package store

import (
	"errors"
	"fmt"
	"sync"
	"testing"
	"time"

	"github.com/glebarez/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/wangjia/pay/internal/model"
)

func seedPaid(t *testing.T, os *OrderStore, outNo string, amount int64) {
	t.Helper()
	if err := os.CreateOrder(&model.OrderV2{
		OutTradeNo: outNo, BizSystem: "pangolin", BizCode: "pro_year",
		AmountMinor: amount, Currency: "CNY", Status: model.OrderPaidV2,
	}); err != nil {
		t.Fatal(err)
	}
	if err := os.CreateAttempt(&model.Attempt{
		OutTradeNo: outNo, Channel: "alipay", ProviderRef: outNo,
		AmountMinor: amount, Currency: "CNY", Status: model.AttemptPaid,
	}); err != nil {
		t.Fatal(err)
	}
}

func TestRefundStoreLifecycle(t *testing.T) {
	db := model.OpenTestDB(t)
	os := NewOrderStore(db)
	rs := NewRefundStore(db)
	seedPaid(t, os, "PAY-1", 19900)

	// PaidAttempt 定位原交易
	att, err := os.PaidAttempt("PAY-1")
	if err != nil || att.Channel != "alipay" || att.ProviderRef != "PAY-1" {
		t.Fatalf("PaidAttempt = %+v, %v", att, err)
	}

	// 建两笔部分退款(processing)
	for _, id := range []string{"rf-1", "rf-2"} {
		if err := rs.CreateRefund(&model.Refund{
			RefundID: id, OutTradeNo: "PAY-1", AttemptProviderRef: "PAY-1",
			AmountMinor: 5000, Currency: "CNY", Status: model.RefundProcessing, InitiatedBy: "business",
		}); err != nil {
			t.Fatal(err)
		}
	}
	// 非失败之和 = 10000(占额度)
	if sum, _ := rs.RefundSum("PAY-1", model.RefundRequested, model.RefundProcessing, model.RefundManualPending, model.RefundSucceeded); sum != 10000 {
		t.Fatalf("reserved sum = %d want 10000", sum)
	}

	// rf-1 翻 succeeded(条件正确)
	ok, err := rs.MarkRefundStatus("rf-1", model.RefundProcessing, model.RefundSucceeded, "ali-refund-1", time.Now())
	if err != nil || !ok {
		t.Fatalf("mark rf-1 = %v, %v", ok, err)
	}
	// 再翻一次(from 已不符)→ no-op
	if ok, _ := rs.MarkRefundStatus("rf-1", model.RefundProcessing, model.RefundSucceeded, "x", time.Now()); ok {
		t.Fatal("重复翻转应 no-op")
	}
	r1, _ := rs.GetRefund("rf-1")
	if r1.Status != model.RefundSucceeded || r1.ProviderRefundRef != "ali-refund-1" || r1.CompletedAt == nil {
		t.Fatalf("rf-1 = %+v", r1)
	}

	// 部分退:succeeded 之和 5000 < 19900 → partially_refunded
	succ, _ := rs.RefundSum("PAY-1", model.RefundSucceeded)
	if flipped, _ := os.ApplyRefundToOrder("PAY-1", succ >= 19900); !flipped {
		t.Fatal("ApplyRefundToOrder 应翻转")
	}
	if o, _ := os.GetOrder("PAY-1"); o.Status != model.OrderPartRefundedV2 {
		t.Fatalf("order status = %s want partially_refunded", o.Status)
	}

	// rf-2 也成功 → 总退 10000 仍 < 19900,保持 partially_refunded(非 fully)
	_, _ = rs.MarkRefundStatus("rf-2", model.RefundProcessing, model.RefundSucceeded, "ali-refund-2", time.Now())
	succ, _ = rs.RefundSum("PAY-1", model.RefundSucceeded)
	_, _ = os.ApplyRefundToOrder("PAY-1", succ >= 19900)
	if o, _ := os.GetOrder("PAY-1"); o.Status != model.OrderPartRefundedV2 {
		t.Fatalf("order status = %s want partially_refunded", o.Status)
	}
}

func TestApplyRefundToOrderFully(t *testing.T) {
	db := model.OpenTestDB(t)
	os := NewOrderStore(db)
	seedPaid(t, os, "PAY-2", 10000)
	if _, err := os.ApplyRefundToOrder("PAY-2", true); err != nil {
		t.Fatal(err)
	}
	if o, _ := os.GetOrder("PAY-2"); o.Status != model.OrderRefundedV2 {
		t.Fatalf("status = %s want refunded", o.Status)
	}
}

func TestListManualPending(t *testing.T) {
	db := model.OpenTestDB(t)
	rs := NewRefundStore(db)
	_ = rs.CreateRefund(&model.Refund{RefundID: "rf-m1", OutTradeNo: "C-1", AmountMinor: 1, Currency: "USDT", Status: model.RefundManualPending})
	_ = rs.CreateRefund(&model.Refund{RefundID: "rf-p1", OutTradeNo: "C-2", AmountMinor: 1, Currency: "USDT", Status: model.RefundProcessing})
	list, err := rs.ListManualPending(50)
	if err != nil || len(list) != 1 || list[0].RefundID != "rf-m1" {
		t.Fatalf("manual pending = %+v, %v", list, err)
	}
}

// TestCreateRefundGuardedSequential 顺序场景:60 通过、再 50 超退拒(60+50=110>100)、
// 再 40 通过(60+40=100 打满),验证守卫在非并发路径下的基本判定与求和口径(非 failed)。
func TestCreateRefundGuardedSequential(t *testing.T) {
	db := model.OpenTestDB(t)
	os := NewOrderStore(db)
	rs := NewRefundStore(db)
	seedPaid(t, os, "PAY-G1", 10000) // 100.00

	ok, err := rs.CreateRefundGuarded(&model.Refund{
		RefundID: "g1-a", OutTradeNo: "PAY-G1", AttemptProviderRef: "PAY-G1",
		AmountMinor: 6000, Currency: "CNY", Status: model.RefundProcessing, InitiatedBy: "business",
	}, 10000)
	if err != nil || !ok {
		t.Fatalf("g1-a: ok=%v err=%v want true,nil", ok, err)
	}

	ok, err = rs.CreateRefundGuarded(&model.Refund{
		RefundID: "g1-b", OutTradeNo: "PAY-G1", AttemptProviderRef: "PAY-G1",
		AmountMinor: 5000, Currency: "CNY", Status: model.RefundProcessing, InitiatedBy: "business",
	}, 10000)
	if err != nil || ok {
		t.Fatalf("g1-b: ok=%v err=%v want false,nil(超退应拒)", ok, err)
	}

	ok, err = rs.CreateRefundGuarded(&model.Refund{
		RefundID: "g1-c", OutTradeNo: "PAY-G1", AttemptProviderRef: "PAY-G1",
		AmountMinor: 4000, Currency: "CNY", Status: model.RefundProcessing, InitiatedBy: "business",
	}, 10000)
	if err != nil || !ok {
		t.Fatalf("g1-c: ok=%v err=%v want true,nil", ok, err)
	}

	sum, err := rs.RefundSum("PAY-G1", model.RefundRequested, model.RefundProcessing, model.RefundManualPending, model.RefundSucceeded)
	if err != nil || sum != 10000 {
		t.Fatalf("reserved sum = %d, err=%v want 10000", sum, err)
	}
	// 被拒的 g1-b 不应落库
	if _, err := rs.GetRefund("g1-b"); !errors.Is(err, ErrRefundNotFound) {
		t.Fatalf("g1-b 应未落库,GetRefund err=%v", err)
	}
}

// openFileGuardedDB 开一个 t.TempDir 下的文件型 sqlite(而非 model.OpenTestDB 的
// in-memory cache=shared),确保并发 goroutine 走真正独立的连接/文件锁路径来
// 验证 CreateRefundGuarded 的串行化 —— DSN 同样带 _txlock=immediate。
func openFileGuardedDB(t *testing.T) *gorm.DB {
	t.Helper()
	dsn := fmt.Sprintf("file:%s/guard.db?_txlock=immediate&_pragma=busy_timeout(5000)", t.TempDir())
	db, err := gorm.Open(sqlite.Open(dsn),
		&gorm.Config{Logger: logger.Default.LogMode(logger.Silent), TranslateError: true})
	if err != nil {
		t.Fatalf("open file guard db: %v", err)
	}
	if err := db.AutoMigrate(&model.OrderV2{}, &model.Attempt{}, &model.Account{}, &model.Refund{},
		&model.WebhookDelivery{}, &model.Product{}, &model.ProductPrice{}); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	sqlDB, _ := db.DB()
	t.Cleanup(func() { _ = sqlDB.Close() })
	return db
}

// TestCreateRefundGuardedConcurrentExactlyOneWins 两个 goroutine 同时对同一笔
// 100.00 已付订单各申请 60.00 退款(合计 120 > 100,必超退)。事务化守卫(锁订单行 +
// 事务内求和 + 校验 + 插入)必须让恰好一个成功、另一个被拒 —— 若把守卫换回「先
// RefundSum 再 CreateRefund」的裸读写两段式(Task 3 计划里的朴素调用法),两个
// goroutine 都可能读到 reserved=0、都通过校验、都插入成功,变成两个 true(超退)。
// 本测试即用来钉住这个回归:TDD 上手动验证过 —— 把 CreateRefundGuarded 换成裸
// RefundSum(...)+CreateRefund(...) 两步、不用事务/锁,本测试会因为「两个 true」而
// FAIL(count==2),证明测试确实在防这一类竞态,而不是摆设。
func TestCreateRefundGuardedConcurrentExactlyOneWins(t *testing.T) {
	db := openFileGuardedDB(t)
	os := NewOrderStore(db)
	rs := NewRefundStore(db)
	seedPaid(t, os, "PAY-G2", 10000) // 100.00

	var wg sync.WaitGroup
	results := make([]bool, 2)
	errs := make([]error, 2)
	ids := []string{"g2-a", "g2-b"}
	for i := 0; i < 2; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			ok, err := rs.CreateRefundGuarded(&model.Refund{
				RefundID: ids[i], OutTradeNo: "PAY-G2", AttemptProviderRef: "PAY-G2",
				AmountMinor: 6000, Currency: "CNY", Status: model.RefundProcessing, InitiatedBy: "business",
			}, 10000)
			results[i] = ok
			errs[i] = err
		}(i)
	}
	wg.Wait()

	trueCount := 0
	for i, ok := range results {
		// 允许 SQLite 忙锁重试耗尽等基础设施性错误(busy_timeout 已设为 5s 通常不会
		// 触发),但不允许"两个都成功"的超退;若出现非预期错误直接报失败方便定位。
		if errs[i] != nil {
			t.Fatalf("goroutine %d unexpected error: %v", i, errs[i])
		}
		if ok {
			trueCount++
		}
	}
	if trueCount != 1 {
		t.Fatalf("trueCount = %d, want 1 (results=%v)", trueCount, results)
	}

	sum, err := rs.RefundSum("PAY-G2", model.RefundRequested, model.RefundProcessing, model.RefundManualPending, model.RefundSucceeded)
	if err != nil || sum != 6000 {
		t.Fatalf("reserved sum = %d, err=%v want 6000(仅一笔落库)", sum, err)
	}
}