package item

import (
	"bytes"
	"log"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// Regression: an item file whose declared id: disagrees with its filename was
// silently loaded under the filename with no diagnostic. ItemStore must warn,
// because the author has no other sign that the id they wrote is ignored.

func captureLog(t *testing.T, fn func()) string {
	t.Helper()
	var buf bytes.Buffer
	old := log.Writer()
	log.SetOutput(&buf)
	defer log.SetOutput(old)
	fn()
	return buf.String()
}

func writeItemFile(t *testing.T, dir, name, body string) {
	t.Helper()
	path := filepath.Join(dir, "items", name)
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
}

func TestItemStoreWarnsOnDeclaredIDMismatch(t *testing.T) {
	dir := t.TempDir()
	writeItemFile(t, dir, "foo.yaml", "id: bar\nname: Foo\n")
	s := NewItemStore(dir)

	out := captureLog(t, func() {
		def, err := s.Load("foo")
		if err != nil {
			t.Fatalf("load: %v", err)
		}
		if def.ID != "foo" {
			t.Fatalf("filename must win: ID = %q, want foo", def.ID)
		}
	})
	if !strings.Contains(out, "declares id") {
		t.Fatalf("expected an id-mismatch warning, got log %q", out)
	}
}

func TestItemStoreDoesNotWarnWhenIDMatchesOrAbsent(t *testing.T) {
	dir := t.TempDir()
	writeItemFile(t, dir, "foo.yaml", "id: foo\nname: Foo\n")
	writeItemFile(t, dir, "baz.yaml", "name: Baz\n")
	s := NewItemStore(dir)

	out := captureLog(t, func() {
		if _, err := s.Load("foo"); err != nil {
			t.Fatal(err)
		}
		if _, err := s.Load("baz"); err != nil {
			t.Fatal(err)
		}
	})
	if strings.Contains(out, "declares id") {
		t.Fatalf("unexpected id-mismatch warning: %q", out)
	}
}

func TestItemStoreLoadAllWarnsOnDeclaredIDMismatch(t *testing.T) {
	dir := t.TempDir()
	writeItemFile(t, dir, "foo.yaml", "id: bar\nname: Foo\n")
	s := NewItemStore(dir)

	out := captureLog(t, func() {
		if _, err := s.LoadAll(); err != nil {
			t.Fatal(err)
		}
	})
	if !strings.Contains(out, "declares id") {
		t.Fatalf("expected an id-mismatch warning from LoadAll, got %q", out)
	}
}