package filecatalog

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"reflect"
	"testing"
	"testing/fstest"
)

func TestFindYAMLFilesNestedSortedAndFiltered(t *testing.T) {
	root := t.TempDir()
	mustWriteFile(t, filepath.Join(root, "z", "prompt.yml"), "id: z")
	mustWriteFile(t, filepath.Join(root, "a", "profile.yaml"), "id: a")
	mustWriteFile(t, filepath.Join(root, "a", "ignore.txt"), "not yaml")
	mustWriteFile(t, filepath.Join(root, "b", "ignore.yaml.bak"), "not yaml")

	got, err := FindYAMLFiles(context.Background(), root)
	if err != nil {
		t.Fatalf("expected no error, got %v", err)
	}

	want := []string{
		filepath.Join(root, "a", "profile.yaml"),
		filepath.Join(root, "z", "prompt.yml"),
	}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("expected sorted YAML files %v, got %v", want, got)
	}
}

func TestFindYAMLFilesHonorsContextCancellation(t *testing.T) {
	root := t.TempDir()
	mustWriteFile(t, filepath.Join(root, "one.yaml"), "id: one")

	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	_, err := FindYAMLFiles(ctx, root)
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("expected context.Canceled, got %v", err)
	}
}

func TestFindFSYAMLFilesNestedSortedAndFiltered(t *testing.T) {
	fsys := fstest.MapFS{
		"prompts/z/prompt.yml":      &fstest.MapFile{Data: []byte("id: z")},
		"prompts/a/profile.yaml":    &fstest.MapFile{Data: []byte("id: a")},
		"prompts/a/ignore.txt":      &fstest.MapFile{Data: []byte("not yaml")},
		"prompts/b/ignore.yaml.bak": &fstest.MapFile{Data: []byte("not yaml")},
		"other/ignored.yaml":        &fstest.MapFile{Data: []byte("id: ignored")},
	}

	got, err := FindFSYAMLFiles(context.Background(), fsys, " prompts ")
	if err != nil {
		t.Fatalf("expected no error, got %v", err)
	}

	want := []string{
		"prompts/a/profile.yaml",
		"prompts/z/prompt.yml",
	}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("expected sorted YAML files %v, got %v", want, got)
	}
}

func TestFindFSYAMLFilesHonorsContextCancellation(t *testing.T) {
	fsys := fstest.MapFS{
		"one.yaml": &fstest.MapFile{Data: []byte("id: one")},
	}
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	_, err := FindFSYAMLFiles(ctx, fsys, ".")
	if !errors.Is(err, context.Canceled) {
		t.Fatalf("expected context.Canceled, got %v", err)
	}
}

func TestRelativePathNested(t *testing.T) {
	root := t.TempDir()
	path := filepath.Join(root, "nested", "profiles", "local.yaml")
	got := RelativePath(root, path)
	want := filepath.Join("nested", "profiles", "local.yaml")
	if got != want {
		t.Fatalf("expected relative path %q, got %q", want, got)
	}
}

func TestCleanFSRoot(t *testing.T) {
	tests := []struct {
		name string
		root string
		want string
	}{
		{name: "empty", root: "", want: "."},
		{name: "dot", root: ".", want: "."},
		{name: "trimmed", root: " prompts/../profiles ", want: "profiles"},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			if got := CleanFSRoot(tc.root); got != tc.want {
				t.Fatalf("expected %q, got %q", tc.want, got)
			}
		})
	}
}

func TestDisplayPath(t *testing.T) {
	tests := []struct {
		name string
		root string
		path string
		want string
	}{
		{name: "root dot", root: ".", path: "profiles/local.yaml", want: "profiles/local.yaml"},
		{name: "nested root", root: "profiles", path: "profiles/local.yaml", want: "local.yaml"},
		{name: "outside root", root: "profiles", path: "other/local.yaml", want: "other/local.yaml"},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			if got := DisplayPath(tc.root, tc.path); got != tc.want {
				t.Fatalf("expected %q, got %q", tc.want, got)
			}
		})
	}
}

func TestStemStripsYAMLExtensions(t *testing.T) {
	tests := []struct {
		name string
		in   string
		want string
	}{
		{name: "yaml", in: "prompt.yaml", want: "prompt"},
		{name: "yml", in: "profile.yml", want: "profile"},
		{name: "other", in: "file.txt", want: "file.txt"},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			if got := Stem(tc.in); got != tc.want {
				t.Fatalf("expected %q, got %q", tc.want, got)
			}
		})
	}
}

func TestIsYAMLFile(t *testing.T) {
	tests := []struct {
		name string
		in   string
		want bool
	}{
		{name: "yaml", in: "prompt.yaml", want: true},
		{name: "yml", in: "profile.yml", want: true},
		{name: "backup", in: "profile.yaml.bak", want: false},
		{name: "uppercase", in: "profile.YAML", want: false},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			if got := IsYAMLFile(tc.in); got != tc.want {
				t.Fatalf("expected %v, got %v", tc.want, got)
			}
		})
	}
}

func mustWriteFile(t *testing.T, path string, content string) {
	t.Helper()
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatalf("failed to create directory: %v", err)
	}
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatalf("failed to write file %q: %v", path, err)
	}
}