/**
 * Posts Module - Database
 * Creates zen_posts and zen_posts_category tables.
 */

import { query } from '@hykocx/zen/database';
import { getPostsConfig } from './config.js';

async function tableExists(tableName) {
  const result = await query(
    `SELECT EXISTS (
      SELECT FROM information_schema.tables
      WHERE table_schema = 'public'
      AND table_name = $1
    )`,
    [tableName]
  );
  return result.rows[0].exists;
}

async function createPostsCategoryTable() {
  const tableName = 'zen_posts_category';
  const exists = await tableExists(tableName);

  if (exists) {
    console.log(`- Table already exists: ${tableName}`);
    return { created: false, tableName };
  }

  await query(`
    CREATE TABLE zen_posts_category (
      id          SERIAL PRIMARY KEY,
      post_type   VARCHAR(100) NOT NULL,
      title       VARCHAR(255) NOT NULL,
      description TEXT,
      is_active   BOOLEAN DEFAULT true,
      created_at  TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
      updated_at  TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
    )
  `);

  await query(`CREATE INDEX idx_zen_posts_category_post_type ON zen_posts_category(post_type)`);
  await query(`CREATE INDEX idx_zen_posts_category_is_active ON zen_posts_category(is_active)`);

  console.log(`✓ Created table: ${tableName}`);
  return { created: true, tableName };
}

async function createPostsTable() {
  const tableName = 'zen_posts';
  const exists = await tableExists(tableName);

  if (exists) {
    console.log(`- Table already exists: ${tableName}`);
    return { created: false, tableName };
  }

  await query(`
    CREATE TABLE zen_posts (
      id          SERIAL PRIMARY KEY,
      post_type   VARCHAR(100) NOT NULL,
      slug        VARCHAR(500) NOT NULL,
      data        JSONB NOT NULL DEFAULT '{}',
      category_id INTEGER REFERENCES zen_posts_category(id) ON DELETE SET NULL,
      created_at  TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
      updated_at  TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
      UNIQUE(post_type, slug)
    )
  `);

  await query(`CREATE INDEX idx_zen_posts_post_type ON zen_posts(post_type)`);
  await query(`CREATE INDEX idx_zen_posts_post_type_slug ON zen_posts(post_type, slug)`);
  await query(`CREATE INDEX idx_zen_posts_category_id ON zen_posts(category_id)`);
  await query(`CREATE INDEX idx_zen_posts_data_gin ON zen_posts USING GIN (data)`);

  console.log(`✓ Created table: ${tableName}`);
  return { created: true, tableName };
}

async function createPostsRelationsTable() {
  const tableName = 'zen_posts_relations';
  const exists = await tableExists(tableName);

  if (exists) {
    console.log(`- Table already exists: ${tableName}`);
    return { created: false, tableName };
  }

  await query(`
    CREATE TABLE zen_posts_relations (
      id               SERIAL PRIMARY KEY,
      post_id          INTEGER NOT NULL REFERENCES zen_posts(id) ON DELETE CASCADE,
      field_name       VARCHAR(100) NOT NULL,
      related_post_id  INTEGER NOT NULL REFERENCES zen_posts(id) ON DELETE CASCADE,
      sort_order       INTEGER DEFAULT 0,
      UNIQUE(post_id, field_name, related_post_id)
    )
  `);

  await query(`CREATE INDEX idx_zen_posts_relations_post_id ON zen_posts_relations(post_id)`);
  await query(`CREATE INDEX idx_zen_posts_relations_related ON zen_posts_relations(related_post_id)`);

  console.log(`✓ Created table: ${tableName}`);
  return { created: true, tableName };
}

/**
 * Create all posts-related tables.
 * zen_posts_category is only created if at least one type uses the 'category' field.
 * zen_posts_relations is only created if at least one type uses the 'relation' field.
 * @returns {Promise<Object>}
 */
export async function createTables() {
  const created = [];
  const skipped = [];

  const config = getPostsConfig();
  const needsRelations = Object.values(config.types).some(t => t.hasRelations);

  // zen_posts_category must always be created before zen_posts
  // because zen_posts has a FK reference to it
  console.log('\n--- Posts Categories ---');
  const catResult = await createPostsCategoryTable();
  if (catResult.created) created.push(catResult.tableName);
  else skipped.push(catResult.tableName);

  console.log('\n--- Posts ---');
  const postResult = await createPostsTable();
  if (postResult.created) created.push(postResult.tableName);
  else skipped.push(postResult.tableName);

  if (needsRelations) {
    console.log('\n--- Posts Relations ---');
    const relResult = await createPostsRelationsTable();
    if (relResult.created) created.push(relResult.tableName);
    else skipped.push(relResult.tableName);
  }

  return { created, skipped };
}