-- tests/backup_test.lua
-- Тестирование бэкапов и восстановления

local function setup_backup_test()
    print("=== Setup Backup Test ===")
    
    db.execute("CREATE DATABASE IF NOT EXISTS backup_test")
    db.execute("USE backup_test")
    
    db.execute([[
        CREATE COLLECTION IF NOT EXISTS users
    ]])
    
    -- Вставляем тестовые данные
    for i = 1, 100 do
        db.execute(string.format([[
            INSERT INTO users VALUES {
                _id = "user_%d",
                name = "User %d",
                email = "user%d@test.com",
                score = %d,
                created_at = %d
            }
        ]], i, i, i, math.random(1, 1000), os.time() * 1000))
    end
    
    print("Inserted 100 test documents")
    
    -- Включаем планировщик бэкапов
    db.execute([[
        SET BACKUP SCHEDULE daily_backup
        WITH CRON "0 0 * * *"
        TYPE full
        RETENTION 7
    ]])
    
    return true
end

local function test_full_backup()
    print("\n=== Test 1: Full Backup ===")
    
    -- Запускаем полный бэкап
    local result = db.execute("BACKUP DATABASE backup_test TO full_backup.msgpack")
    print("Backup result: " .. tostring(result))
    
    -- Проверяем, что файл бэкапа создан
    local backup_info = db.execute("SHOW BACKUP INFO")
    local info = db.json_decode(backup_info)
    
    print(string.format("Backup ID: %s", info.id or "unknown"))
    print(string.format("Backup size: %d bytes", info.size_bytes or 0))
    print(string.format("Backup time: %s", info.end_time or "unknown"))
    
    if info.id and info.size_bytes > 0 then
        print("✅ Full backup completed successfully")
        return info.id
    else
        print("❌ Full backup failed")
        return nil
    end
end

local function test_incremental_backup()
    print("\n=== Test 2: Incremental Backup ===")
    
    -- Добавляем новые документы после полного бэкапа
    for i = 101, 150 do
        db.execute(string.format([[
            INSERT INTO users VALUES {
                _id = "user_%d",
                name = "New User %d",
                email = "newuser%d@test.com",
                score = %d,
                created_at = %d
            }
        ]], i, i, i, math.random(1, 1000), os.time() * 1000))
    end
    
    print("Added 50 new documents")
    
    -- Запускаем инкрементальный бэкап
    local result = db.execute("BACKUP DATABASE backup_test INCREMENTAL TO inc_backup.msgpack")
    print("Incremental backup result: " .. tostring(result))
    
    local backup_info = db.execute("SHOW BACKUP INFO inc_backup")
    local info = db.json_decode(backup_info)
    
    if info and info.type == "incremental" then
        print(string.format("Incremental backup: %d entries", info.entries_count or 0))
        print("✅ Incremental backup completed successfully")
        return true
    else
        print("❌ Incremental backup failed")
        return false
    end
end

local function test_backup_restore()
    print("\n=== Test 3: Backup Restore ===")
    
    -- Создаём новую БД для восстановления
    db.execute("CREATE DATABASE IF NOT EXISTS restore_test")
    
    -- Восстанавливаем из полного бэкапа
    local result = db.execute("RESTORE DATABASE restore_test FROM full_backup.msgpack")
    print("Restore result: " .. tostring(result))
    
    -- Проверяем количество документов
    db.execute("USE restore_test")
    local count = db.execute("SELECT COUNT(*) FROM users")
    local count_data = db.json_decode(count)
    
    print(string.format("Restored documents: %d", count_data[1].count or 0))
    
    if count_data[1].count == 100 then
        print("✅ Full restore successful")
        return true
    else
        print("❌ Restore failed: expected 100 documents")
        return false
    end
end

local function test_incremental_restore()
    print("\n=== Test 4: Incremental Restore ===")
    
    -- Создаём другую БД для теста инкрементального восстановления
    db.execute("CREATE DATABASE IF NOT EXISTS inc_restore_test")
    
    -- Восстанавливаем сначала полный бэкап
    db.execute("USE inc_restore_test")
    db.execute("RESTORE DATABASE inc_restore_test FROM full_backup.msgpack")
    
    local before_count = db.execute("SELECT COUNT(*) FROM users")
    local before_data = db.json_decode(before_count)
    print(string.format("After full restore: %d documents", before_data[1].count or 0))
    
    -- Затем применяем инкрементальный
    db.execute("RESTORE DATABASE inc_restore_test INCREMENTAL FROM inc_backup.msgpack")
    
    local after_count = db.execute("SELECT COUNT(*) FROM users")
    local after_data = db.json_decode(after_count)
    print(string.format("After incremental restore: %d documents", after_data[1].count or 0))
    
    if after_data[1].count == 150 then
        print("✅ Incremental restore successful")
        return true
    else
        print(string.format("❌ Expected 150 documents, got %d", after_data[1].count or 0))
        return false
    end
end

local function test_backup_schedule()
    print("\n=== Test 5: Backup Schedule ===")
    
    local schedules = db.execute("SHOW BACKUP SCHEDULES")
    local schedules_data = db.json_decode(schedules)
    
    print("Current backup schedules:")
    for _, schedule in ipairs(schedules_data) do
        print(string.format("  %s: cron='%s', type='%s', enabled=%s",
            schedule.name, schedule.cron_expr, schedule.type, tostring(schedule.enabled)))
    end
    
    if #schedules_data > 0 then
        print("✅ Backup schedules configured correctly")
        return true
    else
        print("⚠️ No backup schedules found")
        return false
    end
end

local function test_backup_compression()
    print("\n=== Test 6: Backup Compression ===")
    
    -- Включаем сжатие
    db.execute("SET BACKUP COMPRESSION true")
    
    -- Создаём много данных для бэкапа
    for i = 1, 1000 do
        db.execute(string.format([[
            INSERT INTO users VALUES {
                _id = "compress_%d",
                data = "%s"
            }
        ]], i, string.rep("x", 1000)))
    end
    
    local start_time = os.clock()
    db.execute("BACKUP DATABASE backup_test TO compressed_backup.msgpack WITH COMPRESSION")
    local duration = os.clock() - start_time
    
    local backup_info = db.execute("SHOW BACKUP INFO compressed_backup")
    local info = db.json_decode(backup_info)
    
    print(string.format("Compressed backup size: %d bytes", info.size_bytes or 0))
    print(string.format("Compression time: %.2fs", duration))
    
    if info.size_bytes and info.size_bytes > 0 then
        print("✅ Backup compression working")
        return true
    else
        print("❌ Backup compression failed")
        return false
    end
end

local function test_backup_retention()
    print("\n=== Test 7: Backup Retention ===")
    
    -- Создаём несколько старых бэкапов (симуляция)
    for i = 1, 10 do
        db.execute(string.format("BACKUP DATABASE backup_test TO old_backup_%d.msgpack", i))
    end
    
    -- Устанавливаем retention на 5 дней
    db.execute("SET BACKUP RETENTION 5")
    
    -- Запускаем очистку
    db.execute("CLEANUP BACKUPS")
    
    local backups = db.execute("SHOW BACKUPS")
    local backups_data = db.json_decode(backups)
    
    print(string.format("Remaining backups after cleanup: %d", #backups_data))
    
    -- Проверяем, что не все бэкапы удалены
    if #backups_data > 0 then
        print("✅ Backup retention working")
        return true
    else
        print("⚠️ All backups cleaned up, retention may be too aggressive")
        return false
    end
end

local function test_backup_verify()
    print("\n=== Test 8: Backup Verification ===")
    
    -- Проверяем целостность бэкапа
    local result = db.execute("VERIFY BACKUP full_backup.msgpack")
    local verify_result = db.json_decode(result)
    
    print(string.format("Verification result: %s", verify_result.valid and "VALID" or "INVALID"))
    print(string.format("Checksum match: %s", tostring(verify_result.checksum_match)))
    print(string.format("Corruption detected: %s", tostring(verify_result.corrupted)))
    
    if verify_result.valid then
        print("✅ Backup verification passed")
        return true
    else
        print("❌ Backup verification failed")
        return false
    end
end

local function test_backup_parallel()
    print("\n=== Test 9: Parallel Backups ===")
    
    -- Проверяем, что параллельные бэкапы блокируются
    local results = {}
    
    local function run_backup(name)
        local success, err = pcall(function()
            return db.execute(string.format("BACKUP DATABASE backup_test TO parallel_%s.msgpack", name))
        end)
        return success
    end
    
    -- Запускаем 3 параллельных бэкапа
    local threads = {}
    for i = 1, 3 do
        table.insert(threads, coroutine.create(function()
            local result = run_backup(tostring(i))
            coroutine.yield(result)
        end))
    end
    
    for _, thread in ipairs(threads) do
        coroutine.resume(thread)
    end
    
    local success_count = 0
    for _, thread in ipairs(threads) do
        local success = coroutine.resume(thread)
        if success then success_count = success_count + 1 end
    end
    
    print(string.format("Parallel backups completed: %d/3 succeeded", success_count))
    
    if success_count == 1 then
        print("✅ Parallel backups correctly limited to 1")
        return true
    else
        print("⚠️ Parallel backup behavior may need tuning")
        return false
    end
end

local function cleanup_backup()
    print("\n=== Cleanup ===")
    db.execute("DROP DATABASE IF EXISTS backup_test")
    db.execute("DROP DATABASE IF EXISTS restore_test")
    db.execute("DROP DATABASE IF EXISTS inc_restore_test")
    print("Cleanup completed")
end

local function run_all_backup_tests()
    print("╔══════════════════════════════════════════════════════════════╗")
    print("║     BACKUP TESTS SUITE                                        ║")
    print("╚══════════════════════════════════════════════════════════════╝")
    
    setup_backup_test()
    
    local full_backup_id = test_full_backup()
    local results = {
        full_backup_id ~= nil,
        test_incremental_backup(),
        test_backup_restore(),
        test_incremental_restore(),
        test_backup_schedule(),
        test_backup_compression(),
        test_backup_retention(),
        test_backup_verify(),
        test_backup_parallel()
    }
    
    print("\n╔══════════════════════════════════════════════════════════════╗")
    print("║                     TEST RESULTS                              ║")
    print("╚══════════════════════════════════════════════════════════════╝")
    
    local passed = 0
    for i, result in ipairs(results) do
        local status = result and "✅ PASSED" or "⚠️ SKIPPED/FAILED"
        print(string.format("Test %d: %s", i, status))
        if result then passed = passed + 1 end
    end
    
    print(string.format("\nTotal: %d/%d tests passed", passed, #results))
    
    cleanup_backup()
    
    return passed == #results
end

return run_all_backup_tests()