const pool = require("../db/pool.js");
const { DeleteObjectCommand } = require("@aws-sdk/client-s3");
const onPremiseClient = require('../config/onPremiseClient.js');
const cloudClient = require('../config/cloudClient.js');
const storageClients = {
    'ONPREMISE': onPremiseClient,
    'CLOUD': cloudClient
};
const s3 = storageClients[process.env.DEPLOYMENT_TYPE || 'ONPREMISE'];
const env = process.env.NODE_ENV;
const tbData = env === 'production' ? 'tb_data' : '_test_tb_data';

async function runAutoClean() {
    const client = await pool.connect();
    try {
        console.log("⏰ Running auto clean batch job...");
        
        // 1. 글로벌 보관 정책 조회
        const policyRes = await client.query("SELECT * FROM ver4.tb_system_policy WHERE policy_key = 'GLOBAL_DELETE_POLICY'");
        if (policyRes.rows.length === 0 || !policyRes.rows[0].is_active) {
            console.log("⏰ Auto clean policy is disabled or not found.");
            return;
        }

        const { limit_file_count, limit_days } = policyRes.rows[0];

        // 2. 삭제 대상 파일 검색 (각 현장의 파일 개수가 limit_file_count 미만이고, limit_days 일이 지난 파일)
        const targetQuery = `
            SELECT data_id, project_id, object_key, preview_key, popup_key, thumbnail_key, 
                   path1, path2, path3, path4, path5, path6, path7, path8, data_depth, is_folder
            FROM ver4.${tbData}
            WHERE is_folder = false AND is_removed = false
              AND project_id IN (
                  SELECT project_id 
                  FROM ver4.${tbData} 
                  WHERE is_folder = false AND is_removed = false
                  GROUP BY project_id 
                  HAVING COUNT(*) < $1
              )
              AND create_date < NOW() - CAST($2 || ' days' AS INTERVAL);
        `;
        const targets = await client.query(targetQuery, [limit_file_count, limit_days]);

        console.log(`⏰ Found ${targets.rows.length} files to clean up.`);

        for (const file of targets.rows) {
            let success = true;
            let keysToDelete = [];
            if (file.object_key) keysToDelete.push(file.object_key);
            if (file.preview_key) keysToDelete.push(file.preview_key);
            if (file.popup_key) keysToDelete.push(file.popup_key);
            if (file.thumbnail_key) keysToDelete.push(file.thumbnail_key);

            // S3 실물 파일 삭제
            for (const key of keysToDelete) {
                try {
                    const command = new DeleteObjectCommand({
                        Bucket: file.project_id, // 현장 ID를 버킷 명으로 사용함
                        Key: key
                    });
                    await s3.send(command);
                } catch (s3Err) {
                    console.error(`❌ S3 Delete Error [Key: ${key}]:`, s3Err.message);
                    success = false;
                }
            }

            // DB 메타 정보 완전 제거
            try {
                await client.query(`DELETE FROM ver4.${tbData} WHERE data_id = $1`, [file.data_id]);
            } catch (dbErr) {
                console.error(`❌ DB Delete Error [DataID: ${file.data_id}]:`, dbErr.message);
                success = false;
            }

            // 삭제 경로 조합
            let cleanPath = '';
            for (let i = 1; i <= file.data_depth; i++) {
                if (file[`path${i}`]) cleanPath += '/' + file[`path${i}`];
            }

            // 로그 기록
            const criteria = `보관수량 ${limit_file_count}개 미만 / 기한 ${limit_days}일 경과`;
            await client.query(`
                INSERT INTO ver4.tb_auto_clean_log (clean_date, project_id, clean_path, criteria_info, result_status)
                VALUES (CURRENT_TIMESTAMP, 'SYSTEM', $1, $2, $3);
            `, [cleanPath, criteria, success ? 'SUCCESS' : 'FAILED']);
        }
        console.log("⏰ Auto clean batch job finished successfully.");
    } catch (err) {
        console.error("❌ Auto Clean Batch Error:", err);
    } finally {
        client.release();
    }
}

// 매일 자정에 한 번 가동하는 타이머 등록 함수
function startScheduler() {
    const now = new Date();
    const target = new Date();
    target.setHours(0, 0, 0, 0);
    if (now > target) {
        target.setDate(target.getDate() + 1);
    }
    const delay = target - now;

    console.log(`⏰ Scheduler loaded. Next run in ${Math.floor(delay / 1000 / 60)} minutes.`);
    setTimeout(async () => {
        await runAutoClean();
        // 실행 후 다음날 자정으로 다시 예약
        startScheduler();
    }, delay);
}

module.exports = {
    start: startScheduler,
    runNow: runAutoClean
};