package httpapi_test

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

	httpapi "watch-party-backend/internal/http"
	"watch-party-backend/internal/repo"
	"watch-party-backend/internal/service"

	"github.com/gin-gonic/gin"
)

// ---- fake service implementing service.EpisodeService ----

type fakeSvc struct {
	cur       repo.Episode
	getErr    error
	setCur    repo.Episode
	setErr    error
	moveRes   repo.MoveResult
	moveErr   error
	lastSetID int64
	lastTime  string
	lastMove  []int64
}

func (f *fakeSvc) GetCurrent(ctx context.Context) (repo.Episode, error) {
	return f.cur, f.getErr
}
func (f *fakeSvc) SetCurrent(ctx context.Context, id int64, start string) (repo.Episode, error) {
	f.lastSetID, f.lastTime = id, start
	return f.setCur, f.setErr
}
func (f *fakeSvc) MoveToArchive(ctx context.Context, ids []int64) (repo.MoveResult, error) {
	f.lastMove = append([]int64(nil), ids...)
	return f.moveRes, f.moveErr
}
func (f *fakeSvc) ListAll(ctx context.Context) ([]repo.Episode, error) {
	if f.moveErr != nil {
		return nil, f.moveErr
	}
	return []repo.Episode{
		{Id: 10, EpTitle: "X"},
	}, nil
}

// ---- helpers ----

func newRouterWithSvc(svc service.EpisodeService) *gin.Engine {
	gin.SetMode(gin.TestMode)
	return httpapi.NewRouter(svc)
}

func doJSON(t *testing.T, r *gin.Engine, method, path string, body any) *httptest.ResponseRecorder {
	t.Helper()
	var buf bytes.Buffer
	if body != nil {
		if err := json.NewEncoder(&buf).Encode(body); err != nil {
			t.Fatalf("encode body: %v", err)
		}
	}
	req := httptest.NewRequest(method, path, &buf)
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)
	return w
}

// ---- tests ----

func TestHealthz_OK(t *testing.T) {
	r := newRouterWithSvc(&fakeSvc{})
	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
	r.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("got %d", w.Code)
	}
}

func TestGetCurrent_V1_OK(t *testing.T) {
	now := time.Now().UTC()
	svc := &fakeSvc{
		cur: repo.Episode{
			EpNum:          7,
			EpTitle:        "Lucky",
			SeasonName:     "S2",
			StartTime:      "18:30:00",
			PlaybackLength: "00:24:00",
			DateCreated:    now,
		},
	}
	r := newRouterWithSvc(svc)

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/v1/current", nil)
	r.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("got %d", w.Code)
	}
	var got repo.Episode
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("json: %v", err)
	}
	if got.EpNum != 7 || got.EpTitle != "Lucky" {
		t.Fatalf("unexpected %+v", got)
	}
}

func TestPostCurrent_BadPayload(t *testing.T) {
	r := newRouterWithSvc(&fakeSvc{})
	// missing fields
	w := doJSON(t, r, http.MethodPost, "/v1/current", map[string]any{"id": 1})
	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d", w.Code)
	}
}

func TestPostCurrent_BadTime(t *testing.T) {
	svc := &fakeSvc{setErr: service.ErrInvalidTime}
	r := newRouterWithSvc(svc)
	w := doJSON(t, r, http.MethodPost, "/v1/current", map[string]any{
		"id": 42, "start_time": "7:0:0",
	})
	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d; body=%s", w.Code, w.Body.String())
	}
}

func TestPostCurrent_OK(t *testing.T) {
	want := repo.Episode{EpNum: 42, EpTitle: "Answer", StartTime: "21:07:05"}
	svc := &fakeSvc{setCur: want}
	r := newRouterWithSvc(svc)
	w := doJSON(t, r, http.MethodPost, "/v1/current", map[string]any{
		"id": 42, "start_time": "21:07:05",
	})
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d; body=%s", w.Code, w.Body.String())
	}
	var got repo.Episode
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("json: %v", err)
	}
	if got.EpNum != want.EpNum || got.StartTime != want.StartTime {
		t.Fatalf("unexpected %+v", got)
	}
	if svc.lastSetID != 42 || svc.lastTime != "21:07:05" {
		t.Fatalf("service not called as expected: id=%d time=%s", svc.lastSetID, svc.lastTime)
	}
}

func TestPostArchive_Empty(t *testing.T) {
	svc := &fakeSvc{moveErr: service.ErrEmptyIDs}
	r := newRouterWithSvc(svc)
	w := doJSON(t, r, http.MethodPost, "/v1/archive", map[string]any{})
	if w.Code != http.StatusBadRequest {
		t.Fatalf("expected 400, got %d; body=%s", w.Code, w.Body.String())
	}
}

func TestPostArchive_SingleAndMultiple_OK(t *testing.T) {
	svc := &fakeSvc{
		moveRes: repo.MoveResult{
			MovedIDs:   []int64{1, 2},
			DeletedIDs: []int64{1, 2},
			SkippedIDs: []int64{999},
		},
	}
	r := newRouterWithSvc(svc)

	// single
	w1 := doJSON(t, r, http.MethodPost, "/v1/archive", map[string]any{"id": 1})
	if w1.Code != http.StatusOK {
		t.Fatalf("got %d: %s", w1.Code, w1.Body.String())
	}
	// multiple
	w2 := doJSON(t, r, http.MethodPost, "/v1/archive", map[string]any{"ids": []int64{1, 2, 1}})
	if w2.Code != http.StatusOK {
		t.Fatalf("got %d: %s", w2.Code, w2.Body.String())
	}
	// check the lastMove captured by fake
	if len(svc.lastMove) != 3 || svc.lastMove[0] != 1 || svc.lastMove[1] != 2 {
		t.Fatalf("unexpected service ids: %+v", svc.lastMove)
	}
	// basic JSON fields present
	var body map[string]any
	if err := json.Unmarshal(w2.Body.Bytes(), &body); err != nil {
		t.Fatalf("json: %v", err)
	}
	if body["inserted"] == nil || body["deleted"] == nil {
		t.Fatalf("missing counters in response: %+v", body)
	}
}