package gitea

import (
	"context"
	"crypto/ed25519"
	"crypto/rand"
	"crypto/sha512"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"

	"github.com/wailsapp/wails/v3/pkg/updater"
)

func TestCompareSemver(t *testing.T) {
	cases := []struct {
		a, b string
		want int
	}{
		{"1.99.0", "1.6.8", 1},
		{"1.6.8", "1.99.0", -1},
		{"1.99.0", "1.99.0", 0},
		{"v1.99.0", "1.99.0", 0},
		{"2.0.0", "1.99.9", 1},
		{"1.99.0-rc1", "1.99.0", -1},
		{"1.99.0", "1.99.0-rc1", 1},
		{"1.99.0-rc1", "1.99.0-rc2", -1},
		{"1.10.0", "1.9.0", 1}, // numeric, not lexicographic
		{"garbage", "1.0.0", -1},
		{"1.0.0", "garbage", 1},
		{"", "", 0},
	}
	for _, c := range cases {
		if got := compareSemver(c.a, c.b); got != c.want {
			t.Errorf("compareSemver(%q, %q) = %d, want %d", c.a, c.b, got, c.want)
		}
	}
}

const testAsset = "AniTrack-linux-amd64"
const testData = "artifact-bytes"

type releaseSpec struct {
	tag         string
	draft       bool
	prerelease  bool
	withAsset   bool
	withSidecar bool
}

// buildServer serves a canned releases index. Every spec with withAsset gets
// the test artifact; sidecars (.sha512/.sig, correctly formed) are served
// only if at least one spec sets withSidecar.
func buildServer(t *testing.T, specs []releaseSpec) *httptest.Server {
	t.Helper()
	_, priv, err := ed25519.GenerateKey(rand.Reader)
	if err != nil {
		t.Fatal(err)
	}
	data := []byte(testData)
	sum := sha512.Sum512(data)
	sha := hex.EncodeToString(sum[:]) + "  " + testAsset + "\n"
	sig := base64.StdEncoding.EncodeToString(ed25519.Sign(priv, sum[:])) + "\n"
	serveSidecars := false
	for _, s := range specs {
		if s.withSidecar {
			serveSidecars = true
		}
	}
	var srv *httptest.Server
	srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch {
		case strings.HasSuffix(r.URL.Path, "/releases"):
			w.Header().Set("Content-Type", "application/json")
			var b strings.Builder
			b.WriteString("[")
			for i, s := range specs {
				assets := ""
				if s.withAsset {
					assets = fmt.Sprintf(`{"name":%q,"size":%d,"browser_download_url":%q}`,
						testAsset, len(data), srv.URL+"/dl/"+testAsset)
				}
				if i > 0 {
					b.WriteString(",")
				}
				fmt.Fprintf(&b, `{"tag_name":%q,"name":%q,"body":"notes","draft":%v,"prerelease":%v,"published_at":"2026-09-16T00:00:00Z","assets":[%s]}`,
					s.tag, s.tag, s.draft, s.prerelease, assets)
			}
			b.WriteString("]")
			fmt.Fprint(w, b.String())
		case serveSidecars && r.URL.Path == "/dl/"+testAsset+".sha512":
			fmt.Fprint(w, sha)
		case serveSidecars && r.URL.Path == "/dl/"+testAsset+".sig":
			fmt.Fprint(w, sig)
		case serveSidecars && r.URL.Path == "/dl/"+testAsset:
			w.Write(data)
		default:
			http.NotFound(w, r)
		}
	}))
	return srv
}

func testProvider(srv *httptest.Server, allowPre bool) *Provider {
	p, err := New(Config{
		BaseURL:         srv.URL,
		Owner:           "o",
		Repo:            "r",
		AssetName:       testAsset,
		AllowPrerelease: allowPre,
	})
	if err != nil {
		panic(err)
	}
	return p
}

func TestCheckFindsNewest(t *testing.T) {
	srv := buildServer(t, []releaseSpec{
		{tag: "1.6.8", withAsset: true, withSidecar: true},
		{tag: "1.99.0", withAsset: true, withSidecar: true},
	})
	defer srv.Close()
	rel, err := testProvider(srv, false).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.6.8"})
	if err != nil {
		t.Fatal(err)
	}
	if rel == nil {
		t.Fatal("expected a release, got up-to-date")
	}
	if rel.Version != "1.99.0" {
		t.Errorf("version = %q, want 1.99.0", rel.Version)
	}
	if rel.Verification == nil || rel.Verification.DigestAlgo != "sha512" || rel.Verification.SignatureAlgo != "ed25519ph" {
		t.Errorf("verification not populated: %+v", rel.Verification)
	}
	if len(rel.Verification.Digest) != 64 || len(rel.Verification.Signature) == 0 {
		t.Errorf("verification malformed: %+v", rel.Verification)
	}
	if rel.Notes != "notes" {
		t.Errorf("notes = %q", rel.Notes)
	}
}

func TestCheckUpToDate(t *testing.T) {
	srv := buildServer(t, []releaseSpec{{tag: "1.99.0", withAsset: true, withSidecar: true}})
	defer srv.Close()
	rel, err := testProvider(srv, false).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.99.0"})
	if err != nil {
		t.Fatal(err)
	}
	if rel != nil {
		t.Errorf("expected up-to-date, got %s", rel.Version)
	}
}

func TestCheckSkipsDraftPrereleaseAndMissingAsset(t *testing.T) {
	srv := buildServer(t, []releaseSpec{
		{tag: "1.99.2", draft: true, withAsset: true, withSidecar: true},
		{tag: "1.99.1", prerelease: true, withAsset: true, withSidecar: true},
		{tag: "1.99.0", withAsset: false},
		{tag: "1.6.9", withAsset: true, withSidecar: true},
	})
	defer srv.Close()
	rel, err := testProvider(srv, false).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.6.8"})
	if err != nil {
		t.Fatal(err)
	}
	if rel == nil || rel.Version != "1.6.9" {
		t.Fatalf("version = %v, want 1.6.9 (draft/prerelease/asset-less skipped)", rel)
	}
}

func TestCheckAllowPrerelease(t *testing.T) {
	srv := buildServer(t, []releaseSpec{
		{tag: "1.99.1-rc1", prerelease: true, withAsset: true, withSidecar: true},
	})
	defer srv.Close()
	rel, err := testProvider(srv, true).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.99.0"})
	if err != nil {
		t.Fatal(err)
	}
	if rel == nil || rel.Version != "1.99.1-rc1" {
		t.Fatalf("version = %v, want 1.99.1-rc1", rel)
	}
	if rel.Channel != "beta" {
		t.Errorf("channel = %q, want beta", rel.Channel)
	}
}

func TestCheckFailsClosedWithoutSidecars(t *testing.T) {
	srv := buildServer(t, []releaseSpec{{tag: "1.99.0", withAsset: true, withSidecar: false}})
	defer srv.Close()
	_, err := testProvider(srv, false).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.6.8"})
	if err == nil {
		t.Fatal("expected error for missing sidecars, got nil")
	}
}

func TestCheckServerError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "boom", http.StatusInternalServerError)
	}))
	defer srv.Close()
	_, err := testProvider(srv, false).Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.6.8"})
	if err == nil {
		t.Fatal("expected error for 500, got nil")
	}
}

func TestDownloadStreamsWithProgress(t *testing.T) {
	srv := buildServer(t, []releaseSpec{{tag: "1.99.0", withAsset: true, withSidecar: true}})
	defer srv.Close()
	p := testProvider(srv, false)
	rel, err := p.Check(context.Background(), updater.CheckRequest{CurrentVersion: "1.6.8"})
	if err != nil || rel == nil {
		t.Fatalf("check: %v %v", rel, err)
	}
	f, err := os.CreateTemp("", "dl")
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(f.Name())
	var calls int
	var last int64
	err = p.Download(context.Background(), rel, f, func(written, total int64) {
		calls++
		last = written
		if total != int64(len(testData)) {
			t.Errorf("total = %d", total)
		}
	})
	f.Close()
	if err != nil {
		t.Fatal(err)
	}
	if calls == 0 || last != int64(len(testData)) {
		t.Errorf("progress calls=%d last=%d", calls, last)
	}
	got, _ := os.ReadFile(f.Name())
	if string(got) != testData {
		t.Errorf("body = %q", got)
	}
}

func TestNewValidatesConfig(t *testing.T) {
	if _, err := New(Config{}); err == nil {
		t.Error("expected error for empty config")
	}
}

// TestLiveGiteaCheck hits the real instance. Opt-in only:
// ANITRACK_LIVE_TEST=1 go test ./updater/gitea/ -run TestLiveGiteaCheck -v
func TestLiveGiteaCheck(t *testing.T) {
	if os.Getenv("ANITRACK_LIVE_TEST") == "" {
		t.Skip("set ANITRACK_LIVE_TEST=1 to run")
	}
	p, err := New(Config{
		BaseURL:   "https://git.linuxhg.com",
		Owner:     "john-okeefe",
		Repo:      "Anitrack",
		AssetName: "AniTrack-linux-amd64",
	})
	if err != nil {
		t.Fatal(err)
	}
	rel, err := p.Check(context.Background(), updater.CheckRequest{CurrentVersion: "0.0.0"})
	if err != nil {
		t.Fatal(err)
	}
	if rel == nil {
		// Correct until CI publishes the bare-binary asset: no release
		// carries AniTrack-linux-amd64 yet, so there is nothing to offer.
		// This still proves API reachability + response parsing live.
		t.Log("no matching asset published yet (expected until CI ships AniTrack-linux-amd64)")
		return
	}
	t.Logf("latest=%s notes=%d bytes", rel.Version, len(rel.Notes))
	var n int64
	err = p.Download(context.Background(), rel, io.Discard, func(w, _ int64) { n = w })
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("downloaded %d bytes", n)
}