import { query } from "./db-client";
import { getTableConfig } from "./table-config";

export async function ensureFinanceTables(): Promise<void> {
  try {
    // Overrides tables
    await query(`
      CREATE TABLE IF NOT EXISTS income_category_overrides (
        record_id TEXT PRIMARY KEY,
        category_id TEXT NOT NULL,
        created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
      )
    `);
    await query(`
      CREATE TABLE IF NOT EXISTS expense_category_overrides (
        record_id TEXT PRIMARY KEY,
        category_id TEXT NOT NULL,
        created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
      )
    `);

    // Tags tables
    await query(`
      CREATE TABLE IF NOT EXISTS node_tags (
        id SERIAL PRIMARY KEY,
        name TEXT NOT NULL,
        color TEXT NOT NULL DEFAULT '#2563eb'
      )
    `);
    await query(`
      CREATE TABLE IF NOT EXISTS node_tag_assignments (
        id SERIAL PRIMARY KEY,
        node_id TEXT NOT NULL,
        tag_id INTEGER NOT NULL REFERENCES node_tags(id) ON DELETE CASCADE,
        context TEXT NOT NULL DEFAULT 'income',
        UNIQUE(node_id, tag_id, context)
      )
    `);
  } catch (err) {
    console.error("[FINANCE] Failed to ensure metadata tables:", err);
  }
}

async function tableExists(tableName: string): Promise<boolean> {
  try {
    const result = await query(
      `SELECT EXISTS (
        SELECT FROM information_schema.tables
        WHERE table_schema = 'public' AND table_name = $1
      ) as exists`,
      [tableName]
    );
    return result.rows[0]?.exists === true;
  } catch {
    return false;
  }
}

export async function ensureViews(): Promise<void> {
  const config = getTableConfig();
  try {
    const incomeExists = await tableExists(config.incomeTable);
    const expenseExists = await tableExists(config.expenseTable);

    if (!incomeExists && !expenseExists) {
      return;
    }

    if (incomeExists) {
      // CREATE OR REPLACE VIEW не умеет менять типы столбцов (тип stavkands в источнике
      // изменился text ↔ varchar) — пересоздаём view целиком. Зависимых объектов нет.
      await query(`DROP VIEW IF EXISTS vw_income_effective`);
      await query(`
        CREATE VIEW vw_income_effective AS
        SELECT t.*, o.category_id as _override_category_id
        FROM "${config.incomeTable}" t
        LEFT JOIN income_category_overrides o ON o.record_id = t.id::text
      `);
    }

    if (expenseExists) {
      await query(`DROP VIEW IF EXISTS vw_expense_effective`);
      await query(`
        CREATE VIEW vw_expense_effective AS
        SELECT t.*, o.category_id as _override_category_id
        FROM "${config.expenseTable}" t
        LEFT JOIN expense_category_overrides o ON o.record_id = t.id::text
      `);
    }
  } catch (err) {
    console.error("[FINANCE] Failed to create views:", err);
  }
}