package draw

import (
	"context"
	"database/sql"
	"database/sql/driver"
	"encoding/json"
	"errors"
	"fmt"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/perfect-panel/server/internal/model/lottery"
	"github.com/perfect-panel/server/pkg/xerr"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

// ---- test fakes ------------------------------------------------------------

type fakeRateLimiter struct {
	mu    sync.Mutex
	err   error
	calls int
}

func (f *fakeRateLimiter) Allow(_ context.Context, _ int64) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.calls++
	return f.err
}

type fakeChance struct {
	mu               sync.Mutex
	consumeRemaining int64
	consumeErr       error
	consumeCalls     int
	queryRemaining   int64
}

func (f *fakeChance) Grant(context.Context, int64, int64, string, string, int) error {
	return nil
}
func (f *fakeChance) Consume(_ context.Context, _ *gorm.DB, _, _ int64) (int64, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.consumeCalls++
	if f.consumeErr != nil {
		return 0, f.consumeErr
	}
	return f.consumeRemaining, nil
}
func (f *fakeChance) Query(_ context.Context, _, _ int64) (int64, error) {
	return f.queryRemaining, nil
}

type fakeEvaluator struct {
	passed bool
	unmet  []lottery.UnmetReason
	err    error
}

func (f *fakeEvaluator) Evaluate(context.Context, *lottery.EligibilityRule, lottery.RuleContext) (bool, []lottery.UnmetReason, error) {
	return f.passed, f.unmet, f.err
}

type fakePicker struct {
	idx int
	err error
}

func (f *fakePicker) Pick([]lottery.Prize) (int, error) { return f.idx, f.err }

type fakeContextBuilder struct{}

func (fakeContextBuilder) Build(_ context.Context, uid int64) (lottery.RuleContext, error) {
	return lottery.RuleContext{UserId: uid}, nil
}

type recordingHandler struct {
	handlerType string
	auto        bool
	result      lottery.DispatchResult
	err         error
	calls       int
}

func (h *recordingHandler) Type() string { return h.handlerType }
func (h *recordingHandler) IsAuto() bool { return h.auto }
func (h *recordingHandler) Dispatch(_ context.Context, _ *gorm.DB, _ lottery.DispatchRequest) (lottery.DispatchResult, error) {
	h.calls++
	return h.result, h.err
}
func (h *recordingHandler) ValidateClaim([]byte) error   { return nil }
func (h *recordingHandler) ClaimSchema() json.RawMessage { return nil }

// stubRegistry only knows what we register.
type stubRegistry struct {
	handlers map[string]lottery.PrizeHandler
}

func (r *stubRegistry) Get(t string) (lottery.PrizeHandler, bool) {
	h, ok := r.handlers[t]
	return h, ok
}
func (r *stubRegistry) MustGet(t string) (lottery.PrizeHandler, error) {
	if h, ok := r.handlers[t]; ok {
		return h, nil
	}
	return nil, lottery.ErrHandlerNotRegistered
}

// ---- shared harness --------------------------------------------------------

func newTestDB(t *testing.T) (*gorm.DB, sqlmock.Sqlmock, func()) {
	t.Helper()
	sqlDB, mock, err := sqlmock.New(sqlmock.QueryMatcherOption(sqlmock.QueryMatcherFunc(func(expected, actual string) error {
		if strings.Contains(actual, expected) {
			return nil
		}
		return fmt.Errorf("actual sql %q does not contain %q", actual, expected)
	})))
	if err != nil {
		t.Fatalf("sqlmock: %v", err)
	}
	db, err := gorm.Open(mysql.New(mysql.Config{Conn: sqlDB, SkipInitializeWithVersion: true}), &gorm.Config{})
	if err != nil {
		_ = sqlDB.Close()
		t.Fatalf("gorm: %v", err)
	}
	return db, mock, func() { _ = sqlDB.Close() }
}

// expectRunningActivity sets up the pre-tx activity load.
func expectRunningActivity(mock sqlmock.Sqlmock, activityId int64) {
	now := time.Now()
	mock.ExpectQuery("FROM `lottery_activity`").
		WillReturnRows(sqlmock.NewRows([]string{
			"id", "title", "start_at", "end_at", "status", "grid_size", "eligibility", "chance_sources", "unmet_action",
		}).AddRow(activityId, "test", now.Add(-1*time.Hour), now.Add(24*time.Hour), lottery.ActivityStatusRunning, 9, "{}", "[]", "block"))
}

// expectPrizePool sets up the pre-tx prize load.
func expectPrizePool(mock sqlmock.Sqlmock, activityId int64, prizes ...lottery.Prize) {
	rows := sqlmock.NewRows([]string{"id", "activity_id", "slot", "type", "name", "icon_url", "config", "weight", "total_stock", "remaining_stock", "is_fallback", "version"})
	for _, p := range prizes {
		rows.AddRow(p.Id, p.ActivityId, p.Slot, p.Type, p.Name, p.IconURL, p.Config, p.Weight, p.TotalStock, p.RemainingStock, p.IsFallback, p.Version)
	}
	mock.ExpectQuery("FROM `lottery_prize`").WillReturnRows(rows)
}

// expectExistingDrawEmpty sets up the tx-inner nonce lookup returning no rows.
func expectExistingDrawEmpty(mock sqlmock.Sqlmock) {
	mock.ExpectQuery("FROM `lottery_draw`").WillReturnError(gorm.ErrRecordNotFound)
}

// ---- Test cases ------------------------------------------------------------

func TestDraw_RejectsWhenFeatureFlagDisabled(t *testing.T) {
	db, _, cleanup := newTestDB(t)
	defer cleanup()

	svc := NewService(Deps{
		DB:      db,
		Enabled: false,
	})
	_, err := svc.Draw(context.Background(), Request{UserId: 42, ActivityId: 100, ClientNonce: "n1"})
	code, ok := errAsCode(err)
	if !ok || code != xerr.LotteryActivityEnded {
		t.Fatalf("expected LotteryActivityEnded when disabled, got %v", err)
	}
}

func TestDraw_ValidatesRequest(t *testing.T) {
	db, _, cleanup := newTestDB(t)
	defer cleanup()

	svc := NewService(Deps{DB: db, Enabled: true})
	cases := []Request{
		{UserId: 0, ActivityId: 1, ClientNonce: "n"},
		{UserId: 1, ActivityId: 0, ClientNonce: "n"},
		{UserId: 1, ActivityId: 1, ClientNonce: ""},
		{UserId: 1, ActivityId: 1, ClientNonce: strings.Repeat("x", 65)},
	}
	for i, c := range cases {
		if _, err := svc.Draw(context.Background(), c); err == nil {
			t.Fatalf("case %d expected error, got nil", i)
		}
	}
}

func TestDraw_RateLimited(t *testing.T) {
	db, _, cleanup := newTestDB(t)
	defer cleanup()

	limiter := &fakeRateLimiter{err: ErrRateLimited}
	svc := NewService(Deps{DB: db, Enabled: true, RateLimiter: limiter})
	_, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 1, ClientNonce: "n"})
	code, ok := errAsCode(err)
	if !ok || code != xerr.LotteryRateLimited {
		t.Fatalf("expected LotteryRateLimited, got %v", err)
	}
}

func TestDraw_NonceIdempotency_ReturnsExisting(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100, lottery.Prize{Id: 1, ActivityId: 100, Slot: 0, Type: lottery.PrizeTypeNone, Name: "谢谢参与", Config: "{}", Weight: 1})

	mock.ExpectBegin()
	// nonce hit — the flow short-circuits
	mock.ExpectQuery("FROM `lottery_draw`").
		WillReturnRows(sqlmock.NewRows([]string{"id", "user_id", "activity_id", "client_nonce", "prize_id", "is_win", "dispatch_state", "drawn_at"}).
			AddRow(int64(999), int64(42), int64(100), "same-nonce", nil, false, lottery.DispatchStateAutoClaimed, time.Now()))
	// snapshot lookup
	mock.ExpectQuery("FROM `lottery_prize_snapshot`").
		WillReturnRows(sqlmock.NewRows([]string{"id", "draw_id", "prize_id", "slot", "type", "name", "config"}).
			AddRow(int64(1), int64(999), int64(0), 0, lottery.PrizeTypeNone, "谢谢参与", "{}"))
	mock.ExpectCommit()

	chance := &fakeChance{queryRemaining: 3}
	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         chance,
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 42, ActivityId: 100, ClientNonce: "same-nonce"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if res.DrawId != 999 {
		t.Fatalf("expected reuse existing draw id=999, got %d", res.DrawId)
	}
	if chance.consumeCalls != 0 {
		t.Fatalf("must NOT Consume a chance on nonce replay")
	}
}

func TestDraw_NoChancesReturnsCode(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100, lottery.Prize{Id: 1, ActivityId: 100, Slot: 0, Type: lottery.PrizeTypeNone, Name: "谢谢参与", Config: "{}", Weight: 1})

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectRollback()

	chance := &fakeChance{consumeErr: lottery.ErrNoChances}
	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         chance,
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	_, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "n"})
	code, ok := errAsCode(err)
	if !ok || code != xerr.LotteryNoChances {
		t.Fatalf("expected LotteryNoChances, got %v", err)
	}
}

func TestDraw_NotEligibleRejectsBeforeConsume(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{},
		Evaluator:      &fakeEvaluator{passed: false, unmet: []lottery.UnmetReason{{Rule: "invite_count", Hint: "need 3"}}},
		Picker:         &fakePicker{},
		Registry:       &stubRegistry{},
		ContextBuilder: fakeContextBuilder{},
	})
	_, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "n"})
	code, ok := errAsCode(err)
	if !ok || code != xerr.LotteryNotEligible {
		t.Fatalf("expected LotteryNotEligible, got %v", err)
	}
	// Ensure no mock expectations remain (we didn't set up prize load).
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("expectations: %v", err)
	}
}

func TestDraw_SuccessAutoClaimedNoneReturnsDrawWithoutDispatch(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	// Two prizes: one none (weight 100) — picker returns idx 0 always
	expectPrizePool(mock, 100,
		lottery.Prize{Id: 1, ActivityId: 100, Slot: 0, Type: lottery.PrizeTypeNone, Name: "谢谢参与", Config: "{}", Weight: 100},
	)

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	// insert draw
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(555, 1))
	// insert prize_snapshot
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	// insert eligibility_snapshot
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	// finalize draw state
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	chance := &fakeChance{consumeRemaining: 2}
	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         chance,
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "unique-1"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if res.IsWin {
		t.Fatalf("none prize should not count as win")
	}
	if res.DrawId == 0 {
		t.Fatalf("expected draw id from LastInsertId")
	}
	if res.ChancesRemaining != 2 {
		t.Fatalf("expected remaining=2 from Consume, got %d", res.ChancesRemaining)
	}
}

func TestDraw_LimitedStockFallback(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	// prize 0 = limited (remaining=0 → sold out); prize 1 = fallback
	expectPrizePool(mock, 100,
		lottery.Prize{Id: 10, ActivityId: 100, Slot: 0, Type: "vpn_duration", Name: "3天", Config: `{"duration_days":3}`, Weight: 100, TotalStock: sql.NullInt64{Int64: 1, Valid: true}, RemainingStock: sql.NullInt64{Int64: 1, Valid: true}},
		lottery.Prize{Id: 20, ActivityId: 100, Slot: 1, Type: lottery.PrizeTypeNone, Name: "谢谢参与", Config: "{}", Weight: 0, IsFallback: true},
	)

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	// stock decrement returns 0 rows affected → sold out
	mock.ExpectExec("UPDATE `lottery_prize`").
		WillReturnResult(sqlmock.NewResult(0, 0))
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(778, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{consumeRemaining: 1},
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "n"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if res.IsWin {
		t.Fatalf("fallback none should not win")
	}
	if res.DrawId != 778 {
		t.Fatalf("expected draw id 778, got %d", res.DrawId)
	}
}

func TestDraw_WinCallsAutoHandlerDispatch(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100,
		lottery.Prize{Id: 30, ActivityId: 100, Slot: 5, Type: lottery.PrizeTypeVPNDuration, Name: "3 天", Config: `{"duration_days":3}`, Weight: 100},
	)

	handler := &recordingHandler{
		handlerType: lottery.PrizeTypeVPNDuration,
		auto:        true,
		result:      lottery.DispatchResult{State: lottery.DispatchStateAutoClaimed, Message: "已加 3 天"},
	}

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(1234, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{consumeRemaining: 0},
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{lottery.PrizeTypeVPNDuration: handler}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "w"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if !res.IsWin {
		t.Fatalf("expected IsWin=true for vpn_duration")
	}
	if handler.calls != 1 {
		t.Fatalf("expected handler.Dispatch called once, got %d", handler.calls)
	}
	if res.Claim.AutoClaimed != true {
		t.Fatalf("expected AutoClaimed=true, got %+v", res.Claim)
	}
	if res.Message != "已加 3 天" {
		t.Fatalf("expected message from Dispatch, got %q", res.Message)
	}
	if res.Prize == nil || res.Prize.Type != lottery.PrizeTypeVPNDuration {
		t.Fatalf("expected prize summary, got %+v", res.Prize)
	}
	// Prize.Config should be embedded json.RawMessage — verify decodes
	var cfg map[string]any
	if err := json.Unmarshal(res.Prize.Config, &cfg); err != nil {
		t.Fatalf("Prize.Config invalid: %v", err)
	}
	if cfg["duration_days"].(float64) != 3 {
		t.Fatalf("expected duration_days=3, got %v", cfg["duration_days"])
	}
}

func TestDraw_UnregisteredAutoHandlerFallsBackToPendingClaim(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100,
		lottery.Prize{Id: 40, ActivityId: 100, Slot: 0, Type: "encrypted", Name: "Encrypted", Config: "{}", Weight: 100},
	)

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{consumeRemaining: 0},
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "w2"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if res.Claim.Required != true {
		t.Fatalf("expected Claim.Required=true when handler unregistered, got %+v", res.Claim)
	}
}

// errAsCode helps assert xerr.CodeError codes.
func errAsCode(err error) (uint32, bool) {
	if err == nil {
		return 0, false
	}
	var ce *xerr.CodeError
	if errors.As(err, &ce) {
		return ce.GetErrCode(), true
	}
	return 0, false
}

// TestInsertSnapshots_UnmetReasonsIsValidJSON is the F4 regression guard
// (kept from PR E — must survive Stage 2 rebase).
//
// Before PR E, insertSnapshots created lottery_eligibility_snapshot rows with
// UnmetReasons="" — MySQL error 3140 rejects empty strings on JSON columns,
// so every real /draw request 100% failed the tx commit even though sqlmock
// (which does no JSON validation) was happy. This test snapshots the exact
// INSERT arg values and asserts:
//  1. UnmetReasons must never be "" (it should be "[]")
//  2. EvaluatedAt must not be the zero time.Time (STRICT sql_mode rejects
//     '0000-00-00 00:00:00' on DATETIME NOT NULL)
//
// sqlmock cannot catch the JSON validity itself — only real MySQL can — but
// it can catch the two upstream bugs that let bad values through the Go
// layer. This is a defense-in-depth check.
func TestInsertSnapshots_UnmetReasonsIsValidJSON(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100, lottery.Prize{
		Id: 1, ActivityId: 100, Slot: 0, Type: lottery.PrizeTypeNone, Name: "谢谢参与", Config: "{}", Weight: 100,
	})

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(555, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))

	// Field order matches EligibilitySnapshot struct-tag order under GORM:
	//   draw_id, user_id, activity_id, passed, unmet_reasons, evaluated_at.
	// We assert UnmetReasons=="[]" (never "") and EvaluatedAt is non-zero.
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WithArgs(
			sqlmock.AnyArg(),        // draw_id
			sqlmock.AnyArg(),        // user_id
			sqlmock.AnyArg(),        // activity_id
			sqlmock.AnyArg(),        // passed
			unmetReasonsNotEmpty{t}, // MUST be "[]"
			evaluatedAtNotZero{t},   // MUST be non-zero time
		).
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{consumeRemaining: 2},
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{}},
		ContextBuilder: fakeContextBuilder{},
	})
	_, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "f4-regression"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("expectations: %v", err)
	}
}

// unmetReasonsNotEmpty is a per-arg matcher: the value MUST be the string
// "[]"; the empty string is the exact F4 regression we are guarding against.
type unmetReasonsNotEmpty struct{ t *testing.T }

func (m unmetReasonsNotEmpty) Match(v driver.Value) bool {
	s, ok := v.(string)
	if !ok {
		m.t.Fatalf("F4 guard: expected string for UnmetReasons, got %T (%v)", v, v)
	}
	if s == "" {
		m.t.Fatalf("F4 regression: UnmetReasons must not be empty string (MySQL error 3140)")
	}
	if s != "[]" {
		m.t.Fatalf("F4 guard: expected UnmetReasons==%q, got %q", "[]", s)
	}
	return true
}

// evaluatedAtNotZero is a per-arg matcher: the value MUST be a non-zero
// time.Time; the zero time is the F5 regression that STRICT sql_mode rejects
// as '0000-00-00 00:00:00'.
type evaluatedAtNotZero struct{ t *testing.T }

func (m evaluatedAtNotZero) Match(v driver.Value) bool {
	tv, ok := v.(time.Time)
	if !ok {
		m.t.Fatalf("F5 guard: expected time.Time for EvaluatedAt, got %T (%v)", v, v)
	}
	if tv.IsZero() {
		m.t.Fatalf("F5 regression: EvaluatedAt must not be zero time")
	}
	return true
}

// ---- Stage 2 (manual claim) tests ----------------------------------------

// TestDraw_ManualClaimHandlerInsertsPendingClaim 验证：命中 IsAuto()==false
// 的 handler 时，draw 事务里会 INSERT lottery_claim 并返回 ExpiresAt + Schema。
// 复用 PR E 的 F4/F5 matcher 断言 EligibilitySnapshot 守卫在人工奖分支同样生效。
func TestDraw_ManualClaimHandlerInsertsPendingClaim(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100,
		lottery.Prize{
			Id: 50, ActivityId: 100, Slot: 3, Type: lottery.PrizeTypeCrypto,
			Name:   "1 BTC",
			Config: `{"amount":"1","currency":"BTC","networks":["BTC","TRX"],"claim_ttl_hours":48}`,
			Weight: 100,
		},
	)

	manualHandler := &recordingHandler{
		handlerType: lottery.PrizeTypeCrypto,
		auto:        false,
	}

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(5678, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	// F4/F5 regression guards MUST hold on manual-claim path too.
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WithArgs(
			sqlmock.AnyArg(),        // draw_id
			sqlmock.AnyArg(),        // user_id
			sqlmock.AnyArg(),        // activity_id
			sqlmock.AnyArg(),        // passed
			unmetReasonsNotEmpty{t}, // MUST be "[]"
			evaluatedAtNotZero{t},   // MUST be non-zero time
		).
		WillReturnResult(sqlmock.NewResult(1, 1))
	// pending_claim row insert
	mock.ExpectExec("INSERT INTO `lottery_claim`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	// finalize draw.dispatch_state = pending_claim
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:             db,
		Enabled:        true,
		Chance:         &fakeChance{consumeRemaining: 0},
		Evaluator:      &fakeEvaluator{passed: true},
		Picker:         &fakePicker{idx: 0},
		Registry:       &stubRegistry{handlers: map[string]lottery.PrizeHandler{lottery.PrizeTypeCrypto: manualHandler}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 1, ActivityId: 100, ClientNonce: "manual1"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if manualHandler.calls != 0 {
		t.Fatalf("manual handler.Dispatch must NOT be called, got %d calls", manualHandler.calls)
	}
	if !res.Claim.Required {
		t.Fatalf("expected Claim.Required=true, got %+v", res.Claim)
	}
	if res.Claim.AutoClaimed {
		t.Fatalf("expected AutoClaimed=false for manual, got %+v", res.Claim)
	}
	if res.Claim.ExpiresAt == 0 {
		t.Fatal("expected non-zero ExpiresAt")
	}
	// 48h TTL from prize config
	expected := time.Now().Add(48 * time.Hour).Unix()
	if diff := res.Claim.ExpiresAt - expected; diff > 5 || diff < -5 {
		t.Fatalf("ExpiresAt off by %ds; got %d expected ~%d", diff, res.Claim.ExpiresAt, expected)
	}
	// crypto handler builds schema with enum injected from prize config
	if len(res.Claim.ClaimFormSchema) == 0 {
		t.Fatal("expected ClaimFormSchema for crypto")
	}
	if !strings.Contains(string(res.Claim.ClaimFormSchema), `"enum":["BTC","TRX"]`) {
		t.Fatalf("expected enum with BTC/TRX in schema, got %s", res.Claim.ClaimFormSchema)
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("expectations: %v", err)
	}
}

// TestDraw_ManualClaimDefaultsTo7DayTTL 验证：奖品 config 没写 claim_ttl_hours
// 时，落在默认 168h（7 天）窗口。
func TestDraw_ManualClaimDefaultsTo7DayTTL(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100,
		lottery.Prize{
			Id: 60, ActivityId: 100, Slot: 4, Type: lottery.PrizeTypePhysical,
			Name:   "T-shirt",
			Config: `{"sku_id":"tee-01","sku_name":"限量 T 恤"}`,
			Weight: 100,
		},
	)

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(9001, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WithArgs(
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			unmetReasonsNotEmpty{t}, // F4 guard also applies here
			evaluatedAtNotZero{t},   // F5 guard also applies here
		).
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_claim`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:        db,
		Enabled:   true,
		Chance:    &fakeChance{consumeRemaining: 0},
		Evaluator: &fakeEvaluator{passed: true},
		Picker:    &fakePicker{idx: 0},
		Registry: &stubRegistry{handlers: map[string]lottery.PrizeHandler{
			lottery.PrizeTypePhysical: &recordingHandler{handlerType: lottery.PrizeTypePhysical, auto: false},
		}},
		ContextBuilder: fakeContextBuilder{},
	})
	res, err := svc.Draw(context.Background(), Request{UserId: 2, ActivityId: 100, ClientNonce: "manual2"})
	if err != nil {
		t.Fatalf("Draw: %v", err)
	}
	expected := time.Now().Add(time.Duration(lottery.DefaultClaimTTLHours) * time.Hour).Unix()
	if diff := res.Claim.ExpiresAt - expected; diff > 5 || diff < -5 {
		t.Fatalf("expected default 7-day TTL, got diff=%ds", diff)
	}
}

// TestDraw_ManualClaimClaimDataIsValidJSON is the F7 regression guard
// (HIF-11): the Stage 2 manual-claim path inserts a lottery_claim row inside
// the draw tx; Claim.ClaimData is declared `gorm:"type:json"` and MySQL error
// 3140 rejects the Go zero value "" on JSON columns. Same class of bug as
// PR E (UnmetReasons="[]") and PR F (GrantLedger.Payload="{}").
//
// The regression before the fix: 100% of manual-prize draws (crypto /
// physical / manual_other) hit `100500 insert lottery_claim for draw N:
// Error 3140 (22032): Invalid JSON text: "The document is empty."`.
//
// sqlmock does no JSON validation, but this per-arg matcher snapshots the
// exact ClaimData bind value and fails if it's the empty string — the exact
// Go-layer bug real MySQL would reject downstream.
func TestDraw_ManualClaimClaimDataIsValidJSON(t *testing.T) {
	db, mock, cleanup := newTestDB(t)
	defer cleanup()

	expectRunningActivity(mock, 100)
	expectPrizePool(mock, 100, lottery.Prize{
		Id: 70, ActivityId: 100, Slot: 5, Type: lottery.PrizeTypeManualOther,
		Name:   "定制手办",
		Config: `{"sku_name":"定制"}`,
		Weight: 100,
	})

	mock.ExpectBegin()
	expectExistingDrawEmpty(mock)
	mock.ExpectExec("INSERT INTO `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(7777, 1))
	mock.ExpectExec("INSERT INTO `lottery_prize_snapshot`").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("INSERT INTO `lottery_eligibility_snapshot`").
		WithArgs(
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			sqlmock.AnyArg(),
			unmetReasonsNotEmpty{t}, // F4 guard survives
			evaluatedAtNotZero{t},   // F5 guard survives
		).
		WillReturnResult(sqlmock.NewResult(1, 1))
	// Actual GORM bind order (nullable *time.Time fields — SubmittedAt,
	// ReviewedAt, PaidAt — are elided when nil):
	//   draw_id, user_id, activity_id, prize_type, claim_data, status,
	//   expires_at, reviewed_by, reject_reason, tx_hash, delivery_ref,
	//   created_at, updated_at.
	// Assert ClaimData (position 5) is valid JSON — never "".
	mock.ExpectExec("INSERT INTO `lottery_claim`").
		WithArgs(
			sqlmock.AnyArg(),        // draw_id
			sqlmock.AnyArg(),        // user_id
			sqlmock.AnyArg(),        // activity_id
			sqlmock.AnyArg(),        // prize_type
			claimDataIsValidJSON{t}, // MUST be valid JSON, not ""
			sqlmock.AnyArg(),        // status
			sqlmock.AnyArg(),        // expires_at
			sqlmock.AnyArg(),        // reviewed_by
			sqlmock.AnyArg(),        // reject_reason
			sqlmock.AnyArg(),        // tx_hash
			sqlmock.AnyArg(),        // delivery_ref
			sqlmock.AnyArg(),        // created_at
			sqlmock.AnyArg(),        // updated_at
		).
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectExec("UPDATE `lottery_draw`").
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectCommit()

	svc := NewService(Deps{
		DB:        db,
		Enabled:   true,
		Chance:    &fakeChance{consumeRemaining: 0},
		Evaluator: &fakeEvaluator{passed: true},
		Picker:    &fakePicker{idx: 0},
		Registry: &stubRegistry{handlers: map[string]lottery.PrizeHandler{
			lottery.PrizeTypeManualOther: &recordingHandler{handlerType: lottery.PrizeTypeManualOther, auto: false},
		}},
		ContextBuilder: fakeContextBuilder{},
	})
	if _, err := svc.Draw(context.Background(), Request{UserId: 87437, ActivityId: 100, ClientNonce: "hif-11-regression"}); err != nil {
		t.Fatalf("Draw: %v", err)
	}
	if err := mock.ExpectationsWereMet(); err != nil {
		t.Fatalf("expectations: %v", err)
	}
}

// claimDataIsValidJSON is a per-arg matcher: the value MUST be a non-empty
// string that parses as valid JSON. The exact regression (HIF-11) is
// ClaimData=="" — MySQL error 3140 rejects it on JSON columns.
type claimDataIsValidJSON struct{ t *testing.T }

func (m claimDataIsValidJSON) Match(v driver.Value) bool {
	s, ok := v.(string)
	if !ok {
		m.t.Fatalf("F7 guard: expected string for ClaimData, got %T (%v)", v, v)
	}
	if s == "" {
		m.t.Fatalf("F7 regression (HIF-11): ClaimData must not be empty string (MySQL error 3140)")
	}
	if !json.Valid([]byte(s)) {
		m.t.Fatalf("F7 guard: ClaimData must be valid JSON, got %q", s)
	}
	return true
}