package drivers

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
)

type memoryStore struct {
	drivers map[string]Driver
}

func newMemoryStore() *memoryStore {
	return &memoryStore{drivers: make(map[string]Driver)}
}

func (m *memoryStore) Exec(ctx context.Context, sql string) (int64, error) {
	return 0, nil
}

func (m *memoryStore) Create(ctx context.Context, d Driver) error {
	for _, existing := range m.drivers {
		if existing.Nickname == d.Nickname {
			return &pgconn.PgError{Code: "23505", Message: "duplicate key value violates unique constraint"}
		}
	}
	m.drivers[d.ID] = d
	return nil
}

func (m *memoryStore) Get(ctx context.Context, id string) (Driver, error) {
	d, ok := m.drivers[id]
	if !ok {
		return Driver{}, ErrNotFound
	}
	return d, nil
}

func (m *memoryStore) GetByNickname(ctx context.Context, nick string) (Driver, error) {
	for _, d := range m.drivers {
		if d.Nickname == nick {
			return d, nil
		}
	}
	return Driver{}, ErrNotFound
}

func (m *memoryStore) List(ctx context.Context, limit, offset int, clanID string) ([]Driver, error) {
	out := make([]Driver, 0)
	for _, d := range m.drivers {
		if clanID == "" || d.ClanID == clanID {
			out = append(out, d)
		}
	}
	return out, nil
}

func (m *memoryStore) Delete(ctx context.Context, id string) error {
	if _, ok := m.drivers[id]; !ok {
		return ErrNotFound
	}
	delete(m.drivers, id)
	return nil
}

func (m *memoryStore) Update(ctx context.Context, d Driver) error {
	if _, ok := m.drivers[d.ID]; !ok {
		return ErrNotFound
	}
	for id, existing := range m.drivers {
		if id != d.ID && existing.Nickname == d.Nickname {
			return &pgconn.PgError{Code: "23505", Message: "duplicate key value violates unique constraint"}
		}
	}
	m.drivers[d.ID] = d
	return nil
}

func (m *memoryStore) Count(ctx context.Context) (int, error) {
	return len(m.drivers), nil
}

func TestDriversService(t *testing.T) {
	store := newMemoryStore()
	svc := NewService(store)
	svc.now = func() time.Time {
		return time.Unix(1700000000, 0)
	}
	ctx := context.Background()

	// 1. Create a driver
	d1, err := svc.Create(ctx, CreateInput{
		ID:        "driver-1",
		Nickname:  "HAM",
		Name:      "Lewis Hamilton",
		AvatarURL: "https://example.com/ham.png",
		ClanID:    "clan-1",
	})
	if err != nil {
		t.Fatalf("Create failed: %v", err)
	}
	if d1.ID != "driver-1" || d1.Nickname != "HAM" || d1.Name != "Lewis Hamilton" || d1.ClanID != "clan-1" {
		t.Errorf("Unexpected created driver: %+v", d1)
	}

	// 2. Validate Nickname must be 3 uppercase ASCII letters
	_, err = svc.Create(ctx, CreateInput{Nickname: "HAMILTON", Name: "toolong"})
	if !errors.Is(err, ErrInvalidInput) {
		t.Errorf("Expected ErrInvalidInput for tag 'HAMILTON', got: %v", err)
	}

	// 3. Validate empty Name is rejected
	_, err = svc.Create(ctx, CreateInput{Nickname: "BOT", Name: ""})
	if !errors.Is(err, ErrInvalidInput) {
		t.Errorf("Expected ErrInvalidInput for empty name, got: %v", err)
	}

	// 4. Duplicate nickname check
	_, err = svc.Create(ctx, CreateInput{
		ID:       "driver-2",
		Nickname: "HAM",
		Name:     "Another Lewis",
	})
	if !errors.Is(err, ErrAlreadyExists) {
		t.Errorf("Expected ErrAlreadyExists for duplicate nickname, got: %v", err)
	}

	// 5. Get driver
	got, err := svc.Get(ctx, "driver-1")
	if err != nil {
		t.Fatalf("Get failed: %v", err)
	}
	if got.Nickname != "HAM" {
		t.Errorf("Expected HAM, got %s", got.Nickname)
	}

	// 6. Get by nickname
	gotByNick, err := svc.GetByNickname(ctx, "ham") // should normalize to HAM
	if err != nil {
		t.Fatalf("GetByNickname failed: %v", err)
	}
	if gotByNick.ID != "driver-1" {
		t.Errorf("Expected driver-1, got %s", gotByNick.ID)
	}

	// 7. Update driver (including nickname)
	clanID := "clan-2"
	updated, err := svc.Update(ctx, "driver-1", UpdateInput{
		Nickname:  "VET",
		Name:      "Lewis Hamilton MBE",
		AvatarURL: "https://example.com/ham-mbe.png",
		ClanID:    &clanID,
	})
	if err != nil {
		t.Fatalf("Update failed: %v", err)
	}
	if updated.Nickname != "VET" || updated.Name != "Lewis Hamilton MBE" || updated.AvatarURL != "https://example.com/ham-mbe.png" || updated.ClanID != "clan-2" {
		t.Errorf("Unexpected updated driver fields: %+v", updated)
	}

	// 7a. Update with invalid nickname
	_, err = svc.Update(ctx, "driver-1", UpdateInput{Nickname: "TOOLONG"})
	if !errors.Is(err, ErrInvalidInput) {
		t.Errorf("Expected ErrInvalidInput for invalid nickname update, got: %v", err)
	}

	// 7b. Create driver-2 to test duplicate nickname conflict
	_, err = svc.Create(ctx, CreateInput{
		ID:        "driver-2",
		Nickname:  "HAM",
		Name:      "Lewis",
	})
	if err != nil {
		t.Fatalf("Create driver-2 failed: %v", err)
	}

	// 7c. Update driver-2 to nickname "VET" (should fail, already taken by driver-1)
	_, err = svc.Update(ctx, "driver-2", UpdateInput{Nickname: "VET"})
	if !errors.Is(err, ErrAlreadyExists) {
		t.Errorf("Expected ErrAlreadyExists for duplicate nickname update, got: %v", err)
	}

	// 8. Delete driver
	err = svc.Delete(ctx, "driver-1")
	if err != nil {
		t.Fatalf("Delete failed: %v", err)
	}
	_, err = svc.Get(ctx, "driver-1")
	if !errors.Is(err, ErrNotFound) {
		t.Errorf("Expected ErrNotFound after deletion, got: %v", err)
	}
}