package art

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"image"
	"image/color"
	"image/png"
	"net"
	"net/http"
	"net/http/httptest"
	"os"
	"os/exec"
	"strings"
	"testing"
)

var ctx = context.Background()

func pngBytes(w, h int) []byte {
	img := image.NewRGBA(image.Rect(0, 0, w, h))
	for x := 0; x < w; x++ {
		img.Set(x, 0, color.RGBA{200, 0, 0, 255})
	}
	var b bytes.Buffer
	png.Encode(&b, img)
	return b.Bytes()
}

// fakeSources serves canned answers for every source.
func fakeSources(t *testing.T, failDeezer bool) *Client {
	t.Helper()
	mux := http.NewServeMux()
	var base string
	mux.HandleFunc("/search", func(w http.ResponseWriter, r *http.Request) { // iTunes
		fmt.Fprintf(w, `{"results":[{"artistName":"Avenged Sevenfold","collectionName":"Nightmare","artworkUrl100":"%s/img/100x100bb.jpg"}]}`, base)
	})
	mux.HandleFunc("/search/album", func(w http.ResponseWriter, r *http.Request) { // Deezer
		if failDeezer {
			http.Error(w, "down", 500)
			return
		}
		fmt.Fprintf(w, `{"data":[{"title":"Nightmare","cover_xl":"%s/dz/xl.jpg","cover_medium":"%s/dz/m.jpg","artist":{"name":"Avenged Sevenfold"}}]}`, base, base)
	})
	mux.HandleFunc("/ws/2/release-group/", func(w http.ResponseWriter, r *http.Request) { // MusicBrainz
		fmt.Fprint(w, `{"release-groups":[{"id":"sq","title":"Nightmare","artist-credit":[{"name":"Avenged Sevenfold"}]},
			{"id":"wide","title":"Nightmare (Live)","artist-credit":[{"name":"Avenged Sevenfold"}]},{"id":"none","title":"X"}]}`)
	})
	mux.HandleFunc("/release-group/sq/front-250", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "image/png")
		w.Write(pngBytes(250, 250))
	})
	mux.HandleFunc("/release-group/wide/front-250", func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "image/png")
		w.Write(pngBytes(250, 180))
	})
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { // DDG page with token
		if r.URL.Path == "/" {
			fmt.Fprint(w, `<html><script>vqd="4-12345";</script></html>`)
			return
		}
		http.NotFound(w, r)
	})
	mux.HandleFunc("/i.js", func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Query().Get("vqd") != "4-12345" || !strings.Contains(r.URL.Query().Get("f"), "layout:Square") {
			http.Error(w, "bad", 400)
			return
		}
		fmt.Fprint(w, `{"results":[{"title":"near square","image":"https://x/a.jpg","thumbnail":"t","width":600,"height":594},
			{"title":"square","image":"https://x/b.jpg","thumbnail":"t","width":800,"height":800},
			{"title":"tiny","image":"https://x/c.jpg","thumbnail":"t","width":200,"height":200}]}`)
	})
	srv := httptest.NewServer(mux)
	t.Cleanup(srv.Close)
	base = srv.URL
	c := New("test")
	c.HTTP = srv.Client() // the safe client refuses loopback, which the fakes use
	c.ITunesURL, c.DeezerURL, c.MusicBrainzURL, c.CAAURL, c.DDGURL, c.GoogleURL = base, base, base, base, base, base
	return c
}

func TestSearchSquareOnly(t *testing.T) {
	c := fakeSources(t, false)
	res, errs := c.Search(ctx, Query{Artist: "Avenged Sevenfold", Album: "Nightmare"}, Config{Sources: AllSources})
	if len(errs) != 0 {
		t.Fatalf("errors: %v", errs)
	}
	got := map[string]Result{}
	for _, r := range res {
		got[r.Source+":"+r.Title] = r
	}
	for _, want := range []string{"itunes:Nightmare", "deezer:Nightmare", "musicbrainz:Nightmare", "duckduckgo:square"} {
		if _, ok := got[want]; !ok {
			t.Errorf("missing %s in %+v", want, res)
		}
	}
	for _, not := range []string{"duckduckgo:near square", "duckduckgo:tiny", "musicbrainz:Nightmare (Live)"} {
		if _, ok := got[not]; ok {
			t.Errorf("%s must be filtered out (not square or too small)", not)
		}
	}
	if r := got["itunes:Nightmare"]; !strings.HasSuffix(r.URL, "/img/1000x1000bb.jpg") || res[0].Source != ITunes {
		t.Errorf("iTunes should come first at 1000px: %+v", r)
	}
	for _, r := range res {
		if r.Source == Google {
			t.Error("Google must not be queried without an API key")
		}
	}
}

func TestOneFailingSourceDoesNotHideOthers(t *testing.T) {
	c := fakeSources(t, true)
	res, errs := c.Search(ctx, Query{Artist: "A", Album: "B"}, Config{Sources: []string{ITunes, Deezer}})
	if errs[Deezer] == "" || len(res) != 1 || res[0].Source != ITunes {
		t.Fatalf("want iTunes result plus a Deezer error, got %+v %v", res, errs)
	}
}

func TestSquare(t *testing.T) {
	for _, c := range []struct {
		w, h int
		want bool
	}{{1000, 1000, true}, {1000, 996, true}, {600, 594, false}, {500, 498, true}, {0, 0, false}, {1200, 1100, false}} {
		if Square(c.w, c.h) != c.want {
			t.Errorf("Square(%d,%d) != %v", c.w, c.h, c.want)
		}
	}
}

func TestSafeFetch(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path == "/page" {
			w.Header().Set("Content-Type", "text/html")
			fmt.Fprint(w, "<html>")
			return
		}
		w.Header().Set("Content-Type", "image/png")
		w.Write(pngBytes(10, 10))
	}))
	defer srv.Close()
	c := New("test") // the real, safe client
	if _, err := c.FetchImage(ctx, srv.URL+"/img.png"); !errors.Is(err, ErrBlockedAddress) {
		t.Fatalf("loopback must be refused, got %v", err)
	}
	for _, u := range []string{"file:///etc/passwd", "ftp://x/y.png", "gopher://x", "not a url"} {
		if _, err := c.FetchImage(ctx, u); err == nil {
			t.Errorf("%q must be refused", u)
		}
	}
	c.HTTP = srv.Client()
	if _, err := c.FetchImage(ctx, srv.URL+"/page"); err == nil || !strings.Contains(err.Error(), "not an image") {
		t.Fatalf("non-images must be refused, got %v", err)
	}
	if b, err := c.FetchImage(ctx, srv.URL+"/img.png"); err != nil || len(b) == 0 {
		t.Fatalf("image fetch: %v", err)
	}
	for _, ip := range []string{"10.0.0.1", "192.168.1.1", "172.16.0.1", "169.254.169.254", "100.64.0.1", "::1", "fc00::1", "0.0.0.0"} {
		if !blockedIP(parseIP(ip)) {
			t.Errorf("%s should be blocked", ip)
		}
	}
	if blockedIP(parseIP("1.1.1.1")) {
		t.Error("public addresses are allowed")
	}
}

func TestPrepare(t *testing.T) {
	ff, err := exec.LookPath("ffmpeg")
	if err != nil {
		t.Skip("ffmpeg not installed")
	}
	s := &Store{Dir: t.TempDir(), FFmpeg: ff}
	p, err := s.Prepare(ctx, pngBytes(1600, 1600), 1000)
	if err != nil {
		t.Fatal(err)
	}
	if p.Width != 1000 || p.Height != 1000 || !p.Square {
		t.Fatalf("want 1000x1000 square, got %+v", p)
	}
	path, err := s.Path(p.Token)
	if err != nil {
		t.Fatal(err)
	}
	b, _ := os.ReadFile(path)
	if len(b) < 3 || b[0] != 0xFF || b[1] != 0xD8 {
		t.Fatal("prepared image should be a JPEG")
	}
	if small, _ := s.Prepare(ctx, pngBytes(300, 300), 1000); small.Width != 300 {
		t.Fatal("images are never enlarged")
	}
	if _, err := s.Prepare(ctx, []byte("not an image"), 1000); err == nil {
		t.Fatal("garbage must be refused")
	}
	for _, bad := range []string{"../etc", "abc", strings.Repeat("g", 32)} {
		if _, err := s.Path(bad); !errors.Is(err, ErrBadToken) {
			t.Errorf("token %q must be refused", bad)
		}
	}
}

func parseIP(s string) net.IP { return net.ParseIP(s) }