At least one provider must be specified',
            details: null
          }
        },
        { status: 400 }
      );
    }

    // Validate each provider
    const unsupportedProviders: string[] = [];
    for (const provider of providers) {
      if (typeof provider !== 'string') {
        console.error('[Sync] Provider must be a string', { provider });
        return Response.json(
          {
            success: false,
            error: {
              code: 'INVALID_PROVIDER_TYPE',
              message: 'Each provider must be a string',
              details: { provider, type: typeof provider }
            }
          },
          { status: 400 }
        );
      }

      if (!isSupportedProvider(provider)) {
        unsupportedProviders.push(provider);
      }
    }

    if (unsupportedProviders.length > 0) {
      console.error('[Sync] Unsupported providers', { unsupportedProviders });
      return Response.json(
        {
          success: false,
          error: {
            code: 'UNSUPPORTED_PROVIDERS',
            message: `Unsupported providers: ${unsupportedProviders.join(', ')}`,
            details: {
              unsupported: unsupportedProviders,
              supported: SUPPORTED_PROVIDERS
            }
          }
        },
        { status: 400 }
      );
    }

    const force = body.force === true;

    console.log('[Sync] Validation passed', { providers, force });

    // TODO: Once SyncOrchestrator is implemented, use it here
    // For now, return a placeholder response

    // const syncOrchestrator = new SyncOrchestrator(env.DB, env.VAULT_URL, env.VAULT_TOKEN);
    // const syncReport = await syncOrchestrator.syncProviders(providers, force);

    // Placeholder sync report
    const completedAt = new Date().toISOString();
    const totalDuration = Date.now() - startTime;
    const syncId = `sync_${Date.now()}`;

    console.log('[Sync] TODO: Implement actual sync logic');
    console.log('[Sync] Placeholder response generated', { syncId, totalDuration });

    // Return placeholder success response
    const placeholderReport: SyncReport = {
      success: true,
      started_at: startedAt,
      completed_at: completedAt,
      total_duration_ms: totalDuration,
      providers: providers.map(providerName => ({
        provider: providerName,
        success: true,
        regions_synced: 0,
        instances_synced: 0,
        pricing_synced: 0,
        duration_ms: 0,
      })),
      summary: {
        total_providers: providers.length,
        successful_providers: providers.length,
        failed_providers: 0,
        total_regions: 0,
        total_instances: 0,
        total_pricing: 0,
      }
    };

    return Response.json(
      {
        success: true,
        data: {
          sync_id: syncId,
          ...placeholderReport
        }
      },
      { status: 200 }
    );

  } catch (error) {
    console.error('[Sync] Unexpected error', { error });

    const completedAt = new Date().toISOString();
    const totalDuration = Date.now() - startTime;

    return Response.json(
      {
        success: false,
        error: {
          code: 'SYNC_FAILED',
          message: 'Sync operation failed',
          details: {
            error: error instanceof Error ? error.message : 'Unknown error',
            duration_ms: totalDuration,
            started_at: startedAt,
            completed_at: completedAt
          }
        }
      },
      { status: 500 }
    );
  }
}