/**
 * Posts Module - API Routes
 */

import {
  createPost,
  getPostById,
  getPostBySlug,
  getPosts,
  searchPosts,
  updatePost,
  deletePost
} from './crud.js';

import {
  createCategory,
  getCategoryById,
  getCategories,
  getActiveCategories,
  updateCategory,
  deleteCategory
} from './categories/crud.js';

import {
  uploadImage,
  deleteFile,
  generateBlogFilePath,
  generateUniqueFilename,
  validateUpload,
  FILE_TYPE_PRESETS,
  FILE_SIZE_LIMITS
} from '@zen/core/storage';

import { getPostsConfig, getPostType } from './config.js';

// ============================================================================
// Config
// ============================================================================

async function handleGetConfig() {
  try {
    const config = getPostsConfig();
    return { success: true, config };
  } catch (error) {
    return { success: false, error: error.message || 'Failed to get config' };
  }
}

// ============================================================================
// Posts (admin)
// ============================================================================

async function handleGetPosts(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    if (!postType) return { success: false, error: 'Post type is required' };
    if (!getPostType(postType)) return { success: false, error: `Unknown post type: ${postType}` };

    const id = url.searchParams.get('id');
    if (id) {
      const post = await getPostById(postType, parseInt(id));
      if (!post) return { success: false, error: 'Post not found' };
      return { success: true, post };
    }

    const page = parseInt(url.searchParams.get('page')) || 1;
    const limit = parseInt(url.searchParams.get('limit')) || 20;
    const search = url.searchParams.get('search') || '';
    const category_id = url.searchParams.get('category_id') || null;
    const sortBy = url.searchParams.get('sortBy') || 'created_at';
    const sortOrder = url.searchParams.get('sortOrder') || 'DESC';
    const withRelations = url.searchParams.get('withRelations') === 'true';

    const result = await getPosts(postType, {
      page,
      limit,
      search,
      category_id: category_id ? parseInt(category_id) : null,
      sortBy,
      sortOrder,
      withRelations
    });

    return {
      success: true,
      posts: result.posts,
      total: result.pagination.total,
      totalPages: result.pagination.totalPages,
      page: result.pagination.page,
      limit: result.pagination.limit
    };
  } catch (error) {
    console.error('[Posts] Error GET posts:', error);
    return { success: false, error: error.message || 'Failed to fetch posts' };
  }
}

async function handleCreatePost(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    if (!postType) return { success: false, error: 'Post type is required' };

    const body = await request.json();
    const postData = body.post || body;
    if (!postData || Object.keys(postData).length === 0) {
      return { success: false, error: 'Post data is required' };
    }

    const post = await createPost(postType, postData);
    return { success: true, post, message: 'Post created successfully' };
  } catch (error) {
    console.error('[Posts] Error creating post:', error);
    return { success: false, error: error.message || 'Failed to create post' };
  }
}

async function handleUpdatePost(request) {
  try {
    const url = new URL(request.url);
    const body = await request.json();
    const postType = url.searchParams.get('type');
    const id = url.searchParams.get('id') || body.id;

    if (!postType) return { success: false, error: 'Post type is required' };
    if (!id) return { success: false, error: 'Post ID is required' };

    const updates = body.post || (({ id: _i, ...rest }) => rest)(body);
    if (!updates || Object.keys(updates).length === 0) {
      return { success: false, error: 'Update data is required' };
    }

    const typeConfig = getPostType(postType);

    // Handle old image cleanup
    const existing = await getPostById(postType, parseInt(id));
    if (!existing) return { success: false, error: 'Post not found' };

    const post = await updatePost(postType, parseInt(id), updates);

    // Clean up replaced images
    if (typeConfig) {
      for (const field of typeConfig.fields.filter(f => f.type === 'image')) {
        const oldKey = existing._data?.[field.name] || null;
        const newKey = updates[field.name];
        if (oldKey && newKey !== undefined && newKey !== oldKey) {
          try {
            await deleteFile(oldKey);
          } catch (err) {
            console.warn(`[Posts] Error deleting old image ${oldKey}:`, err.message);
          }
        }
      }
    }

    return { success: true, post, message: 'Post updated successfully' };
  } catch (error) {
    console.error('[Posts] Error updating post:', error);
    return { success: false, error: error.message || 'Failed to update post' };
  }
}

async function handleDeletePost(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    const id = url.searchParams.get('id');

    if (!postType) return { success: false, error: 'Post type is required' };
    if (!id) return { success: false, error: 'Post ID is required' };

    const deleted = await deletePost(postType, parseInt(id));
    if (!deleted) return { success: false, error: 'Post not found' };
    return { success: true, message: 'Post deleted successfully' };
  } catch (error) {
    console.error('[Posts] Error deleting post:', error);
    return { success: false, error: 'Failed to delete post' };
  }
}

// ============================================================================
// Image upload (admin)
// ============================================================================

async function handleUploadImage(request) {
  try {
    const formData = await request.formData();
    const file = formData.get('file');

    if (!file) return { success: false, error: 'No file provided' };

    const validation = validateUpload({
      filename: file.name,
      size: file.size,
      allowedTypes: FILE_TYPE_PRESETS.IMAGES,
      maxSize: FILE_SIZE_LIMITS.IMAGE
    });

    if (!validation.valid) {
      return { success: false, error: validation.errors.join(', ') };
    }

    const uniqueFilename = generateUniqueFilename(file.name);
    const key = generateBlogFilePath(Date.now(), uniqueFilename);
    const buffer = Buffer.from(await file.arrayBuffer());

    const uploadResult = await uploadImage({
      key,
      body: buffer,
      contentType: file.type,
      metadata: { originalName: file.name }
    });

    if (!uploadResult.success) {
      return { success: false, error: uploadResult.error || 'Upload failed' };
    }

    return { success: true, key: uploadResult.data.key };
  } catch (error) {
    console.error('[Posts] Error uploading image:', error);
    return { success: false, error: error.message || 'Upload failed' };
  }
}

// ============================================================================
// Categories (admin)
// ============================================================================

async function handleGetCategories(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    if (!postType) return { success: false, error: 'Post type is required' };

    const id = url.searchParams.get('id');
    if (id) {
      const category = await getCategoryById(postType, parseInt(id));
      if (!category) return { success: false, error: 'Category not found' };
      return { success: true, category };
    }

    const page = parseInt(url.searchParams.get('page')) || 1;
    const limit = parseInt(url.searchParams.get('limit')) || 20;
    const search = url.searchParams.get('search') || '';
    const is_active = url.searchParams.get('is_active');
    const sortBy = url.searchParams.get('sortBy') || 'title';
    const sortOrder = url.searchParams.get('sortOrder') || 'ASC';

    const result = await getCategories(postType, {
      page,
      limit,
      search,
      is_active: is_active === 'true' ? true : is_active === 'false' ? false : null,
      sortBy,
      sortOrder
    });

    return {
      success: true,
      categories: result.categories,
      total: result.pagination.total,
      totalPages: result.pagination.totalPages,
      page: result.pagination.page,
      limit: result.pagination.limit
    };
  } catch (error) {
    console.error('[Posts] Error GET categories:', error);
    return { success: false, error: error.message || 'Failed to fetch categories' };
  }
}

async function handleCreateCategory(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    if (!postType) return { success: false, error: 'Post type is required' };

    const body = await request.json();
    const categoryData = body.category || body;
    if (!categoryData || Object.keys(categoryData).length === 0) {
      return { success: false, error: 'Category data is required' };
    }

    const category = await createCategory(postType, categoryData);
    return { success: true, category, message: 'Category created successfully' };
  } catch (error) {
    console.error('[Posts] Error creating category:', error);
    return { success: false, error: error.message || 'Failed to create category' };
  }
}

async function handleUpdateCategory(request) {
  try {
    const url = new URL(request.url);
    const body = await request.json();
    const postType = url.searchParams.get('type');
    const id = url.searchParams.get('id') || body.id;

    if (!postType) return { success: false, error: 'Post type is required' };
    if (!id) return { success: false, error: 'Category ID is required' };

    const updates = body.category || (({ id: _i, ...rest }) => rest)(body);
    if (!updates || Object.keys(updates).length === 0) {
      return { success: false, error: 'Update data is required' };
    }

    const existing = await getCategoryById(postType, parseInt(id));
    if (!existing) return { success: false, error: 'Category not found' };

    const category = await updateCategory(postType, parseInt(id), updates);
    return { success: true, category, message: 'Category updated successfully' };
  } catch (error) {
    console.error('[Posts] Error updating category:', error);
    return { success: false, error: error.message || 'Failed to update category' };
  }
}

async function handleDeleteCategory(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    const id = url.searchParams.get('id');

    if (!postType) return { success: false, error: 'Post type is required' };
    if (!id) return { success: false, error: 'Category ID is required' };

    await deleteCategory(postType, parseInt(id));
    return { success: true, message: 'Category deleted successfully' };
  } catch (error) {
    console.error('[Posts] Error deleting category:', error);
    if (error.message.includes('Cannot delete')) {
      return { success: false, error: error.message };
    }
    return { success: false, error: 'Failed to delete category' };
  }
}

// ============================================================================
// Relation search (admin — used by RelationSelector picker)
// ============================================================================

async function handleSearchPosts(request) {
  try {
    const url = new URL(request.url);
    const postType = url.searchParams.get('type');
    if (!postType) return { success: false, error: 'Post type is required' };
    if (!getPostType(postType)) return { success: false, error: `Unknown post type: ${postType}` };

    const q = url.searchParams.get('q') || '';
    const limit = parseInt(url.searchParams.get('limit')) || 20;

    const posts = await searchPosts(postType, q, limit);
    return { success: true, posts };
  } catch (error) {
    console.error('[Posts] Error searching posts:', error);
    return { success: false, error: error.message || 'Failed to search posts' };
  }
}

// ============================================================================
// Public API
// ============================================================================

async function handlePublicGetConfig() {
  try {
    const config = getPostsConfig();
    return { success: true, config };
  } catch (error) {
    return { success: false, error: error.message || 'Failed to get config' };
  }
}

async function handlePublicGetPosts(request, params) {
  try {
    const postType = params?.type;
    if (!postType) return { success: false, error: 'Post type is required' };
    if (!getPostType(postType)) return { success: false, error: `Unknown post type: ${postType}` };

    const url = new URL(request.url);
    const page = parseInt(url.searchParams.get('page')) || 1;
    const limit = parseInt(url.searchParams.get('limit')) || 20;
    const category_id = url.searchParams.get('category_id') || null;
    const sortBy = url.searchParams.get('sortBy') || 'created_at';
    const sortOrder = (url.searchParams.get('sortOrder') || 'DESC').toUpperCase();
    const withRelations = url.searchParams.get('withRelations') === 'true';

    const result = await getPosts(postType, {
      page,
      limit,
      category_id: category_id ? parseInt(category_id) : null,
      sortBy,
      sortOrder,
      withRelations
    });

    return {
      success: true,
      posts: result.posts,
      total: result.pagination.total,
      totalPages: result.pagination.totalPages,
      page: result.pagination.page,
      limit: result.pagination.limit
    };
  } catch (error) {
    console.error('[Posts] Error public GET posts:', error);
    return { success: false, error: error.message || 'Failed to fetch posts' };
  }
}

async function handlePublicGetPostBySlug(request, params) {
  try {
    const postType = params?.type;
    const slug = params?.slug;
    if (!postType || !slug) return { success: false, error: 'Post type and slug are required' };

    const post = await getPostBySlug(postType, slug);
    if (!post) return { success: false, error: 'Post not found' };
    return { success: true, post };
  } catch (error) {
    console.error('[Posts] Error public GET post by slug:', error);
    return { success: false, error: error.message || 'Failed to fetch post' };
  }
}

async function handlePublicGetCategories(request, params) {
  try {
    const postType = params?.type;
    if (!postType) return { success: false, error: 'Post type is required' };

    const categories = await getActiveCategories(postType);
    return { success: true, categories };
  } catch (error) {
    console.error('[Posts] Error public GET categories:', error);
    return { success: false, error: error.message || 'Failed to fetch categories' };
  }
}

// ============================================================================
// Route Definitions
// ============================================================================

export default {
  routes: [
    // Admin config
    { path: '/admin/posts/config', method: 'GET', handler: handleGetConfig, auth: 'admin' },

    // Admin posts
    { path: '/admin/posts/posts', method: 'GET', handler: handleGetPosts, auth: 'admin' },
    { path: '/admin/posts/posts', method: 'POST', handler: handleCreatePost, auth: 'admin' },
    { path: '/admin/posts/posts', method: 'PUT', handler: handleUpdatePost, auth: 'admin' },
    { path: '/admin/posts/posts', method: 'DELETE', handler: handleDeletePost, auth: 'admin' },

    // Admin image upload
    { path: '/admin/posts/upload-image', method: 'POST', handler: handleUploadImage, auth: 'admin' },

    // Admin relation search (for RelationSelector picker)
    { path: '/admin/posts/search', method: 'GET', handler: handleSearchPosts, auth: 'admin' },

    // Admin categories
    { path: '/admin/posts/categories', method: 'GET', handler: handleGetCategories, auth: 'admin' },
    { path: '/admin/posts/categories', method: 'POST', handler: handleCreateCategory, auth: 'admin' },
    { path: '/admin/posts/categories', method: 'PUT', handler: handleUpdateCategory, auth: 'admin' },
    { path: '/admin/posts/categories', method: 'DELETE', handler: handleDeleteCategory, auth: 'admin' },

    // Public
    { path: '/posts/config', method: 'GET', handler: handlePublicGetConfig, auth: 'public' },
    { path: '/posts/:type', method: 'GET', handler: handlePublicGetPosts, auth: 'public' },
    { path: '/posts/:type/:slug', method: 'GET', handler: handlePublicGetPostBySlug, auth: 'public' },
    { path: '/posts/:type/categories', method: 'GET', handler: handlePublicGetCategories, auth: 'public' },
  ]
};