package api

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

func callRadio(h *handlers, user interface{}, query string) *httptest.ResponseRecorder {
	req := httptest.NewRequest(http.MethodGet, "/api/radio?"+query, nil)
	req = req.WithContext(context.WithValue(req.Context(), userCtxKeyForTest(), user))
	w := httptest.NewRecorder()
	h.handleRadio(w, req)
	return w
}

func TestHandleRadio_ColdStart_OnlySeedReturned(t *testing.T) {
	h, pool := testHandlers(t)
	truncateLibrary(t, pool)
	user := seedUser(t, pool, "alice", "x", false)
	artist := seedArtist(t, pool, "X")
	album := seedAlbum(t, pool, artist.ID, "X", 1990)
	seed := seedTrack(t, pool, album.ID, artist.ID, "Seed", 1, 100_000)

	w := callRadio(h, user, "seed_track="+uuidToString(seed.ID))
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d body=%s", w.Code, w.Body.String())
	}
	var resp RadioResponse
	_ = json.Unmarshal(w.Body.Bytes(), &resp)
	if len(resp.Tracks) != 1 {
		t.Fatalf("len = %d, want 1", len(resp.Tracks))
	}
	if resp.Tracks[0].Title != "Seed" {
		t.Errorf("seed not first: %v", resp.Tracks[0].Title)
	}
}

func TestHandleRadio_Typical_SeedFirstPlusPicks(t *testing.T) {
	h, pool := testHandlers(t)
	truncateLibrary(t, pool)
	user := seedUser(t, pool, "alice", "x", false)
	artist := seedArtist(t, pool, "X")
	album := seedAlbum(t, pool, artist.ID, "X", 1990)
	seed := seedTrack(t, pool, album.ID, artist.ID, "Seed", 1, 100_000)
	for i := 2; i <= 6; i++ {
		seedTrack(t, pool, album.ID, artist.ID, "T"+string(rune('0'+i)), i, 100_000)
	}

	w := callRadio(h, user, "seed_track="+uuidToString(seed.ID))
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d", w.Code)
	}
	var resp RadioResponse
	_ = json.Unmarshal(w.Body.Bytes(), &resp)
	if len(resp.Tracks) != 6 {
		t.Fatalf("len = %d, want 6 (seed + 5 picks)", len(resp.Tracks))
	}
	if resp.Tracks[0].Title != "Seed" {
		t.Errorf("seed not at index 0: %v", resp.Tracks[0].Title)
	}
}

func TestHandleRadio_UnknownSeedIs404(t *testing.T) {
	h, pool := testHandlers(t)
	user := seedUser(t, pool, "alice", "x", false)
	w := callRadio(h, user, "seed_track=00000000-0000-0000-0000-000000000000")
	if w.Code != http.StatusNotFound {
		t.Errorf("status = %d", w.Code)
	}
}

func TestHandleRadio_BadSeedIs400(t *testing.T) {
	h, pool := testHandlers(t)
	user := seedUser(t, pool, "alice", "x", false)
	w := callRadio(h, user, "seed_track=not-a-uuid")
	if w.Code != http.StatusBadRequest {
		t.Errorf("status = %d", w.Code)
	}
}

func TestHandleRadio_MissingSeedIs400(t *testing.T) {
	h, pool := testHandlers(t)
	user := seedUser(t, pool, "alice", "x", false)
	w := callRadio(h, user, "")
	if w.Code != http.StatusBadRequest {
		t.Errorf("status = %d", w.Code)
	}
}

func TestHandleRadio_BadLimitIs400(t *testing.T) {
	h, pool := testHandlers(t)
	truncateLibrary(t, pool)
	user := seedUser(t, pool, "alice", "x", false)
	artist := seedArtist(t, pool, "X")
	album := seedAlbum(t, pool, artist.ID, "X", 1990)
	seed := seedTrack(t, pool, album.ID, artist.ID, "Seed", 1, 100_000)
	w := callRadio(h, user, "seed_track="+uuidToString(seed.ID)+"&limit=0")
	if w.Code != http.StatusBadRequest {
		t.Errorf("limit=0 status = %d", w.Code)
	}
	w = callRadio(h, user, "seed_track="+uuidToString(seed.ID)+"&limit=-1")
	if w.Code != http.StatusBadRequest {
		t.Errorf("limit=-1 status = %d", w.Code)
	}
}

func TestHandleRadio_LimitClampedToMax(t *testing.T) {
	h, pool := testHandlers(t)
	truncateLibrary(t, pool)
	user := seedUser(t, pool, "alice", "x", false)
	artist := seedArtist(t, pool, "X")
	album := seedAlbum(t, pool, artist.ID, "X", 1990)
	seed := seedTrack(t, pool, album.ID, artist.ID, "Seed", 1, 100_000)
	for i := 2; i <= 6; i++ {
		seedTrack(t, pool, album.ID, artist.ID, "T"+string(rune('0'+i)), i, 100_000)
	}
	w := callRadio(h, user, "seed_track="+uuidToString(seed.ID)+"&limit=99999")
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d", w.Code)
	}
	var resp RadioResponse
	_ = json.Unmarshal(w.Body.Bytes(), &resp)
	// We only have 6 tracks; clamped limit (max 200) returns all 6.
	if len(resp.Tracks) != 6 {
		t.Errorf("len = %d, want 6", len(resp.Tracks))
	}
}