package api

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

	"github.com/go-chi/chi/v5"
	"github.com/jackc/pgx/v5/pgtype"

	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
)

// newRequestsRouter builds a test chi router wiring the /api/requests handlers
// with chi URL params but without RequireUser middleware. Tests inject a user
// into the context manually.
func newRequestsRouter(h *handlers) chi.Router {
	r := chi.NewRouter()
	r.Post("/api/requests", h.handleCreateRequest)
	r.Get("/api/requests", h.handleListRequests)
	r.Get("/api/requests/{id}", h.handleGetRequest)
	r.Delete("/api/requests/{id}", h.handleCancelRequest)
	return r
}

// withUser injects a user into the request context the same way RequireUser does.
func withUser(req *http.Request, user dbq.User) *http.Request {
	return req.WithContext(context.WithValue(req.Context(), userCtxKeyForTest(), user))
}

// doCreateRequest fires POST /api/requests with the given JSON body as the given user.
func doCreateRequest(h *handlers, user dbq.User, body string) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodPost, "/api/requests", bytes.NewBufferString(body))
	req.Header.Set("Content-Type", "application/json")
	req = withUser(req, user)
	w := httptest.NewRecorder()
	newRequestsRouter(h).ServeHTTP(w, req)
	return w
}

// doListRequests fires GET /api/requests as the given user.
func doListRequests(h *handlers, user dbq.User) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodGet, "/api/requests", nil)
	req = withUser(req, user)
	w := httptest.NewRecorder()
	newRequestsRouter(h).ServeHTTP(w, req)
	return w
}

// doGetRequest fires GET /api/requests/:id as the given user.
func doGetRequest(h *handlers, user dbq.User, id pgtype.UUID) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodGet, "/api/requests/"+uuidToString(id), nil)
	req = withUser(req, user)
	w := httptest.NewRecorder()
	newRequestsRouter(h).ServeHTTP(w, req)
	return w
}

// doCancelRequest fires DELETE /api/requests/:id as the given user.
func doCancelRequest(h *handlers, user dbq.User, id pgtype.UUID) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodDelete, "/api/requests/"+uuidToString(id), nil)
	req = withUser(req, user)
	w := httptest.NewRecorder()
	newRequestsRouter(h).ServeHTTP(w, req)
	return w
}

// createArtistRequest is a convenience wrapper that seeds a valid artist request
// via the handler and returns the parsed response.
func createArtistRequest(t *testing.T, h *handlers, user dbq.User, artistMBID, artistName string) requestView {
	t.Helper()
	body := fmt.Sprintf(`{"kind":"artist","lidarr_artist_mbid":%q,"artist_name":%q}`, artistMBID, artistName)
	w := doCreateRequest(h, user, body)
	if w.Code != http.StatusCreated {
		t.Fatalf("createArtistRequest: status = %d, want 201; body = %s", w.Code, w.Body.String())
	}
	var rv requestView
	if err := json.Unmarshal(w.Body.Bytes(), &rv); err != nil {
		t.Fatalf("createArtistRequest: decode: %v; body = %s", err, w.Body.String())
	}
	return rv
}

// TestHandleCreateRequest_AutoApprove_LidarrDisabled_StaysPending verifies
// that a user with auto_approve_requests=true still receives a 201 Created
// when Lidarr is disabled in the test environment — the auto-approve attempt
// fails inside Service.Approve with ErrLidarrDisabled, which the handler
// catches and logs, leaving the row in pending state. This is the U2.5
// fallback contract: a misconfigured Lidarr must not break request creation.
func TestHandleCreateRequest_AutoApprove_LidarrDisabled_StaysPending(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	if _, err := pool.Exec(context.Background(),
		"UPDATE users SET auto_approve_requests = true WHERE id = $1", alice.ID); err != nil {
		t.Fatalf("set auto_approve: %v", err)
	}
	// Re-fetch so the User row carried into the request context has the flag.
	refreshed, err := dbq.New(pool).GetUserByID(context.Background(), alice.ID)
	if err != nil {
		t.Fatalf("reload user: %v", err)
	}
	if !refreshed.AutoApproveRequests {
		t.Fatalf("auto_approve flag did not persist — bailing")
	}

	body := `{"kind":"artist","lidarr_artist_mbid":"auto-mbid-1","artist_name":"Autoband"}`
	w := doCreateRequest(h, refreshed, body)

	if w.Code != http.StatusCreated {
		t.Fatalf("status = %d, want 201; body = %s", w.Code, w.Body.String())
	}
	var rv requestView
	if err := json.Unmarshal(w.Body.Bytes(), &rv); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if rv.Status != "pending" {
		t.Errorf("status = %q, want pending (auto-approve falls back when Lidarr disabled)", rv.Status)
	}
}

// TestHandleCreateRequest_Artist_HappyPath verifies a valid artist request
// returns 201 with kind=artist and status=pending.
func TestHandleCreateRequest_Artist_HappyPath(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	body := `{"kind":"artist","lidarr_artist_mbid":"artist-mbid-1","artist_name":"The Beatles"}`
	w := doCreateRequest(h, alice, body)

	if w.Code != http.StatusCreated {
		t.Fatalf("status = %d, want 201; body = %s", w.Code, w.Body.String())
	}
	var rv requestView
	if err := json.Unmarshal(w.Body.Bytes(), &rv); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if string(rv.Kind) != "artist" {
		t.Errorf("kind = %q, want artist", rv.Kind)
	}
	if rv.Status != "pending" {
		t.Errorf("status = %q, want pending", rv.Status)
	}
	if rv.LidarrArtistMBID != "artist-mbid-1" {
		t.Errorf("lidarr_artist_mbid = %q", rv.LidarrArtistMBID)
	}
	if rv.ArtistName != "The Beatles" {
		t.Errorf("artist_name = %q", rv.ArtistName)
	}
	if !rv.ID.Valid {
		t.Error("id not set")
	}
}

// TestHandleCreateRequest_AlbumWithoutAlbumMBID_400 verifies that sending
// kind=album without lidarr_album_mbid returns 400 with mbid_required.
func TestHandleCreateRequest_AlbumWithoutAlbumMBID_400(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	// Missing lidarr_album_mbid and album_title.
	body := `{"kind":"album","lidarr_artist_mbid":"artist-mbid-1","artist_name":"The Beatles"}`
	w := doCreateRequest(h, alice, body)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want 400; body = %s", w.Code, w.Body.String())
	}
	var resp struct {
		Error struct {
			Code string `json:"code"`
		} `json:"error"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if resp.Error.Code != "mbid_required" {
		t.Errorf("error.code = %q, want mbid_required", resp.Error.Code)
	}
}

// TestHandleCreateRequest_TrackWithoutTrackFields_400 verifies that kind=track
// with missing track_mbid/track_title returns 400 with mbid_required.
func TestHandleCreateRequest_TrackWithoutTrackFields_400(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	// Provides album fields but misses track_mbid and track_title.
	body := `{"kind":"track","lidarr_artist_mbid":"artist-mbid-1","artist_name":"Beatles","lidarr_album_mbid":"album-mbid-1","album_title":"Abbey Road"}`
	w := doCreateRequest(h, alice, body)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want 400; body = %s", w.Code, w.Body.String())
	}
	var resp struct {
		Error struct {
			Code string `json:"code"`
		} `json:"error"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if resp.Error.Code != "mbid_required" {
		t.Errorf("error.code = %q, want mbid_required", resp.Error.Code)
	}
}

// TestHandleListRequests_OnlyOwnRequests verifies alice sees only her own
// requests, not bob's.
func TestHandleListRequests_OnlyOwnRequests(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	bob := seedUser(t, pool, "bob", "pw", false)

	createArtistRequest(t, h, alice, "alice-mbid-1", "Alice Artist 1")
	createArtistRequest(t, h, alice, "alice-mbid-2", "Alice Artist 2")
	createArtistRequest(t, h, bob, "bob-mbid-1", "Bob Artist 1")

	w := doListRequests(h, alice)
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", w.Code, w.Body.String())
	}
	var results []requestView
	if err := json.Unmarshal(w.Body.Bytes(), &results); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if len(results) != 2 {
		t.Fatalf("len(results) = %d, want 2", len(results))
	}
	for _, rv := range results {
		if rv.UserID != alice.ID {
			t.Errorf("result belongs to wrong user: %v", rv.UserID)
		}
	}
}

// TestHandleGetRequest_OwnReturns200 verifies a caller can fetch their own request.
func TestHandleGetRequest_OwnReturns200(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	rv := createArtistRequest(t, h, alice, "artist-mbid-get", "Get Artist")

	w := doGetRequest(h, alice, rv.ID)
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", w.Code, w.Body.String())
	}
	var got requestView
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if got.ID != rv.ID {
		t.Errorf("id mismatch")
	}
}

// TestHandleGetRequest_OtherUserNotAdmin_404 verifies a non-admin caller
// cannot see another user's request.
func TestHandleGetRequest_OtherUserNotAdmin_404(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	bob := seedUser(t, pool, "bob", "pw", false)
	charlie := seedUser(t, pool, "charlie", "pw", false)

	rv := createArtistRequest(t, h, bob, "bob-artist-mbid", "Bob's Artist")

	// Charlie is not an admin, tries to fetch Bob's request.
	w := doGetRequest(h, charlie, rv.ID)
	if w.Code != http.StatusNotFound {
		t.Fatalf("status = %d, want 404; body = %s", w.Code, w.Body.String())
	}
	var resp struct {
		Error struct {
			Code string `json:"code"`
		} `json:"error"`
	}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if resp.Error.Code != "request_not_found" {
		t.Errorf("error.code = %q, want request_not_found", resp.Error.Code)
	}
}

// TestHandleGetRequest_OtherUserAsAdmin_200 verifies an admin can fetch any
// user's request.
func TestHandleGetRequest_OtherUserAsAdmin_200(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	bob := seedUser(t, pool, "bob", "pw", false)
	admin := seedUser(t, pool, "admin", "pw", true)

	rv := createArtistRequest(t, h, bob, "bob-admin-mbid", "Bob's Artist For Admin")

	// Admin fetches Bob's request — should succeed.
	w := doGetRequest(h, admin, rv.ID)
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", w.Code, w.Body.String())
	}
	var got requestView
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if got.ID != rv.ID {
		t.Errorf("id mismatch")
	}
}

// TestHandleCancelRequest_PendingHappyPath verifies that cancelling a pending
// request returns 200 with status=rejected.
func TestHandleCancelRequest_PendingHappyPath(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	rv := createArtistRequest(t, h, alice, "cancel-mbid-1", "Cancel Me")

	w := doCancelRequest(h, alice, rv.ID)
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body = %s", w.Code, w.Body.String())
	}
	var got requestView
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w.Body.String())
	}
	if got.Status != "rejected" {
		t.Errorf("status = %q, want rejected", got.Status)
	}
}

// TestHandleCancelRequest_NonPending_409 verifies that cancelling an already
// rejected request returns 409 with request_not_pending.
func TestHandleCancelRequest_NonPending_409(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice", "pw", false)
	rv := createArtistRequest(t, h, alice, "cancel-mbid-2", "Cancel Twice")

	// First cancel transitions to rejected.
	w1 := doCancelRequest(h, alice, rv.ID)
	if w1.Code != http.StatusOK {
		t.Fatalf("first cancel: status = %d, want 200; body = %s", w1.Code, w1.Body.String())
	}

	// Second cancel on a now-rejected row → ErrNotPending → 409.
	// The cancel SQL checks user_id = $2 AND status = 'pending'; zero rows → ErrNotPending.
	// For this test we use dbq directly to reject via admin so Cancel returns ErrNotPending
	// rather than the ownership miss. We already did first cancel so row is rejected.
	w2 := doCancelRequest(h, alice, rv.ID)
	if w2.Code != http.StatusConflict {
		t.Fatalf("second cancel: status = %d, want 409; body = %s", w2.Code, w2.Body.String())
	}
	var resp struct {
		Error struct {
			Code string `json:"code"`
		} `json:"error"`
	}
	if err := json.Unmarshal(w2.Body.Bytes(), &resp); err != nil {
		t.Fatalf("decode: %v; body = %s", err, w2.Body.String())
	}
	if resp.Error.Code != "request_not_pending" {
		t.Errorf("error.code = %q, want request_not_pending", resp.Error.Code)
	}
}

// TestHandleCancelRequest_WrongUser_409 verifies that attempting to cancel
// another user's request returns 409 (not_pending from the ownership miss).
func TestHandleCancelRequest_WrongUser_409(t *testing.T) {
	h, pool := testHandlers(t)
	resetLidarrState(t, h)

	alice := seedUser(t, pool, "alice-cancel-owner", "pw", false)
	bob := seedUser(t, pool, "bob-cancel-other", "pw", false)

	rv := createArtistRequest(t, h, alice, "cancel-wrong-user-mbid", "Alice's Artist")

	// Bob tries to cancel Alice's request: SQL WHERE user_id=bob AND status=pending → 0 rows.
	w := doCancelRequest(h, bob, rv.ID)
	if w.Code != http.StatusConflict {
		t.Fatalf("status = %d, want 409; body = %s", w.Code, w.Body.String())
	}
}