package cache

import (
	"context"
	"encoding/json"
	"errors"
	"sync"
	"testing"
	"time"

	"tercul/internal/domain"

	"gorm.io/gorm"

	"github.com/stretchr/testify/require"
)

// memCacheT - small in-memory cache for translation tests
type memCacheT struct {
	m  map[string][]byte
	mu sync.RWMutex
}

func newMemCacheT() *memCacheT { return &memCacheT{m: map[string][]byte{}} }
func (c *memCacheT) Get(_ context.Context, key string, value interface{}) error {
	c.mu.RLock()
	defer c.mu.RUnlock()
	b, ok := c.m[key]
	if !ok {
		return errors.New("cache miss")
	}
	return json.Unmarshal(b, value)
}
func (c *memCacheT) Set(_ context.Context, key string, value interface{}, expiration time.Duration) error {
	b, err := json.Marshal(value)
	if err != nil {
		return err
	}
	c.mu.Lock()
	defer c.mu.Unlock()
	c.m[key] = b
	return nil
}
func (c *memCacheT) Delete(_ context.Context, key string) error {
	c.mu.Lock()
	delete(c.m, key)
	c.mu.Unlock()
	return nil
}
func (c *memCacheT) Clear(_ context.Context) error {
	c.mu.Lock()
	c.m = map[string][]byte{}
	c.mu.Unlock()
	return nil
}
func (c *memCacheT) GetMulti(_ context.Context, keys []string) (map[string][]byte, error) {
	res := map[string][]byte{}
	c.mu.RLock()
	defer c.mu.RUnlock()
	for _, k := range keys {
		if v, ok := c.m[k]; ok {
			res[k] = v
		}
	}
	return res, nil
}
func (c *memCacheT) SetMulti(_ context.Context, items map[string]interface{}, expiration time.Duration) error {
	for k, v := range items {
		b, _ := json.Marshal(v)
		c.m[k] = b
	}
	return nil
}

// dummyTranslationRepo implements domain.TranslationRepository minimal functionality for tests
type dummyTranslationRepo struct {
	store map[uint]*domain.Translation
	calls int
	mu    sync.Mutex
}

func newDummyTranslationRepo() *dummyTranslationRepo {
	return &dummyTranslationRepo{store: map[uint]*domain.Translation{}}
}
func (d *dummyTranslationRepo) Create(_ context.Context, entity *domain.Translation) error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.calls++
	d.store[entity.ID] = entity
	return nil
}
func (d *dummyTranslationRepo) CreateInTx(_ context.Context, tx *gorm.DB, entity *domain.Translation) error {
	return errors.New("not implemented")
}
func (d *dummyTranslationRepo) GetByID(_ context.Context, id uuid.UUID) (*domain.Translation, error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.calls++
	tr, ok := d.store[id]
	if !ok {
		return nil, errors.New("not found")
	}
	cp := *tr
	return &cp, nil
}
func (d *dummyTranslationRepo) GetByIDWithOptions(_ context.Context, id uint, options *domain.QueryOptions) (*domain.Translation, error) {
	return d.GetByID(context.Background(), id)
}
func (d *dummyTranslationRepo) Update(_ context.Context, entity *domain.Translation) error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.calls++
	if _, ok := d.store[entity.ID]; !ok {
		return errors.New("not found")
	}
	d.store[entity.ID] = entity
	return nil
}
func (d *dummyTranslationRepo) UpdateInTx(_ context.Context, tx *gorm.DB, entity *domain.Translation) error {
	return errors.New("not implemented")
}
func (d *dummyTranslationRepo) Delete(_ context.Context, id uint) error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.calls++
	if _, ok := d.store[id]; !ok {
		return errors.New("not found")
	}
	delete(d.store, id)
	return nil
}
func (d *dummyTranslationRepo) DeleteInTx(_ context.Context, tx *gorm.DB, id uint) error {
	return errors.New("not implemented")
}
func (d *dummyTranslationRepo) List(_ context.Context, page, pageSize int) (*domain.PaginatedResult[domain.Translation], error) {
	return &domain.PaginatedResult[domain.Translation]{Items: []domain.Translation{}}, nil
}
func (d *dummyTranslationRepo) ListWithOptions(_ context.Context, options *domain.QueryOptions) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) ListAll(_ context.Context) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) Count(_ context.Context) (int64, error) { return 0, nil }
func (d *dummyTranslationRepo) CountWithOptions(_ context.Context, options *domain.QueryOptions) (int64, error) {
	return 0, nil
}
func (d *dummyTranslationRepo) FindWithPreload(_ context.Context, preloads []string, id uint) (*domain.Translation, error) {
	return d.GetByID(context.Background(), id)
}
func (d *dummyTranslationRepo) GetAllForSync(_ context.Context, batchSize, offset int) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) Exists(_ context.Context, id uint) (bool, error) {
	_, ok := d.store[id]
	return ok, nil
}
func (d *dummyTranslationRepo) BeginTx(_ context.Context) (*gorm.DB, error) { return nil, nil }
func (d *dummyTranslationRepo) WithTx(_ context.Context, fn func(tx *gorm.DB) error) error {
	return fn(nil)
}
func (d *dummyTranslationRepo) ListByWorkID(_ context.Context, workID uint) ([]domain.Translation, error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.calls++
	res := []domain.Translation{}
	for _, v := range d.store {
		if v.TranslatableID == workID {
			res = append(res, *v)
		}
	}
	return res, nil
}
func (d *dummyTranslationRepo) ListByWorkIDPaginated(_ context.Context, workID uint, language *string, page, pageSize int) (*domain.PaginatedResult[domain.Translation], error) {
	all, _ := d.ListByWorkID(context.Background(), workID)
	return &domain.PaginatedResult[domain.Translation]{Items: all, TotalCount: int64(len(all)), Page: page, PageSize: pageSize}, nil
}
func (d *dummyTranslationRepo) ListByEntity(_ context.Context, entityType string, entityID uint) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) ListByTranslatorID(_ context.Context, translatorID uint) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) ListByStatus(_ context.Context, status domain.TranslationStatus) ([]domain.Translation, error) {
	return nil, nil
}
func (d *dummyTranslationRepo) Upsert(_ context.Context, translation *domain.Translation) error {
	d.mu.Lock()
	defer d.mu.Unlock()
	if translation.ID == 0 {
		translation.ID = uint(len(d.store) + 1)
	}
	d.store[translation.ID] = translation
	d.calls++
	return nil
}

func TestCachedTranslation_GetByID_Caches(t *testing.T) {
	ctx := context.Background()
	d := newDummyTranslationRepo()
	d.store[1] = &domain.Translation{BaseModel: domain.BaseModel{ID: 1}, TranslatableID: 10, Language: "en", Title: "T1"}
	mc := newMemCacheT()
	ct := NewCachedTranslationRepository(d, mc, nil)

	tr, err := ct.GetByID(ctx, 1)
	require.NoError(t, err)
	require.Equal(t, "T1", tr.Title)
	require.Equal(t, 1, d.calls)

	// second read should hit cache
	tr2, err := ct.GetByID(ctx, 1)
	require.NoError(t, err)
	require.Equal(t, "T1", tr2.Title)
	require.Equal(t, 1, d.calls)
}

func TestCachedTranslation_ListByWorkID_Caches(t *testing.T) {
	ctx := context.Background()
	d := newDummyTranslationRepo()
	d.store[11] = &domain.Translation{BaseModel: domain.BaseModel{ID: 11}, TranslatableID: 100, Language: "en", Title: "A"}
	d.store[12] = &domain.Translation{BaseModel: domain.BaseModel{ID: 12}, TranslatableID: 100, Language: "fr", Title: "B"}
	mc := newMemCacheT()
	ct := NewCachedTranslationRepository(d, mc, nil)

	list, err := ct.ListByWorkID(ctx, 100)
	require.NoError(t, err)
	require.Len(t, list, 2)
	require.Equal(t, 1, d.calls)

	// second call should hit cache
	list2, err := ct.ListByWorkID(ctx, 100)
	require.NoError(t, err)
	require.Len(t, list2, 2)
	require.Equal(t, 1, d.calls)
}

func TestCachedTranslation_Update_Invalidates(t *testing.T) {
	ctx := context.Background()
	d := newDummyTranslationRepo()
	d.store[1] = &domain.Translation{BaseModel: domain.BaseModel{ID: 1}, TranslatableID: 10, Language: "en", Title: "Old"}
	mc := newMemCacheT()
	ct := NewCachedTranslationRepository(d, mc, nil)

	_, err := ct.GetByID(ctx, 1)
	require.NoError(t, err)

	// update underlying
	d.store[1] = &domain.Translation{BaseModel: domain.BaseModel{ID: 1}, TranslatableID: 10, Language: "en", Title: "New"}
	err = ct.Update(ctx, d.store[1])
	require.NoError(t, err)

	tr, err := ct.GetByID(ctx, 1)
	require.NoError(t, err)
	require.Equal(t, "New", tr.Title)
	require.Equal(t, 3, d.calls)
}