package genius

import (
	"context"
	"errors"
	"io"
	"net/http"
	"strings"
	"testing"

	"github.com/stretchr/testify/require"
)

type transportFunc func(*http.Request) (*http.Response, error)

func (f transportFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }

func TestLyricsFormatting(t *testing.T) {
	text, err := parseLyrics([]byte(`<header>Not lyrics</header><div data-lyrics-container="true"><div class="LyricsHeader-x">Title</div>[Куплет 1]<br>Привет &amp; <a href="/annotation">мир</a><br><br>Next <b>line</b><span data-exclude-from-selection="true">Embed</span><script>bad()</script></div><div data-lyrics-container="true">[Припев]<br>Again<button>Share</button></div>`))
	require.NoError(t, err)
	require.Equal(t, "[Куплет 1]\nПривет & мир\n\nNext line\n\n[Припев]\nAgain", text)
}

func TestUnavailable(t *testing.T) {
	for _, page := range []string{`<h1>Just a moment</h1>`, `<div data-lyrics-container="true"> </div>`, `<script>window.__PRELOADED_STATE__ = JSON.parse('broken')</script>`} {
		_, err := parseLyrics([]byte(page))
		require.ErrorIs(t, err, ErrLyricsUnavailable)
	}
}

func TestEmbeddedLyrics(t *testing.T) {
	text, err := parseLyrics([]byte(`<script>window.__PRELOADED_STATE__ = JSON.parse('{"songPage":{"lyricsData":{"body":{"html":"<p>[Verse]<br>It\'s \\"fine\\" &amp; good<br>Привет</p>"}}}}')</script>`))
	require.NoError(t, err)
	require.Equal(t, "[Verse]\nIt's \"fine\" & good\nПривет", text)
}

func TestURLValidation(t *testing.T) {
	c := New("secret")
	c.http.Transport = transportFunc(func(*http.Request) (*http.Response, error) { t.Fatal("unexpected network call"); return nil, nil })
	for _, u := range []string{"https://evil.test/song-lyrics", "http://genius.com/song-lyrics", "https://genius.com:443/song-lyrics", "https://secret@genius.com/song-lyrics", "https://genius.com/artists/test"} {
		_, err := c.FetchLyrics(context.Background(), u)
		require.Error(t, err)
	}
}

func TestRequests(t *testing.T) {
	c := New("secret")
	c.http.Transport = transportFunc(func(r *http.Request) (*http.Response, error) {
		body := `<div data-lyrics-container="true">Synthetic test text</div>`
		if r.URL.Host == "api.genius.com" {
			require.Equal(t, "Bearer secret", r.Header.Get("Authorization"))
			require.Equal(t, "artist & title", r.URL.Query().Get("q"))
			body = `{"response":{"hits":[{"type":"song","result":{"id":12,"title":"Example","url":"https://genius.com/example-lyrics","primary_artist":{"name":"Artist"}}}]}}`
		} else {
			require.Empty(t, r.Header.Get("Authorization"))
			require.Empty(t, r.URL.RawQuery)
		}
		return &http.Response{StatusCode: 200, Body: io.NopCloser(strings.NewReader(body)), Header: make(http.Header)}, nil
	})
	songs, err := c.Search(context.Background(), "artist & title")
	require.NoError(t, err)
	require.Len(t, songs, 1)
	lyrics, err := c.FetchLyrics(context.Background(), songs[0].URL+"?tracking=1")
	require.NoError(t, err)
	require.Equal(t, "Synthetic test text", lyrics.Text)
	require.Equal(t, songs[0].URL, lyrics.SourceURL)
	require.False(t, lyrics.FetchedAt.IsZero())
}

func TestHTTPFailures(t *testing.T) {
	for _, status := range []int{401, 403, 404, 429, 500} {
		c := New("secret")
		c.http.Transport = transportFunc(func(*http.Request) (*http.Response, error) {
			return &http.Response{StatusCode: status, Header: http.Header{"Retry-After": {"60"}}, Body: io.NopCloser(strings.NewReader("private upstream body"))}, nil
		})
		_, err := c.Search(context.Background(), "test")
		var httpErr *HTTPError
		require.True(t, errors.As(err, &httpErr))
		require.Equal(t, status, httpErr.StatusCode)
		require.Equal(t, "60", httpErr.RetryAfter)
		require.NotContains(t, err.Error(), "private")
	}
}

func TestRedirects(t *testing.T) {
	c := New("secret")
	first, _ := http.NewRequest("GET", "https://api.genius.com/search", nil)
	for _, endpoint := range []string{"http://api.genius.com/search", "https://genius.com/song-lyrics", "https://evil.test/"} {
		req, _ := http.NewRequest("GET", endpoint, nil)
		require.Error(t, c.http.CheckRedirect(req, []*http.Request{first}))
	}
}