"use strict";

/*
 * バックアップパイプライン全体(pg_dump→分割→アップロード→ローテーション→ログ)を
 * 本番DBに触れずに試せるよう、テスト用DBを作成・削除するヘルパー。
 * PGHOST/PGPORT/PGUSER/PGPASSWORD は通常バックアップと同じ接続情報を再利用する。
 */

const { spawn } = require("child_process");

function runCommand(bin, args, env) {
    return new Promise((resolve, reject) => {
        const child = spawn(bin, args, { env, stdio: ["ignore", "pipe", "pipe"] });
        let stdout = "";
        let stderr = "";

        child.stdout.on("data", (d) => (stdout += d.toString("utf8")));
        child.stderr.on("data", (d) => (stderr += d.toString("utf8")));

        child.on("error", (err) => reject(new Error(`${bin} 起動失敗: ${err.message}`)));
        child.on("close", (code) => {
            if (code !== 0) {
                reject(new Error(`${bin} 異常終了 (code=${code}): ${(stderr || stdout).trim()}`));
                return;
            }
            resolve({ stdout: stdout.trim(), stderr: stderr.trim() });
        });
    });
}

function buildEnv() {
    const env = { ...process.env };
    if (process.env.PGPASSWORD) {
        env.PGPASSWORD = process.env.PGPASSWORD;
    }
    return env;
}

function connectionInfo() {
    return {
        host: process.env.PGHOST || "localhost",
        port: process.env.PGPORT || "5432",
        user: process.env.PGUSER || "postgres",
    };
}

async function createTestDb(dbName) {
    const bin = process.env.PG_CREATEDB_BIN || "createdb";
    const { host, port, user } = connectionInfo();

    console.log(`テスト用DB作成: ${dbName} (host=${host} port=${port} user=${user})`);
    try {
        await runCommand(bin, ["-h", host, "-p", String(port), "-U", user, dbName], buildEnv());
        console.log(`テスト用DB作成完了: ${dbName}`);
    } catch (err) {
        console.error(`テスト用DB作成失敗: ${err.message}`);
        console.error(`既に存在する場合は先に 'node backup.js drop-test-db ${dbName}' を実行してください。`);
        throw err;
    }
}

async function dropTestDb(dbName) {
    const bin = process.env.PG_DROPDB_BIN || "dropdb";
    const { host, port, user } = connectionInfo();

    console.log(`テスト用DB削除: ${dbName} (host=${host} port=${port} user=${user})`);
    await runCommand(bin, ["-h", host, "-p", String(port), "-U", user, "--if-exists", dbName], buildEnv());
    console.log(`テスト用DB削除完了: ${dbName}`);
}

// restore.js が使う汎用版(任意のDB名に対して作成・削除)。
// dropDatabase は既定で --if-exists を付けない(復元対象DBが本当に存在するか厳密に確認するため)。
async function createDatabase(dbName) {
    const bin = process.env.PG_CREATEDB_BIN || "createdb";
    const { host, port, user } = connectionInfo();

    await runCommand(bin, ["-h", host, "-p", String(port), "-U", user, dbName], buildEnv());
}

async function dropDatabase(dbName, { ifExists = false } = {}) {
    const bin = process.env.PG_DROPDB_BIN || "dropdb";
    const { host, port, user } = connectionInfo();

    const args = ["-h", host, "-p", String(port), "-U", user];
    if (ifExists) args.push("--if-exists");
    args.push(dbName);

    await runCommand(bin, args, buildEnv());
}

module.exports = { createTestDb, dropTestDb, createDatabase, dropDatabase };