package configkit_test

import (
	"embed"
	"io/fs"
	"reflect"
	"strconv"
	"strings"
	"testing"
	"testing/fstest"

	configkit "gitea.maximumdirect.net/eric/ConfigKit"
)

//go:embed testdata/filesystem
var filesystemFixtures embed.FS

type filesystemFacadeConfig struct {
	Items map[string]string `yaml:"items"`
}

func TestFacadeFilesystemSourceImportsOverlayAndReuse(t *testing.T) {
	fixture, err := fs.Sub(filesystemFixtures, "testdata/filesystem")
	if err != nil {
		t.Fatal(err)
	}
	namespace := configkit.NewFilesystem("embedded", fixture)
	copyOfNamespace := namespace
	source := namespace.File("config/main.yml")
	for range 2 {
		result, err := configkit.Load(source, configkit.Options[filesystemFacadeConfig]{
			Imports: true, Overlay: "testing", Filesystem: &configkit.FilesystemContext{FS: &copyOfNamespace},
		})
		if err != nil {
			t.Fatal(err)
		}
		if want := (map[string]string{"main": "selected", "shared": "default"}); !reflect.DeepEqual(result.Config.Items, want) {
			t.Fatalf("items = %#v, want %#v", result.Config.Items, want)
		}
		sources := result.Sources()
		if len(sources) != 3 {
			t.Fatalf("sources = %#v", sources)
		}
		for index, want := range []string{"config/main.yml", "shared.yml", "overlays/testing.yml"} {
			if sources[index].ID != "source-"+strconv.Itoa(index+1) || sources[index].Path != want || sources[index].Kind != configkit.SourceKindFilesystem {
				t.Errorf("source %d = %#v", index, sources[index])
			}
			if sources[index].Label != "embedded/"+want {
				t.Errorf("source label = %q", sources[index].Label)
			}
		}
		if sources[1].ImportedFrom == nil || sources[1].ImportedFrom.SourceID != sources[0].ID || sources[1].ImportedFrom.Line == 0 {
			t.Fatalf("import location = %#v", sources[1].ImportedFrom)
		}
	}
}

func TestFacadeFilesystemContextsAndIdentity(t *testing.T) {
	first := configkit.NewFilesystem("same", fstest.MapFS{
		"root/config/main.yml":      &fstest.MapFile{Data: []byte("configkit: {imports: [{path: ../shared.yml}]}\n")},
		"root/shared.yml":           &fstest.MapFile{Data: []byte("items: {value: first}\n")},
		"root/overlays/testing.yml": &fstest.MapFile{Data: []byte("items: {overlay: first}\n")},
	})
	second := configkit.NewFilesystem("same", fstest.MapFS{
		"root/config/main.yml": &fstest.MapFile{Data: []byte("items: {value: second}\n")},
	})
	context := &configkit.FilesystemContext{Root: "root", FS: &first}
	result, err := configkit.Load(first.File("root/config/main.yml"), configkit.Options[filesystemFacadeConfig]{Imports: true, Overlay: "testing", Filesystem: context})
	if err != nil || result.Config.Items["value"] != "first" || result.Config.Items["overlay"] != "first" {
		t.Fatalf("contained load = %#v, %v", result, err)
	}
	result, err = configkit.Load[filesystemFacadeConfig](second.File("root/config/main.yml"))
	if err != nil || result.Config.Items["value"] != "second" {
		t.Fatalf("same-label independent namespace = %#v, %v", result, err)
	}
	checkCode(t, second.File("root/config/main.yml"), configkit.Options[filesystemFacadeConfig]{Filesystem: context}, configkit.CodeOptionsInvalid)
	checkCode(t, first.File("root/config/main.yml"), configkit.Options[filesystemFacadeConfig]{Filesystem: &configkit.FilesystemContext{Root: "root/config", FS: &first}, Imports: true}, configkit.CodeImportOutsideRoot)
	checkCode(t, configkit.File("testdata/filesystem/config/main.yml"), configkit.Options[filesystemFacadeConfig]{Filesystem: context}, configkit.CodeOptionsInvalid)

	for _, input := range []struct {
		name   string
		source configkit.Source
		kind   configkit.SourceKind
	}{
		{"bytes", configkit.Bytes("memory", []byte("configkit: {imports: [{path: shared.yml}]}\n")), configkit.SourceKindBytes},
		{"reader", configkit.Reader("stream", strings.NewReader("configkit: {imports: [{path: shared.yml}]}\n")), configkit.SourceKindReader},
	} {
		t.Run(input.name, func(t *testing.T) {
			result, err := configkit.Load(input.source, configkit.Options[filesystemFacadeConfig]{Imports: true, Filesystem: &configkit.FilesystemContext{Root: "root", BaseDir: "root", FS: &first}})
			if err != nil || result.Config.Items["value"] != "first" {
				t.Fatalf("synthetic import = %#v, %v", result, err)
			}
			if got := result.Sources(); len(got) != 2 || got[0].Kind != input.kind || got[0].Path != "" || got[1].Kind != configkit.SourceKindFilesystem {
				t.Fatalf("sources = %#v", got)
			}
		})
	}
	checkCode(t, configkit.Bytes("memory", []byte("items: {}\n")), configkit.Options[filesystemFacadeConfig]{Filesystem: &configkit.FilesystemContext{Root: "root", BaseDir: ".", FS: &first}}, configkit.CodeImportOutsideRoot)
	result, err = configkit.Load(configkit.Bytes("memory", []byte("items: {value: main}\n")), configkit.Options[filesystemFacadeConfig]{
		Overlay: "testing", Filesystem: &configkit.FilesystemContext{Root: "root", BaseDir: "root", FS: &first},
	})
	if err != nil || result.Config.Items["value"] != "main" || result.Config.Items["overlay"] != "first" {
		t.Fatalf("synthetic selected overlay = %#v, %v", result, err)
	}
}

func TestFacadeSourceKindsIncludeHostAndCLI(t *testing.T) {
	result, err := configkit.Load(configkit.File("testdata/filesystem/shared.yml"), configkit.Options[filesystemFacadeConfig]{
		Overrides: []configkit.Override{{Path: configkit.Keys("items", "shared"), Value: "changed", Flag: "--shared"}},
	})
	if err != nil {
		t.Fatal(err)
	}
	sources := result.Sources()
	if len(sources) != 2 || sources[0].Kind != configkit.SourceKindFile || sources[0].Path == "" || sources[1].Kind != configkit.SourceKindCLI || sources[1].Path != "" {
		t.Fatalf("host and CLI sources = %#v", sources)
	}
}

func TestFacadeFilesystemConstructorDiagnostics(t *testing.T) {
	var nilFilesystem fs.FS
	var zero configkit.Filesystem
	for _, source := range []configkit.Source{
		zero.File("main.yml"),
		configkit.NewFilesystem("", fstest.MapFS{}).File("main.yml"),
		configkit.NewFilesystem("bad\nlabel", fstest.MapFS{}).File("main.yml"),
		configkit.NewFilesystem("good", nilFilesystem).File("main.yml"),
		configkit.NewFilesystem("good", fstest.MapFS{}).File("."),
		configkit.NewFilesystem("good", fstest.MapFS{}).File("../outside.yml"),
	} {
		checkCode(t, source, configkit.Options[filesystemFacadeConfig]{}, configkit.CodeSourceInvalid)
	}
}

func checkCode(t *testing.T, source configkit.Source, options configkit.Options[filesystemFacadeConfig], want configkit.Code) {
	t.Helper()
	_, err := configkit.Load(source, options)
	loadError, ok := err.(*configkit.LoadError)
	if !ok || len(loadError.Diagnostics()) == 0 || loadError.Diagnostics()[0].Code != want {
		t.Fatalf("error = %#v, want %s", err, want)
	}
}