/**
 * MCP Outline PostgreSQL - Templates Tools
 * Templates are documents with template=true
 * @author Descomplicar® | @link descomplicar.pt | @copyright 2026
 */

import { Pool } from 'pg';
import { BaseTool, ToolResponse, PaginationArgs } from '../types/tools.js';
import { validatePagination, isValidUUID, sanitizeInput } from '../utils/security.js';

interface TemplateListArgs extends PaginationArgs {
  collection_id?: string;
}

/**
 * templates.list - List templates
 */
const listTemplates: BaseTool<TemplateListArgs> = {
  name: 'outline_list_templates',
  description: 'List document templates. Templates are reusable document structures.',
  inputSchema: {
    type: 'object',
    properties: {
      collection_id: { type: 'string', description: 'Filter by collection ID (UUID)' },
      limit: { type: 'number', description: 'Max results (default: 25)' },
      offset: { type: 'number', description: 'Skip results (default: 0)' },
    },
  },
  handler: async (args, pgClient): Promise<ToolResponse> => {
    const { limit, offset } = validatePagination(args.limit, args.offset);
    const conditions: string[] = ['d.template = true', 'd."deletedAt" IS NULL'];
    const params: any[] = [];
    let idx = 1;

    if (args.collection_id) {
      if (!isValidUUID(args.collection_id)) throw new Error('Invalid collection_id');
      conditions.push(`d."collectionId" = $${idx++}`);
      params.push(args.collection_id);
    }

    const result = await pgClient.query(`
      SELECT
        d.id, d.title, d.icon, d."collectionId", d."createdById",
        d."createdAt", d."updatedAt",
        c.name as "collectionName",
        u.name as "createdByName",
        (SELECT COUNT(*) FROM documents WHERE "templateId" = d.id) as "usageCount"
      FROM documents d
      LEFT JOIN collections c ON d."collectionId" = c.id
      LEFT JOIN users u ON d."createdById" = u.id
      WHERE ${conditions.join(' AND ')}
      ORDER BY d."updatedAt" DESC
      LIMIT $${idx++} OFFSET $${idx}
    `, [...params, limit, offset]);

    return {
      content: [{ type: 'text', text: JSON.stringify({ data: result.rows, pagination: { limit, offset, total: result.rows.length } }, null, 2) }],
    };
  },
};

/**
 * templates.info - Get template details
 */
const getTemplate: BaseTool<{ id: string }> = {
  name: 'outline_get_template',
  description: 'Get detailed information about a template including its content.',
  inputSchema: {
    type: 'object',
    properties: {
      id: { type: 'string', description: 'Template ID (UUID)' },
    },
    required: ['id'],
  },
  handler: async (args, pgClient): Promise<ToolResponse> => {
    if (!isValidUUID(args.id)) throw new Error('Invalid template ID');

    const result = await pgClient.query(`
      SELECT
        d.*, c.name as "collectionName", u.name as "createdByName",
        (SELECT COUNT(*) FROM documents WHERE "templateId" = d.id) as "usageCount"
      FROM documents d
      LEFT JOIN collections c ON d."collectionId" = c.id
      LEFT JOIN users u ON d."createdById" = u.id
      WHERE d.id = $1 AND d.template = true AND d."deletedAt" IS NULL
    `, [args.id]);

    if (result.rows.length === 0) throw new Error('Template not found');

    return {
      content: [{ type: 'text', text: JSON.stringify({ data: result.rows[0] }, null, 2) }],
    };
  },
};

/**
 * templates.create - Create document from template
 */
const createFromTemplate: BaseTool<{ template_id: string; title: string; collection_id?: string; parent_document_id?: string }> = {
  name: 'outline_create_from_template',
  description: 'Create a new document from a template.',
  inputSchema: {
    type: 'object',
    properties: {
      template_id: { type: 'string', description: 'Template ID (UUID)' },
      title: { type: 'string', description: 'Title for the new document' },
      collection_id: { type: 'string', description: 'Collection ID (UUID, optional - uses template collection)' },
      parent_document_id: { type: 'string', description: 'Parent document ID (UUID, optional)' },
    },
    required: ['template_id', 'title'],
  },
  handler: async (args, pgClient): Promise<ToolResponse> => {
    if (!isValidUUID(args.template_id)) throw new Error('Invalid template_id');
    if (args.collection_id && !isValidUUID(args.collection_id)) throw new Error('Invalid collection_id');
    if (args.parent_document_id && !isValidUUID(args.parent_document_id)) throw new Error('Invalid parent_document_id');

    // Get template
    const template = await pgClient.query(
      `SELECT * FROM documents WHERE id = $1 AND template = true AND "deletedAt" IS NULL`,
      [args.template_id]
    );

    if (template.rows.length === 0) throw new Error('Template not found');

    const t = template.rows[0];

    // Get user
    const user = await pgClient.query(`SELECT id FROM users WHERE role = 'admin' AND "deletedAt" IS NULL LIMIT 1`);
    const userId = user.rows.length > 0 ? user.rows[0].id : t.createdById;

    // Create document from template
    const result = await pgClient.query(`
      INSERT INTO documents (
        id, title, text, icon, "collectionId", "teamId", "parentDocumentId",
        "templateId", "createdById", "lastModifiedById", template,
        "createdAt", "updatedAt"
      )
      VALUES (
        gen_random_uuid(), $1, $2, $3, $4, $5, $6, $7, $8, $8, false, NOW(), NOW()
      )
      RETURNING *
    `, [
      sanitizeInput(args.title),
      t.text,
      t.icon,
      args.collection_id || t.collectionId,
      t.teamId,
      args.parent_document_id || null,
      args.template_id,
      userId,
    ]);

    return {
      content: [{ type: 'text', text: JSON.stringify({ data: result.rows[0], message: 'Document created from template' }, null, 2) }],
    };
  },
};

/**
 * templates.convert - Convert document to template
 */
const convertToTemplate: BaseTool<{ document_id: string }> = {
  name: 'outline_convert_to_template',
  description: 'Convert an existing document to a template.',
  inputSchema: {
    type: 'object',
    properties: {
      document_id: { type: 'string', description: 'Document ID to convert (UUID)' },
    },
    required: ['document_id'],
  },
  handler: async (args, pgClient): Promise<ToolResponse> => {
    if (!isValidUUID(args.document_id)) throw new Error('Invalid document_id');

    const result = await pgClient.query(`
      UPDATE documents
      SET template = true, "updatedAt" = NOW()
      WHERE id = $1 AND "deletedAt" IS NULL AND template = false
      RETURNING id, title, template
    `, [args.document_id]);

    if (result.rows.length === 0) throw new Error('Document not found or already a template');

    return {
      content: [{ type: 'text', text: JSON.stringify({ data: result.rows[0], message: 'Converted to template' }, null, 2) }],
    };
  },
};

/**
 * templates.unconvert - Convert template back to document
 */
const convertFromTemplate: BaseTool<{ template_id: string }> = {
  name: 'outline_convert_from_template',
  description: 'Convert a template back to a regular document.',
  inputSchema: {
    type: 'object',
    properties: {
      template_id: { type: 'string', description: 'Template ID to convert (UUID)' },
    },
    required: ['template_id'],
  },
  handler: async (args, pgClient): Promise<ToolResponse> => {
    if (!isValidUUID(args.template_id)) throw new Error('Invalid template_id');

    const result = await pgClient.query(`
      UPDATE documents
      SET template = false, "updatedAt" = NOW()
      WHERE id = $1 AND "deletedAt" IS NULL AND template = true
      RETURNING id, title, template
    `, [args.template_id]);

    if (result.rows.length === 0) throw new Error('Template not found or already a document');

    return {
      content: [{ type: 'text', text: JSON.stringify({ data: result.rows[0], message: 'Converted to document' }, null, 2) }],
    };
  },
};

export const templatesTools: BaseTool<any>[] = [
  listTemplates, getTemplate, createFromTemplate, convertToTemplate, convertFromTemplate
];