package api

import (
	"context"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/danielgtaylor/huma/v2"
	"github.com/danielgtaylor/huma/v2/adapters/humaecho"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgconn"
	"github.com/labstack/echo/v4"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"completed/internal/auth"
	"completed/internal/db"
)

// newTestAPI wires mockDB into a fresh Huma/Echo instance exactly as
// cmd/api/main.go does, so tests exercise routing and middleware, not just
// the handler bodies.
func newTestAPI(mockDB db.Querier) (*echo.Echo, huma.API) {
	e := echo.New()
	api := humaecho.New(e, huma.DefaultConfig("Test API", "1.0.0"))
	RegisterRoutes(api, mockDB)
	return e, api
}

// a fixed valid session, returned by GetSessionAndUserFunc so authed
// requests don't need a real database.
var testUserID = uuid.New()

func authedMock() *MockQuerier {
	return &MockQuerier{
		GetSessionAndUserFunc: func(ctx context.Context, tokenHash []byte) (db.GetSessionAndUserRow, error) {
			return db.GetSessionAndUserRow{ID: testUserID, Email: "a@example.com", Name: "Alice"}, nil
		},
		TouchSessionFunc: func(ctx context.Context, tokenHash []byte) error { return nil },
	}
}

// adminMock is authedMock for a session belonging to an admin, for the
// platform-mutation routes that require one.
func adminMock() *MockQuerier {
	m := authedMock()
	m.GetSessionAndUserFunc = func(ctx context.Context, tokenHash []byte) (db.GetSessionAndUserRow, error) {
		return db.GetSessionAndUserRow{ID: testUserID, Email: "a@example.com", Name: "Alice", IsAdmin: true}, nil
	}
	return m
}

func authedRequest(method, path, body string) *http.Request {
	var req *http.Request
	if body == "" {
		req = httptest.NewRequest(method, path, nil)
	} else {
		req = httptest.NewRequest(method, path, strings.NewReader(body))
		req.Header.Set("Content-Type", "application/json")
	}
	req.Header.Set("Authorization", "Bearer any-token-the-mock-accepts")
	return req
}

func TestListGamesRequiresAuth(t *testing.T) {
	e, _ := newTestAPI(&MockQuerier{})

	req := httptest.NewRequest(http.MethodGet, "/api/games", nil)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, req)

	assert.Equal(t, http.StatusUnauthorized, rec.Code)
}

func TestListGames(t *testing.T) {
	mockDB := authedMock()
	mockDB.ListGamesFunc = func(ctx context.Context, userID uuid.UUID) ([]db.ListGamesRow, error) {
		assert.Equal(t, testUserID, userID, "handler must scope the query to the authenticated user")
		return []db.ListGamesRow{
			{ID: uuid.New(), Name: "Test Game", Score: 90, PlatformName: "PC"},
		}, nil
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodGet, "/api/games", ""))

	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Body.String(), "Test Game")
	assert.Contains(t, rec.Body.String(), `"platform_name":"PC"`)
}

func TestGetGameNotFoundForOtherUsersGame(t *testing.T) {
	// A game that exists, but belongs to someone else: the query is scoped
	// by user_id, so sqlc/postgres report it as not found, same as a
	// genuinely missing id. The handler must turn that into 404, not 500.
	mockDB := authedMock()
	mockDB.GetGameFunc = func(ctx context.Context, arg db.GetGameParams) (db.GetGameRow, error) {
		assert.Equal(t, testUserID, arg.UserID, "handler must scope the lookup to the authenticated user")
		return db.GetGameRow{}, pgx.ErrNoRows
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodGet, "/api/games/"+uuid.New().String(), ""))

	assert.Equal(t, http.StatusNotFound, rec.Code)
}

func TestDeleteGameNotFoundWhenNoRowsAffected(t *testing.T) {
	mockDB := authedMock()
	mockDB.DeleteGameFunc = func(ctx context.Context, arg db.DeleteGameParams) (int64, error) {
		return 0, nil
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodDelete, "/api/games/"+uuid.New().String(), ""))

	assert.Equal(t, http.StatusNotFound, rec.Code)
}

func TestDeletePlatformConflictWhenReferencedByGames(t *testing.T) {
	// Soft delete means the FK is never actually checked by Postgres (see
	// db/query.sql's DeletePlatform comment), so the handler has to notice
	// the 0-rows result itself and turn it into 409, not just pass through
	// whatever error (if any) the query returns.
	mockDB := adminMock()
	mockDB.GetPlatformFunc = func(ctx context.Context, id uuid.UUID) (db.GetPlatformRow, error) {
		return db.GetPlatformRow{ID: id, Name: "PC"}, nil
	}
	mockDB.DeletePlatformFunc = func(ctx context.Context, id uuid.UUID) (int64, error) {
		return 0, nil
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodDelete, "/api/platforms/"+uuid.New().String(), ""))

	assert.Equal(t, http.StatusConflict, rec.Code)
}

func TestDeletePlatformNotFound(t *testing.T) {
	mockDB := adminMock()
	mockDB.GetPlatformFunc = func(ctx context.Context, id uuid.UUID) (db.GetPlatformRow, error) {
		return db.GetPlatformRow{}, pgx.ErrNoRows
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodDelete, "/api/platforms/"+uuid.New().String(), ""))

	assert.Equal(t, http.StatusNotFound, rec.Code)
}

func TestCreateGameRejectsScoreOutOfRange(t *testing.T) {
	mockDB := authedMock()
	// No CreateGameFunc set: validation must reject the request before the
	// handler ever calls the database, or this test would panic.

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	body := `{"name":"Bad","platform_id":"` + uuid.New().String() + `","score":150,"release_date":"2020-01-01"}`
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/games", body))

	assert.Equal(t, http.StatusUnprocessableEntity, rec.Code)
}

func TestCreatePlatform(t *testing.T) {
	mockDB := adminMock()
	mockDB.CreatePlatformFunc = func(ctx context.Context, name string) (db.CreatePlatformRow, error) {
		return db.CreatePlatformRow{ID: uuid.New(), Name: name}, nil
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/platforms", `{"name": "Sega Genesis"}`))

	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Body.String(), "Sega Genesis")
}

func TestCreatePlatformForbiddenForNonAdmin(t *testing.T) {
	mockDB := authedMock()
	// No CreatePlatformFunc set: the admin check must reject the request
	// before the handler ever calls the database, or this test would panic.

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/platforms", `{"name": "Sega Genesis"}`))

	assert.Equal(t, http.StatusForbidden, rec.Code)
}

func TestListPlatformsIsSharedAcrossUsers(t *testing.T) {
	// Unlike games, the platform list has no user_id to scope by: every
	// authenticated user sees the same rows. ListPlatformsFunc taking no
	// user id (beyond ctx) is itself part of what's being checked here -
	// this test would fail to compile if a user_id parameter crept back in.
	calls := 0
	mockDB := authedMock()
	mockDB.ListPlatformsFunc = func(ctx context.Context) ([]db.ListPlatformsRow, error) {
		calls++
		return []db.ListPlatformsRow{{ID: uuid.New(), Name: "PC"}}, nil
	}

	e, _ := newTestAPI(mockDB)

	rec := httptest.NewRecorder()
	e.ServeHTTP(rec, authedRequest(http.MethodGet, "/api/platforms", ""))
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Body.String(), "PC")
	assert.Equal(t, 1, calls)
}

func TestRegisterDuplicateEmailConflicts(t *testing.T) {
	mockDB := &MockQuerier{
		CreateUserFunc: func(ctx context.Context, arg db.CreateUserParams) (db.CreateUserRow, error) {
			return db.CreateUserRow{}, &pgconn.PgError{Code: pgCodeUniqueViolation}
		},
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	body := `{"email":"a@example.com","password":"password123","name":"Alice"}`
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/auth/register", body))

	assert.Equal(t, http.StatusConflict, rec.Code)
}

func TestLoginWrongPasswordUnauthorized(t *testing.T) {
	hash, err := auth.HashPassword("correct-password")
	require.NoError(t, err)

	mockDB := &MockQuerier{
		GetUserByEmailFunc: func(ctx context.Context, email string) (db.GetUserByEmailRow, error) {
			return db.GetUserByEmailRow{ID: testUserID, Email: email, PasswordHash: hash}, nil
		},
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	body := `{"email":"a@example.com","password":"wrong-password"}`
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/auth/login", body))

	assert.Equal(t, http.StatusUnauthorized, rec.Code)
}

func TestLoginSuccessSetsSessionCookie(t *testing.T) {
	hash, err := auth.HashPassword("correct-password")
	require.NoError(t, err)

	mockDB := &MockQuerier{
		GetUserByEmailFunc: func(ctx context.Context, email string) (db.GetUserByEmailRow, error) {
			return db.GetUserByEmailRow{ID: testUserID, Email: email, Name: "Alice", PasswordHash: hash}, nil
		},
		CreateSessionFunc: func(ctx context.Context, arg db.CreateSessionParams) error {
			assert.Equal(t, testUserID, arg.UserID)
			return nil
		},
	}

	e, _ := newTestAPI(mockDB)
	rec := httptest.NewRecorder()
	body := `{"email":"a@example.com","password":"correct-password"}`
	e.ServeHTTP(rec, authedRequest(http.MethodPost, "/api/auth/login", body))

	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Contains(t, rec.Header().Get("Set-Cookie"), "session=")
}