package test

import (
	"RenewCMS/api"
	"RenewCMS/internal/domain/article"
	"RenewCMS/internal/domain/author"
	"RenewCMS/internal/domain/user"
	"RenewCMS/internal/infrastructure/useCases"
	"encoding/json"
	"io"
	"log"
	"net/http/httptest"
	"sort"
	"strings"
	"testing"
	"time"

	"github.com/go-chi/chi/v5"
)

type authorDeleteCall struct {
	id         uint32
	reassignTo *uint32
}

type mockAuthorRepo struct {
	authors     map[uint32]author.Author
	articles    *mockArticleRepo
	nextID      uint32
	fail        failSwitch
	createCalls int
	deleteCalls []authorDeleteCall
}

func newMockAuthorRepo(articles *mockArticleRepo) *mockAuthorRepo {
	repo := &mockAuthorRepo{authors: map[uint32]author.Author{}, articles: articles}
	articles.authors = repo
	return repo
}

func plainAuthors() *mockAuthorRepo {
	return newMockAuthorRepo(newMockArticleRepo())
}

func (m *mockAuthorRepo) seed(id uint32, name string, slug string) author.Author {
	seeded := author.Author{ID: id, Name: name, Slug: slug, SocialLinks: []author.SocialLink{}}
	m.authors[id] = seeded
	if id > m.nextID {
		m.nextID = id
	}
	return seeded
}

func (m *mockAuthorRepo) seedLinked(id uint32, name string, slug string, userID uint32) author.Author {
	seeded := m.seed(id, name, slug)
	seeded.UserID = idPointer(userID)
	seeded.IsLinked = true
	m.authors[id] = seeded
	return seeded
}

func (m *mockAuthorRepo) update(id uint32, change func(*author.Author)) {
	found := m.authors[id]
	change(&found)
	m.authors[id] = found
}

func (m *mockAuthorRepo) withCount(a author.Author) author.Author {
	a.ArticleCount = 0
	for articleID, ids := range m.articles.credits {
		if _, exists := m.articles.articles[articleID]; !exists {
			continue
		}
		for _, id := range ids {
			if id == a.ID {
				a.ArticleCount++
			}
		}
	}
	a.IsLinked = a.UserID != nil
	return a
}

func (m *mockAuthorRepo) snapshot() map[uint32]author.Author {
	copied := make(map[uint32]author.Author, len(m.authors))
	for id, a := range m.authors {
		copied[id] = m.withCount(a)
	}
	return copied
}

func (m *mockAuthorRepo) sortedIDsDescending() []uint32 {
	ids := make([]uint32, 0, len(m.authors))
	for id := range m.authors {
		ids = append(ids, id)
	}
	sort.Slice(ids, func(i, j int) bool { return ids[i] > ids[j] })
	return ids
}

func (m *mockAuthorRepo) List(query author.ListQuery) (author.Page, error) {
	if err := m.fail.trigger("List"); err != nil {
		return author.Page{}, err
	}
	needle := foldArticleSearch(strings.TrimSpace(query.Q))
	matching := []author.Author{}
	for _, id := range m.sortedIDsDescending() {
		a := m.authors[id]
		if needle != "" && !strings.Contains(foldArticleSearch(a.Name), needle) && !strings.Contains(foldArticleSearch(a.Slug), needle) {
			continue
		}
		matching = append(matching, m.withCount(a))
	}
	start := len(matching)
	if query.Size > 0 && query.Page-1 <= len(matching)/query.Size {
		start = min((query.Page-1)*query.Size, len(matching))
	}
	end := min(start+query.Size, len(matching))
	return author.Page{Items: matching[start:end], Total: len(matching)}, nil
}

func (m *mockAuthorRepo) Get(id uint32) (author.Author, error) {
	if err := m.fail.trigger("Get"); err != nil {
		return author.Author{}, err
	}
	found, ok := m.authors[id]
	if !ok {
		return author.Author{}, author.ErrAuthorNotFound
	}
	return m.withCount(found), nil
}

func (m *mockAuthorRepo) GetBySlug(slug string) (author.Author, error) {
	if err := m.fail.trigger("GetBySlug"); err != nil {
		return author.Author{}, err
	}
	for _, a := range m.authors {
		if a.Slug == slug {
			return m.withCount(a), nil
		}
	}
	return author.Author{}, author.ErrAuthorNotFound
}

func (m *mockAuthorRepo) GetByUserID(userID uint32) (author.Author, error) {
	if err := m.fail.trigger("GetByUserID"); err != nil {
		return author.Author{}, err
	}
	for _, a := range m.authors {
		if a.UserID != nil && *a.UserID == userID {
			return m.withCount(a), nil
		}
	}
	return author.Author{}, author.ErrAuthorNotFound
}

func (m *mockAuthorRepo) conflictFor(candidate author.Author) error {
	for _, a := range m.authors {
		if a.ID == candidate.ID {
			continue
		}
		if a.Slug == candidate.Slug {
			return author.ErrSlugTaken
		}
		if candidate.UserID != nil && a.UserID != nil && *a.UserID == *candidate.UserID {
			return author.ErrUserAlreadyLinked
		}
	}
	return nil
}

func (m *mockAuthorRepo) Create(a author.Author) (author.Author, error) {
	m.createCalls++
	if err := m.fail.trigger("Create"); err != nil {
		return author.Author{}, err
	}
	a.ID = 0
	if err := m.conflictFor(a); err != nil {
		return author.Author{}, err
	}
	m.nextID++
	a.ID = m.nextID
	a.IsLinked = a.UserID != nil
	m.authors[a.ID] = a
	return m.withCount(a), nil
}

func (m *mockAuthorRepo) Update(a author.Author) (author.Author, error) {
	if err := m.fail.trigger("Update"); err != nil {
		return author.Author{}, err
	}
	if _, ok := m.authors[a.ID]; !ok {
		return author.Author{}, author.ErrAuthorNotFound
	}
	if err := m.conflictFor(a); err != nil {
		return author.Author{}, err
	}
	a.UserEmail = nil
	m.authors[a.ID] = a
	return m.withCount(a), nil
}

func (m *mockAuthorRepo) DeleteMovingCredits(id uint32, reassignTo *uint32) error {
	m.deleteCalls = append(m.deleteCalls, authorDeleteCall{id: id, reassignTo: reassignTo})
	if err := m.fail.trigger("DeleteMovingCredits"); err != nil {
		return err
	}
	if _, ok := m.authors[id]; !ok {
		return author.ErrAuthorNotFound
	}
	if reassignTo == nil && m.creditCount(id) > 0 {
		return author.ErrAuthorHasArticles
	}
	if reassignTo != nil {
		if _, ok := m.authors[*reassignTo]; !ok {
			return author.ErrAuthorNotFound
		}
	}
	m.removeWithCredits(id, reassignTo)
	return nil
}

func (m *mockAuthorRepo) DeleteUncrediting(id uint32) error {
	m.deleteCalls = append(m.deleteCalls, authorDeleteCall{id: id})
	if err := m.fail.trigger("DeleteMovingCredits"); err != nil {
		return err
	}
	if _, ok := m.authors[id]; !ok {
		return author.ErrAuthorNotFound
	}
	m.removeWithCredits(id, nil)
	return nil
}

func (m *mockAuthorRepo) creditCount(id uint32) int {
	total := 0
	for _, ids := range m.articles.credits {
		if containsID(ids, id) {
			total++
		}
	}
	return total
}

func (m *mockAuthorRepo) removeWithCredits(id uint32, reassignTo *uint32) {
	for articleID, ids := range m.articles.credits {
		m.articles.credits[articleID] = replaceCredit(ids, id, reassignTo)
	}
	delete(m.authors, id)
}

func replaceCredit(ids []uint32, from uint32, to *uint32) []uint32 {
	result := []uint32{}
	for _, id := range ids {
		if id != from {
			result = append(result, id)
			continue
		}
		if to != nil && !containsID(ids, *to) {
			result = append(result, *to)
		}
	}
	return result
}

func containsID(ids []uint32, wanted uint32) bool {
	for _, id := range ids {
		if id == wanted {
			return true
		}
	}
	return false
}

func (m *mockAuthorRepo) AvatarUsage() (map[uint32]int, error) {
	usage := map[uint32]int{}
	for _, a := range m.authors {
		if a.AvatarID != nil {
			usage[*a.AvatarID]++
		}
	}
	return usage, nil
}

func (m *mockAuthorRepo) ClearAvatar(imageID uint32) ([]uint32, error) {
	cleared := []uint32{}
	for _, id := range m.sortedIDsDescending() {
		a := m.authors[id]
		if a.AvatarID != nil && *a.AvatarID == imageID {
			a.AvatarID = nil
			m.authors[id] = a
			cleared = append(cleared, id)
		}
	}
	return cleared, nil
}

func (m *mockAuthorRepo) AssignAvatar(authorIDs []uint32, imageID uint32) error {
	for _, id := range authorIDs {
		a := m.authors[id]
		a.AvatarID = idPointer(imageID)
		m.authors[id] = a
	}
	return nil
}

func (m *mockAuthorRepo) RepointAvatar(fromImageIDs []uint32, toImageID uint32) (int, error) {
	changed := 0
	for id, a := range m.authors {
		if a.AvatarID != nil && containsID(fromImageIDs, *a.AvatarID) {
			a.AvatarID = idPointer(toImageID)
			m.authors[id] = a
			changed++
		}
	}
	return changed, nil
}

var _ author.Repository = &mockAuthorRepo{}

const (
	authorEditorID      = 5
	authorOtherEditorID = 6
	authorEditorRole    = user.Role("editor")
)

type authorEnv struct {
	*producersEnv
	authors *mockAuthorRepo
}

func newAuthorEnv(t *testing.T) *authorEnv {
	t.Helper()
	p := newProducersEnv(t)
	p.users.users[authorEditorID] = user.User{ID: authorEditorID, Username: "edith", DisplayName: "Edith Moreau", Email: "edith@example.com", IsVerified: true, Role: authorEditorRole}
	p.users.users[authorOtherEditorID] = user.User{ID: authorOtherEditorID, Username: "frank", Email: "frank@example.com", IsVerified: true, Role: authorEditorRole}
	p.users.nextID = authorOtherEditorID
	authors := newMockAuthorRepo(p.articles)
	sites := plainSites()
	recorder := p.audit.recorder
	renderer := &fakeBodyRenderer{}
	mergeMedia := useCases.NewMergeMediaUseCase(p.images, p.articles, newMockImageStorage(), newMockVariantFileRepo(), recorder, sites, authors)
	c := p.container
	c.CreateArticleUseCase = useCases.NewCreateArticleUseCase(p.articles, renderer, recorder, sites, authors)
	c.UpdateArticleUseCase = useCases.NewUpdateArticleUseCase(p.articles, renderer, recorder, sites, authors)
	c.ListMediaUseCase = useCases.NewListMediaUseCase(p.images, p.articles, p.users, newMockVariantFileRepo(), sites, authors)
	c.DeleteMediaUseCase = useCases.NewDeleteMediaUseCase(p.images, newMockImageStorage(), newMockVariantFileRepo(), recorder, sites, authors)
	c.MergeMediaUseCase = mergeMedia
	c.RunPurgeUseCase = useCases.NewRunPurgeUseCase(p.images, p.articles, mergeMedia, newMockPurgeSettingsRepo(), func() time.Time { return p.now }, log.New(io.Discard, "", 0), recorder, sites, authors)
	c.ListActivityUseCase = useCases.NewListActivityUseCase(p.audit.store, p.users, p.articles, p.images, p.keys, p.audit.clock, sites, authors)
	c.ListAuthorsUseCase = useCases.NewListAuthorsUseCase(authors, p.users)
	c.CreateAuthorUseCase = useCases.NewCreateAuthorUseCase(authors, p.users, p.images, recorder)
	c.CreateMyAuthorUseCase = useCases.NewCreateMyAuthorUseCase(authors, p.users, recorder)
	c.UpdateAuthorUseCase = useCases.NewUpdateAuthorUseCase(authors, p.users, p.images, recorder)
	c.DeleteAuthorUseCase = useCases.NewDeleteAuthorUseCase(authors, recorder)
	c.GetMyAuthorUseCase = useCases.NewGetMyAuthorUseCase(authors)
	router := chi.NewRouter()
	router.Mount("/v1", api.InitBackendRoutes(c, p.settings))
	p.router = router
	return &authorEnv{producersEnv: p, authors: authors}
}

func (e *authorEnv) owner(t *testing.T, method string, path string, body string) *httptest.ResponseRecorder {
	t.Helper()
	return e.as(t, apiKeyOwnerId, method, path, body)
}

func (e *authorEnv) seedOnlineArticle(id uint32, title string, authorIDs ...uint32) {
	e.articles.articles[id] = article.Article{ID: id, Title: title, Body: "Body", IsOnline: true, SiteID: 1}
	e.articles.credit(id, authorIDs...)
}

func (e *authorEnv) seedOfflineArticle(id uint32, title string, authorIDs ...uint32) {
	e.articles.articles[id] = article.Article{ID: id, Title: title, Body: "Body", SiteID: 1}
	e.articles.credit(id, authorIDs...)
}

func (e *authorEnv) creditsOf(articleID uint32) []uint32 {
	return append([]uint32{}, e.articles.credits[articleID]...)
}

func decodeAuthorBody(t *testing.T, rec *httptest.ResponseRecorder) map[string]any {
	t.Helper()
	var decoded map[string]any
	if err := json.Unmarshal(rec.Body.Bytes(), &decoded); err != nil {
		t.Fatalf("decode %q: %v", rec.Body.String(), err)
	}
	return decoded
}

type authorListBody struct {
	Items []map[string]any `json:"items"`
	Total int              `json:"total"`
	Page  int              `json:"page"`
	Size  int              `json:"size"`
}

func decodeAuthorList(t *testing.T, rec *httptest.ResponseRecorder) authorListBody {
	t.Helper()
	var decoded authorListBody
	if err := json.Unmarshal(rec.Body.Bytes(), &decoded); err != nil {
		t.Fatalf("decode list %q: %v", rec.Body.String(), err)
	}
	return decoded
}

func listedNames(list authorListBody) []string {
	names := []string{}
	for _, item := range list.Items {
		names = append(names, item["name"].(string))
	}
	return names
}

func joinNames(names []string) string {
	return strings.Join(names, "|")
}

func userWithEmail(id uint32, username string, email string) user.User {
	return user.User{ID: id, Username: username, Email: email, IsVerified: true, Role: authorEditorRole}
}

func userNamed(id uint32, username string, displayName string) user.User {
	return user.User{ID: id, Username: username, DisplayName: displayName, Email: username + "@example.com", IsVerified: true, Role: authorEditorRole}
}