package commandkit

import (
	"bytes"
	"go.yaml.in/yaml/v4"
	"io"
	"reflect"
	"strings"
	"testing"
)

func TestEffectiveYAMLFramingPreservesOneNativeDocument(t *testing.T) {
	for _, native := range []string{
		"--- {setting: value}\n", "---\t{setting: value}\n", "--- value\n",
		"--- |\n  first\n  second\n", "--- # authored\nsetting: value\n",
		"setting: value\n", "%YAML 1.1\n--- {setting: value}\n",
	} {
		t.Run(native, func(t *testing.T) {
			var want any
			if err := yaml.Unmarshal([]byte(native), &want); err != nil {
				t.Fatal(err)
			}
			framed, _ := frameEffectiveYAML("app", []byte(native))
			withoutLabel := bytes.Replace(framed, []byte("# scope: app\n"), nil, 1)
			if !strings.HasPrefix(native, "---") && !strings.HasPrefix(native, "%") {
				withoutLabel = bytes.TrimPrefix(withoutLabel, []byte("---\n"))
			}
			if !bytes.Equal(withoutLabel, []byte(native)) {
				t.Fatalf("native content changed: %q", framed)
			}
			if !bytes.Contains(framed, []byte("# scope: app\n")) {
				t.Fatalf("missing label: %q", framed)
			}
			decoder := yaml.NewDecoder(bytes.NewReader(framed))
			var got any
			if err := decoder.Decode(&got); err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(got, want) {
				t.Fatalf("got=%#v want=%#v", got, want)
			}
			if err := decoder.Decode(new(any)); err != io.EOF {
				t.Fatalf("extra document: %v", err)
			}
		})
	}
}

func TestEffectiveYAMLFramingPreservesBoundariesAndDirectives(t *testing.T) {
	for _, test := range []struct {
		name      string
		scope     string
		native    string
		directive bool
		label     string
	}{
		{name: "no trailing newline", scope: "app", native: "value: plain", label: "# scope: app\n"},
		{name: "CRLF", scope: "app", native: "# authored\r\n---\r\nvalue: yes\r\n", label: "# scope: app\n"},
		{name: "directive preamble", scope: "app", native: "%YAML 1.1\n# authored\n---\nvalue: yes", directive: true, label: "# scope: app\n"},
		{name: "control character label", scope: "line\nbreak", native: "value: yes", label: "# scope: \"line\\nbreak\"\n"},
	} {
		t.Run(test.name, func(t *testing.T) {
			var want any
			if err := yaml.Unmarshal([]byte(test.native), &want); err != nil {
				t.Fatal(err)
			}
			framed, hasDirective := frameEffectiveYAML(test.scope, []byte(test.native))
			if hasDirective != test.directive {
				t.Fatalf("hasDirective = %t, want %t", hasDirective, test.directive)
			}
			withoutLabel := bytes.Replace(framed, []byte(test.label), nil, 1)
			if !strings.HasPrefix(test.native, "---") && !strings.HasPrefix(test.native, "%") {
				withoutLabel = bytes.TrimPrefix(withoutLabel, []byte("---\n"))
			}
			if !bytes.Equal(withoutLabel, []byte(test.native)) {
				t.Fatalf("native content changed: got %q want %q", withoutLabel, test.native)
			}
			if !bytes.Contains(framed, []byte(test.label)) {
				t.Fatalf("missing scope label %q in %q", test.label, framed)
			}
			decoder := yaml.NewDecoder(bytes.NewReader(framed))
			var first any
			if err := decoder.Decode(&first); err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(first, want) {
				t.Fatalf("decoded value = %#v, want %#v", first, want)
			}
			if err := decoder.Decode(new(any)); err != io.EOF {
				t.Fatalf("unexpected extra YAML document: %v", err)
			}
		})
	}
}