package api_test

import (
	"bytes"
	"image"
	"image/color"
	"image/jpeg"
	"image/png"
	"io"
	"net/http"
	"testing"
)

func testImage(w, h int) *image.RGBA {
	img := image.NewRGBA(image.Rect(0, 0, w, h))
	for y := 0; y < h; y++ {
		for x := 0; x < w; x++ {
			img.Set(x, y, color.RGBA{R: uint8(x), G: uint8(y), B: 200, A: 255})
		}
	}
	return img
}

func pngBytes(t *testing.T, img image.Image) []byte {
	t.Helper()
	var b bytes.Buffer
	if err := png.Encode(&b, img); err != nil {
		t.Fatal(err)
	}
	return b.Bytes()
}

// putRaw sends a non-JSON body with the administrator's key.
func (s *ts) putRaw(t *testing.T, path string, body []byte) *http.Response {
	t.Helper()
	req, _ := http.NewRequest(http.MethodPut, s.URL+path, bytes.NewReader(body))
	req.Header.Set("Authorization", "Bearer "+s.key)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	return resp
}

func TestAvatar_UploadNormalizesAndServes(t *testing.T) {
	s := newTS(t)
	uid, call := member(t, s, "ava")
	path := "/api/users/" + id64(uid) + "/avatar"

	if resp := call(http.MethodGet, path, nil); resp.StatusCode != http.StatusNotFound {
		t.Fatalf("GET before upload: %d, want 404", resp.StatusCode)
	}

	// A non-square JPEG, bigger than the stored size: cropped and scaled to 256².
	var jb bytes.Buffer
	if err := jpeg.Encode(&jb, testImage(600, 400), nil); err != nil {
		t.Fatal(err)
	}
	resp := s.putRaw(t, path, jb.Bytes()) // an administrator may set anybody's
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("PUT: %d", resp.StatusCode)
	}
	var out struct {
		Version int64 `json:"avatar_version"`
	}
	decode(t, resp, &out)

	resp = call(http.MethodGet, path, nil)
	if resp.StatusCode != http.StatusOK || resp.Header.Get("Content-Type") != "image/png" {
		t.Fatalf("GET: %d %q", resp.StatusCode, resp.Header.Get("Content-Type"))
	}
	body, _ := io.ReadAll(resp.Body)
	resp.Body.Close()
	img, err := png.Decode(bytes.NewReader(body))
	if err != nil {
		t.Fatalf("served bytes are not a PNG: %v", err)
	}
	if b := img.Bounds(); b.Dx() != 256 || b.Dy() != 256 {
		t.Errorf("stored size %v, want 256x256", b)
	}

	var users []struct {
		ID            int64  `json:"id"`
		AvatarVersion *int64 `json:"avatar_version"`
	}
	decode(t, call(http.MethodGet, "/api/users", nil), &users)
	found := false
	for _, u := range users {
		if u.ID == uid {
			found = true
			if u.AvatarVersion == nil || *u.AvatarVersion != out.Version {
				t.Errorf("user list avatar_version = %v, want %d", u.AvatarVersion, out.Version)
			}
		}
	}
	if !found {
		t.Fatal("user not listed")
	}

	if resp := call(http.MethodDelete, path, nil); resp.StatusCode != http.StatusNoContent {
		t.Fatalf("DELETE: %d", resp.StatusCode)
	}
	if resp := call(http.MethodGet, path, nil); resp.StatusCode != http.StatusNotFound {
		t.Fatalf("GET after delete: %d, want 404", resp.StatusCode)
	}
}

func TestAvatar_Rejections(t *testing.T) {
	s := newTS(t)
	_, other := member(t, s, "other")
	uid, _ := member(t, s, "ava2")
	path := "/api/users/" + id64(uid) + "/avatar"

	if resp := other(http.MethodPut, path, nil); resp.StatusCode != http.StatusForbidden {
		t.Errorf("another member PUT: %d, want 403", resp.StatusCode)
	}
	if resp := other(http.MethodDelete, path, nil); resp.StatusCode != http.StatusForbidden {
		t.Errorf("another member DELETE: %d, want 403", resp.StatusCode)
	}
	if resp := s.putRaw(t, path, []byte("not an image")); resp.StatusCode != http.StatusBadRequest {
		t.Errorf("garbage: %d, want 400", resp.StatusCode)
	}
	if resp := s.putRaw(t, path, make([]byte, 2<<20)); resp.StatusCode != http.StatusRequestEntityTooLarge {
		t.Errorf("oversize: %d, want 413", resp.StatusCode)
	}
	if resp := s.putRaw(t, "/api/users/999999/avatar", pngBytes(t, testImage(32, 32))); resp.StatusCode != http.StatusNotFound {
		t.Errorf("unknown user: %d, want 404", resp.StatusCode)
	}

	req, _ := http.NewRequest(http.MethodGet, s.URL+path, nil)
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	if resp.StatusCode != http.StatusUnauthorized {
		t.Errorf("unauthenticated GET: %d, want 401", resp.StatusCode)
	}
}

func TestAvatar_RemovedWithTheUser(t *testing.T) {
	s := newTS(t)
	uid, _ := member(t, s, "gone")
	path := "/api/users/" + id64(uid) + "/avatar"
	if resp := s.putRaw(t, path, pngBytes(t, testImage(64, 64))); resp.StatusCode != http.StatusOK {
		t.Fatalf("PUT: %d", resp.StatusCode)
	}
	if resp := s.req(t, http.MethodDelete, "/api/users/"+id64(uid), nil); resp.StatusCode >= 300 {
		t.Fatalf("delete user: %d", resp.StatusCode)
	}
	var n int
	if err := s.db.QueryRow("SELECT COUNT(*) FROM user_avatars WHERE user_id = $1", uid).Scan(&n); err != nil || n != 0 {
		t.Errorf("avatar rows after user delete = %d (%v), want 0", n, err)
	}
}