/**
 * @param { import("knex").Knex } knex
 * @returns { Promise<void> }
 */
exports.up = async function(knex) {
  // Guarded: with transaction:false a failure after this CREATE (e.g. in the
  // Citus distribution below) leaves the table behind on retry.
  if (!(await knex.schema.hasTable('asset_facts'))) {
  await knex.schema.createTable('asset_facts', (table) => {
    table.uuid('tenant').notNullable().references('tenant').inTable('tenants');
    table.uuid('asset_fact_id').defaultTo(knex.raw('gen_random_uuid()')).notNullable();
    table.uuid('asset_id').notNullable();
    table.text('source_type').notNullable();
    table.text('provider').nullable();
    table.uuid('integration_id').nullable();
    table.text('namespace').notNullable();
    table.text('fact_key').notNullable();
    table.text('label').notNullable();
    table.text('value_text').nullable();
    table.decimal('value_number', 12, 4).nullable();
    table.boolean('value_bool').nullable();
    table.jsonb('value_json').notNullable().defaultTo(knex.raw(`'{}'::jsonb`));
    table.text('source').notNullable();
    table.timestamp('source_updated_at', { useTz: true }).nullable();
    table.timestamp('last_synced_at', { useTz: true }).nullable();
    table.boolean('is_available').notNullable().defaultTo(true);
    table.timestamp('created_at', { useTz: true }).notNullable().defaultTo(knex.fn.now());
    table.timestamp('updated_at', { useTz: true }).notNullable().defaultTo(knex.fn.now());

    table.primary(['tenant', 'asset_fact_id']);
    table.foreign(['tenant', 'asset_id']).references(['tenant', 'asset_id']).inTable('assets').onDelete('CASCADE');
    table.index(['tenant', 'asset_id'], 'asset_facts_tenant_asset_idx');
    table.unique(['tenant', 'asset_id', 'source_type', 'namespace', 'fact_key'], 'asset_facts_tenant_asset_fact_current_uk');
  });
  }

  const citusEnabled = await knex.raw(`
    SELECT EXISTS (
      SELECT 1
      FROM pg_extension
      WHERE extname = 'citus'
    ) AS enabled;
  `);

  if (citusEnabled.rows?.[0]?.enabled) {
    // asset_facts colocates with assets, which fresh Citus chains never
    // distributed. No-op on clusters that already have it.
    const assetsDistributed = await knex.raw(`
      SELECT EXISTS (
        SELECT 1
        FROM pg_dist_partition
        WHERE logicalrelid = 'assets'::regclass
      ) AS is_distributed;
    `);
    if (!assetsDistributed.rows?.[0]?.is_distributed) {
      await knex.raw("SELECT create_distributed_table('assets', 'tenant')");
    }

    const alreadyDistributed = await knex.raw(`
      SELECT EXISTS (
        SELECT 1
        FROM pg_dist_partition
        WHERE logicalrelid = 'asset_facts'::regclass
      ) AS is_distributed;
    `);

    if (!alreadyDistributed.rows?.[0]?.is_distributed) {
      await knex.raw("SELECT create_distributed_table('asset_facts', 'tenant', colocate_with => 'assets')");
    }
  } else {
    console.warn('[create_asset_facts_table] Skipping create_distributed_table (Citus extension unavailable)');
  }
};

/**
 * @param { import("knex").Knex } knex
 * @returns { Promise<void> }
 */
exports.down = async function(knex) {
  await knex.schema.dropTableIfExists('asset_facts');
};

// create_distributed_table cannot run inside a transaction block.
exports.config = { transaction: false };