package runner

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

func writeTempFile(t *testing.T, dir, name, content string) string {
	t.Helper()
	path := filepath.Join(dir, name)
	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestRgListFiles(t *testing.T) {
	dir := t.TempDir()
	writeTempFile(t, dir, "a.txt", "foo bar\nbaz\n")
	writeTempFile(t, dir, "b.txt", "no match here\n")
	writeTempFile(t, dir, "c.txt", "another foo\n")

	files, err := RgListFiles("foo", dir)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(files) != 2 {
		t.Fatalf("want 2 files, got %d: %v", len(files), files)
	}
	sort.Strings(files)
	if filepath.Base(files[0]) != "a.txt" || filepath.Base(files[1]) != "c.txt" {
		t.Errorf("unexpected files: %v", files)
	}
}

func TestRgListFiles_NoMatches(t *testing.T) {
	dir := t.TempDir()
	writeTempFile(t, dir, "a.txt", "hello world\n")

	files, err := RgListFiles("xyz_no_match", dir)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if files != nil {
		t.Errorf("want nil, got %v", files)
	}
}

func TestRgListFiles_CaseInsensitive(t *testing.T) {
	dir := t.TempDir()
	writeTempFile(t, dir, "a.txt", "FOO bar\n")
	writeTempFile(t, dir, "b.txt", "no match\n")

	files, err := RgListFiles("foo", dir, "-i")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(files) != 1 || filepath.Base(files[0]) != "a.txt" {
		t.Errorf("want [a.txt], got %v", files)
	}
}

func TestSplitLines(t *testing.T) {
	tests := []struct {
		input string
		want  []string
	}{
		{"", nil},
		{"a\n", []string{"a"}},
		{"a\nb\n", []string{"a", "b"}},
		{"a\nb\nc", []string{"a", "b", "c"}},
		{"\n\n", nil}, // only trailing newlines — trimmed to empty, returns nil
	}
	for _, tt := range tests {
		got := splitLines(tt.input)
		if len(got) != len(tt.want) {
			t.Errorf("splitLines(%q) = %v, want %v", tt.input, got, tt.want)
			continue
		}
		for i := range got {
			if got[i] != tt.want[i] {
				t.Errorf("splitLines(%q)[%d] = %q, want %q", tt.input, i, got[i], tt.want[i])
			}
		}
	}
}