package lint

import (
	"os"
	"path/filepath"
	"testing"
)

// writeFixture drops src at name under dir, creating parents.
func writeFixture(t *testing.T, dir, name, src string) string {
	t.Helper()
	path := filepath.Join(dir, name)
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(src), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestRuleRawErrorRender(t *testing.T) {
	dir := t.TempDir()

	leaky := writeFixture(t, dir, "handlers.go", `package server

func (h *H) bad(err error, attErr error) {
	h.renderFooPage(w, r, "", "Failed to save: "+err.Error())        // line 4: flag
	fireErrorToast(w, attErr.Error())                                // line 5: flag (suffixed identifier)
	http.Error(w, err.Error(), 500)                                  // line 6: flag
	h.Logger.Error("failed", slog.Any("error", err))                 // line 7: ok — slog only
	slog.Error("failed to save: " + err.Error())                     // line 8: ok — slog carve-out
	return fmt.Errorf("wrap: %w", err)                               // line 9: ok — no UI sink
	msg := err.Error()                                               // line 10: ok — no UI sink on this line
	h.renderFooPage(w, r, "", "Failed to save. See the logs.")       // line 11: ok — generic text only
	fireSuccessToast(w, "saved "+err.Error())                        // line 12: flag (success toast is a sink too)
}
`)

	writeFixture(t, dir, "handlers_test.go", `package server

func TestX(t *testing.T) {
	h.renderFooPage(w, r, "", "boom: "+err.Error()) // tests are exempt
}
`)

	got := ruleRawErrorRender(dir)

	wantLines := map[int]bool{4: true, 5: true, 6: true, 12: true}
	if len(got) != len(wantLines) {
		t.Fatalf("got %d violations, want %d: %+v", len(got), len(wantLines), got)
	}
	for _, viol := range got {
		if viol.File != leaky {
			t.Errorf("violation in %s, want only %s", viol.File, leaky)
		}
		if viol.Rule != "raw-error-render" {
			t.Errorf("rule = %q, want raw-error-render", viol.Rule)
		}
		if !wantLines[viol.Line] {
			t.Errorf("unexpected violation at line %d", viol.Line)
		}
		delete(wantLines, viol.Line)
	}
	for line := range wantLines {
		t.Errorf("missing violation at line %d", line)
	}
}

func TestRuleRawErrorRender_CleanDir(t *testing.T) {
	dir := t.TempDir()
	writeFixture(t, dir, "clean.go", `package server

func (h *H) good(err error) {
	if fe, ok := web.FieldErrorsFromDB(err, nil); ok {
		h.renderFooFormErrors(w, r, fe)
		return
	}
	h.Logger.Error("failed to save", slog.Any("error", err))
	h.renderFooPage(w, r, "", "Failed to save. Details are in the server logs.")
}
`)
	if got := ruleRawErrorRender(dir); len(got) != 0 {
		t.Fatalf("got %d violations on clean fixture, want 0: %+v", len(got), got)
	}
}