package repository

import (
	"context"
	"testing"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"

	"github.com/dhao2001/mygo/internal/model"
)

func setupUserRepo(t *testing.T) UserRepository {
	t.Helper()

	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	if err := db.AutoMigrate(&model.User{}); err != nil {
		t.Fatalf("migrate: %v", err)
	}

	return NewUserRepository(db)
}

func TestUserRepository_Create(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{
		ID:           "user-1",
		Username:     "alice",
		Email:        "alice@example.com",
		PasswordHash: "hash",
	}

	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}
}

func TestUserRepository_CreateDuplicateUsername(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	u1 := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	u2 := &model.User{ID: "user-2", Username: "alice", Email: "alice2@example.com", PasswordHash: "hash"}

	if err := repo.Create(ctx, u1); err != nil {
		t.Fatalf("Create = %v", err)
	}

	err := repo.Create(ctx, u2)
	if err != model.ErrDuplicate {
		t.Fatalf("expected ErrDuplicate, got %v", err)
	}
}

func TestUserRepository_FindByID(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	found, err := repo.FindByID(ctx, "user-1")
	if err != nil {
		t.Fatalf("FindByID = %v", err)
	}
	if found.Username != "alice" {
		t.Errorf("username = %q, want %q", found.Username, "alice")
	}
}

func TestUserRepository_FindByIDNotFound(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	_, err := repo.FindByID(ctx, "nonexistent")
	if err != model.ErrNotFound {
		t.Fatalf("expected ErrNotFound, got %v", err)
	}
}

func TestUserRepository_FindByEmail(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	found, err := repo.FindByEmail(ctx, "alice@example.com")
	if err != nil {
		t.Fatalf("FindByEmail = %v", err)
	}
	if found.ID != "user-1" {
		t.Errorf("id = %q, want %q", found.ID, "user-1")
	}
}

func TestUserRepository_FindByUsername(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	found, err := repo.FindByUsername(ctx, "alice")
	if err != nil {
		t.Fatalf("FindByUsername = %v", err)
	}
	if found.Email != "alice@example.com" {
		t.Errorf("email = %q, want %q", found.Email, "alice@example.com")
	}
}

func TestUserRepository_Update(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	user.Username = "alice2"
	if err := repo.Update(ctx, user); err != nil {
		t.Fatalf("Update = %v", err)
	}

	found, err := repo.FindByID(ctx, "user-1")
	if err != nil {
		t.Fatalf("FindByID = %v", err)
	}
	if found.Username != "alice2" {
		t.Errorf("username = %q, want %q", found.Username, "alice2")
	}
}

func TestUserRepository_Delete(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	user := &model.User{ID: "user-1", Username: "alice", Email: "alice@example.com", PasswordHash: "hash"}
	if err := repo.Create(ctx, user); err != nil {
		t.Fatalf("Create = %v", err)
	}

	if err := repo.Delete(ctx, "user-1"); err != nil {
		t.Fatalf("Delete = %v", err)
	}

	_, err := repo.FindByID(ctx, "user-1")
	if err != model.ErrNotFound {
		t.Fatalf("expected ErrNotFound after delete, got %v", err)
	}
}

func TestUserRepository_List(t *testing.T) {
	repo := setupUserRepo(t)
	ctx := context.Background()

	for i := range 5 {
		user := &model.User{
			ID:           "user-" + string(rune('0'+i)),
			Username:     "user" + string(rune('0'+i)),
			Email:        "user" + string(rune('0'+i)) + "@example.com",
			PasswordHash: "hash",
		}
		if err := repo.Create(ctx, user); err != nil {
			t.Fatalf("Create = %v", err)
		}
	}

	users, total, err := repo.List(ctx, 0, 3)
	if err != nil {
		t.Fatalf("List = %v", err)
	}
	if len(users) != 3 {
		t.Errorf("len(users) = %d, want %d", len(users), 3)
	}
	if total != 5 {
		t.Errorf("total = %d, want %d", total, 5)
	}
}