package mail

import (
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"

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

	"github.com/ultisuite/ulti-backend/internal/api/middleware"
	"github.com/ultisuite/ulti-backend/internal/api/query"
	"github.com/ultisuite/ulti-backend/internal/auth"
)

type draftFakeService struct {
	fakeMailService
	drafts  map[string]map[string]any
	created []draftRequest
	nextID  int
}

func newDraftFakeService() *draftFakeService {
	return &draftFakeService{
		fakeMailService: *newFakeMailService(),
		drafts: map[string]map[string]any{
			"draft-1": {
				"id": "draft-1", "account_id": "acc-1", "subject": "Draft subject",
				"body_text": "Draft body", "to": json.RawMessage(`[]`),
				"cc": json.RawMessage(`[]`), "bcc": json.RawMessage(`[]`),
			},
		},
	}
}

func (f *draftFakeService) ListDrafts(_ context.Context, externalID string, params query.ListParams) (DraftsList, error) {
	if externalID != testExternalID {
		return DraftsList{}, ErrUserNotProvisioned
	}
	drafts := make([]map[string]any, 0, len(f.drafts))
	for _, draft := range f.drafts {
		drafts = append(drafts, draft)
	}
	total := int64(len(drafts))
	return DraftsList{
		Drafts:     drafts,
		Pagination: params.Meta(&total),
	}, nil
}

func (f *draftFakeService) GetDraft(_ context.Context, externalID, draftID string) (map[string]any, error) {
	if externalID != testExternalID {
		return nil, ErrUserNotProvisioned
	}
	draft, ok := f.drafts[draftID]
	if !ok {
		return nil, ErrNotFound
	}
	return draft, nil
}

func (f *draftFakeService) CreateDraft(_ context.Context, userID string, req *draftRequest) (string, error) {
	if userID != testUserID {
		return "", ErrAccountNotFound
	}
	f.nextID++
	id := "draft-new"
	if f.nextID > 1 {
		id = "draft-new-2"
	}
	f.created = append(f.created, *req)
	f.drafts[id] = map[string]any{
		"id": id, "account_id": req.AccountID, "subject": req.Subject,
		"body_text": req.BodyText, "to": req.To,
	}
	return id, nil
}

func (f *draftFakeService) UpdateDraft(_ context.Context, externalID, draftID string, req *draftRequest) error {
	if externalID != testExternalID {
		return ErrNotFound
	}
	if _, ok := f.drafts[draftID]; !ok {
		return ErrNotFound
	}
	return nil
}

func (f *draftFakeService) DeleteDraft(_ context.Context, externalID, draftID string) error {
	if externalID != testExternalID {
		return ErrNotFound
	}
	if _, ok := f.drafts[draftID]; !ok {
		return ErrNotFound
	}
	delete(f.drafts, draftID)
	return nil
}

func newTestDraftsRouter(svc ServiceAPI) http.Handler {
	h := NewHandlerWithService(svc)
	r := chi.NewRouter()
	r.Use(middleware.WithTestClaims(&auth.Claims{
		Sub:   testExternalID,
		Email: "user@example.com",
	}))
	r.Get("/drafts", h.ListDrafts)
	r.Post("/drafts", h.CreateDraft)
	r.Get("/drafts/{draftID}", h.GetDraft)
	r.Put("/drafts/{draftID}", h.UpdateDraft)
	r.Delete("/drafts/{draftID}", h.DeleteDraft)
	return r
}

func TestListDrafts(t *testing.T) {
	svc := newDraftFakeService()
	router := newTestDraftsRouter(svc)

	req := httptest.NewRequest(http.MethodGet, "/drafts", nil)
	rec := httptest.NewRecorder()
	router.ServeHTTP(rec, req)

	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d; body = %s", rec.Code, http.StatusOK, rec.Body.String())
	}

	var body DraftsList
	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
		t.Fatalf("decode body: %v", err)
	}
	if len(body.Drafts) != 1 {
		t.Fatalf("drafts len = %d, want 1", len(body.Drafts))
	}
	if body.Drafts[0]["id"] != "draft-1" {
		t.Fatalf("draft id = %v", body.Drafts[0]["id"])
	}
}

func TestCreateDraft(t *testing.T) {
	svc := newDraftFakeService()
	router := newTestDraftsRouter(svc)

	payload := map[string]any{
		"account_id": "acc-1",
		"subject":    "New draft",
		"body_text":  "Hello draft",
	}
	body, err := json.Marshal(payload)
	if err != nil {
		t.Fatalf("marshal payload: %v", err)
	}

	req := httptest.NewRequest(http.MethodPost, "/drafts", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	rec := httptest.NewRecorder()
	router.ServeHTTP(rec, req)

	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want %d; body = %s", rec.Code, http.StatusCreated, rec.Body.String())
	}

	var resp map[string]string
	if err := json.NewDecoder(rec.Body).Decode(&resp); err != nil {
		t.Fatalf("decode body: %v", err)
	}
	if resp["id"] != "draft-new" {
		t.Fatalf("response id = %q", resp["id"])
	}
	if len(svc.created) != 1 {
		t.Fatalf("created count = %d, want 1", len(svc.created))
	}
	if svc.created[0].Subject != "New draft" {
		t.Fatalf("created subject = %q", svc.created[0].Subject)
	}
}