package webhook

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"git.folja.dev/awayatan/yaju-is-always-watching-you/internal/forgejo"
)

type fakeDispatcher struct {
	comments int
	pushes   int
}

func (f *fakeDispatcher) HandleIssueComment(forgejo.IssueCommentPayload) error {
	f.comments++
	return nil
}

func (f *fakeDispatcher) HandlePush(forgejo.PushPayload) error {
	f.pushes++
	return nil
}

func sign(secret, body string) string {
	mac := hmac.New(sha256.New, []byte(secret))
	mac.Write([]byte(body))
	return hex.EncodeToString(mac.Sum(nil))
}

func TestServeHTTP_RejectsBadSignature(t *testing.T) {
	fd := &fakeDispatcher{}
	h := NewHandler("secret", fd)

	body := `{}`
	req := httptest.NewRequest(http.MethodPost, "/webhook", strings.NewReader(body))
	req.Header.Set("X-Forgejo-Event", "push")
	req.Header.Set("X-Forgejo-Signature", "deadbeef")
	rec := httptest.NewRecorder()

	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusUnauthorized)
	}
	if fd.pushes != 0 {
		t.Fatalf("dispatcher should not run on bad signature, pushes = %d", fd.pushes)
	}
}

func TestServeHTTP_DispatchesPush(t *testing.T) {
	fd := &fakeDispatcher{}
	h := NewHandler("secret", fd)

	body := `{"ref":"refs/heads/main"}`
	req := httptest.NewRequest(http.MethodPost, "/webhook", strings.NewReader(body))
	req.Header.Set("X-Forgejo-Event", "push")
	req.Header.Set("X-Forgejo-Signature", sign("secret", body))
	rec := httptest.NewRecorder()

	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusNoContent {
		t.Fatalf("status = %d, want %d, body=%s", rec.Code, http.StatusNoContent, rec.Body.String())
	}
	if fd.pushes != 1 {
		t.Fatalf("pushes = %d, want 1", fd.pushes)
	}
}

func TestServeHTTP_DispatchesIssueComment(t *testing.T) {
	fd := &fakeDispatcher{}
	h := NewHandler("secret", fd)

	body := `{"action":"created"}`
	req := httptest.NewRequest(http.MethodPost, "/webhook", strings.NewReader(body))
	req.Header.Set("X-Forgejo-Event", "issue_comment")
	req.Header.Set("X-Forgejo-Signature", sign("secret", body))
	rec := httptest.NewRecorder()

	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusNoContent {
		t.Fatalf("status = %d, want %d, body=%s", rec.Code, http.StatusNoContent, rec.Body.String())
	}
	if fd.comments != 1 {
		t.Fatalf("comments = %d, want 1", fd.comments)
	}
}

func TestServeHTTP_IgnoresUnhandledEvent(t *testing.T) {
	fd := &fakeDispatcher{}
	h := NewHandler("secret", fd)

	body := `{}`
	req := httptest.NewRequest(http.MethodPost, "/webhook", strings.NewReader(body))
	req.Header.Set("X-Forgejo-Event", "fork")
	req.Header.Set("X-Forgejo-Signature", sign("secret", body))
	rec := httptest.NewRecorder()

	h.ServeHTTP(rec, req)

	if rec.Code != http.StatusNoContent {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNoContent)
	}
	if fd.comments != 0 || fd.pushes != 0 {
		t.Fatalf("dispatcher should not be called for unhandled events")
	}
}