package configkit_test

import (
	"os"
	"path/filepath"
	"testing"
	"testing/fstest"

	configkit "go.maximumdirect.net/configkit"
)

func TestMainRelativeCompanion(t *testing.T) {
	dir := t.TempDir()
	if err := os.WriteFile(filepath.Join(dir, "main.yml"), []byte("count: 3\n"), 0600); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "extra.yml"), []byte("settings: {companion: host}\n"), 0600); err != nil {
		t.Fatal(err)
	}
	binding := configkit.MainRelative()
	companion := configkit.Input{Source: configkit.Bytes("companions", []byte("config: {imports: [{path: extra.yml}]}\n")), Imports: true, MainRelative: binding}
	result, err := configkit.LoadLayered(configkit.Input{Source: configkit.File(filepath.Join(dir, "main.yml"))}, configkit.LayeredOptions[layeredFacadeConfig]{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{companion}}}})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 3 || result.Config.Settings["companion"] != "host" {
		t.Fatalf("configuration = %#v", result.Config)
	}
	native := configkit.NewFilesystem("bundle", fstest.MapFS{"dir/main.yml": &fstest.MapFile{Data: []byte("count: 4\n")}, "dir/extra.yml": &fstest.MapFile{Data: []byte("settings: {companion: native}\n")}})
	result, err = configkit.LoadLayered(configkit.Input{Source: native.File("dir/main.yml")}, configkit.LayeredOptions[layeredFacadeConfig]{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{companion}}}})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 4 || result.Config.Settings["companion"] != "native" {
		t.Fatalf("configuration = %#v", result.Config)
	}
}

func TestMainRelativeContextSelection(t *testing.T) {
	root := t.TempDir()
	base := filepath.Join(root, "main")
	if err := os.Mkdir(base, 0700); err != nil {
		t.Fatal(err)
	}
	for path, value := range map[string]string{"main/main.yml": "count: 1\n", "main/extra.yml": "settings: {value: derived}\n", "extra.yml": "settings: {value: fallback}\n"} {
		if err := os.WriteFile(filepath.Join(root, path), []byte(value), 0600); err != nil {
			t.Fatal(err)
		}
	}
	link := filepath.Join(root, "link.yml")
	if err := os.Symlink(filepath.Join(base, "main.yml"), link); err != nil {
		t.Fatal(err)
	}
	companion := configkit.Input{Source: configkit.Bytes("companion", []byte("config: {imports: [{path: extra.yml}]}\n")), Imports: true, MainRelative: &configkit.MainRelativeContext{Fallback: &configkit.FilesystemContext{Root: root, BaseDir: root}}}
	opts := configkit.LayeredOptions[layeredFacadeConfig]{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{companion}}}}
	result, err := configkit.LoadLayered(configkit.Input{Source: configkit.File(link), Filesystem: &configkit.FilesystemContext{Root: root}}, opts)
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if got := result.Config.Settings["value"]; got != "derived" {
		t.Fatalf("derived value = %q", got)
	}
	result, err = configkit.LoadLayered(configkit.Input{Source: configkit.NoSource()}, opts)
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if got := result.Config.Settings["value"]; got != "fallback" {
		t.Fatalf("fallback value = %q", got)
	}
}

func TestMainRelativeWithoutBase(t *testing.T) {
	tests := []struct {
		name, source string
		requireBase  bool
		wantCode     configkit.Code
	}{
		{"optional", "config: {imports: [{path: missing.yml}]}\ncount: 7\n", false, ""},
		{"required", "config: {imports: [{path: missing.yml, required: true}]}\n", false, configkit.CodeImportMissing},
		{"required directory", "config: {imports: [{dir: missing, required: true}]}\n", false, configkit.CodeImportMissing},
		{"required glob", "config: {imports: [{glob: '*.yml', required: true}]}\n", false, configkit.CodeImportMissing},
		{"empty required", "config: {imports: [{path: [], required: true}]}\ncount: 7\n", false, ""},
		{"base required", "count: 7\n", true, configkit.CodeOptionsInvalid},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			input := configkit.Input{Source: configkit.Bytes("companion", []byte(test.source)), Imports: true, MainRelative: &configkit.MainRelativeContext{RequireBase: test.requireBase}}
			result, err := configkit.LoadLayered(configkit.Input{Source: configkit.NoSource()}, configkit.LayeredOptions[layeredFacadeConfig]{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{input}}}})
			if test.wantCode != "" {
				if err == nil {
					t.Fatal("expected failure")
				}
				for _, d := range err.(*configkit.LoadError).Diagnostics() {
					if d.Code == test.wantCode {
						return
					}
				}
				t.Fatalf("diagnostics: %#v", err.(*configkit.LoadError).Diagnostics())
			}
			if err != nil {
				t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
			}
			if result.Config.Count != 7 {
				t.Fatalf("config = %#v", result.Config)
			}
			if sources := result.Sources(); len(sources) != 1 || len(sources[0].EmptyImportSelections) != 0 {
				t.Fatalf("sources = %#v", sources)
			}
		})
	}
}

func TestMainRelativeWithoutBaseSequenceItem(t *testing.T) {
	type item struct {
		Name string `yaml:"name"`
	}
	type config struct {
		Items []item `yaml:"items"`
	}
	input := configkit.Input{Source: configkit.Bytes("item", []byte("config: {imports: [{path: missing.yml}]}\nname: example\n")), Imports: true, MainRelative: configkit.MainRelative(), Destination: configkit.Keys("items"), PlacementMode: configkit.PlacementModeSequenceItem}
	result, err := configkit.LoadLayered(configkit.Input{Source: configkit.NoSource()}, configkit.LayeredOptions[config]{Underlays: []configkit.Underlay{{Inputs: []configkit.Input{input}}}})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if len(result.Config.Items) != 1 || result.Config.Items[0].Name != "example" {
		t.Fatalf("config = %#v", result.Config)
	}
}

func TestMainRelativeWithoutBaseImportDefaults(t *testing.T) {
	required := true
	tests := []struct {
		name, source string
		imports      bool
		requireBase  bool
		code         configkit.Code
	}{
		{"default required", "config: {imports: [{path: missing.yml}]}\n", true, false, configkit.CodeImportMissing},
		{"malformed", "config: {imports: [{path: 42}]}\n", true, false, configkit.CodeImportInvalid},
		{"imports disabled", "config: {imports: [{path: missing.yml}]}\n", false, false, configkit.CodeImportDisabled},
		{"base required without imports", "count: 1\n", false, true, configkit.CodeOptionsInvalid},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			input := configkit.Input{Source: configkit.Bytes("companion", []byte(test.source)), Imports: test.imports, MainRelative: &configkit.MainRelativeContext{RequireBase: test.requireBase}}
			_, err := configkit.LoadLayered(configkit.Input{Source: configkit.NoSource()}, configkit.LayeredOptions[layeredFacadeConfig]{ImportDefaults: configkit.ImportDefaults{Required: &required}, Underlays: []configkit.Underlay{{Inputs: []configkit.Input{input}}}})
			if err == nil {
				t.Fatal("expected failure")
			}
			for _, diagnostic := range err.(*configkit.LoadError).Diagnostics() {
				if diagnostic.Code == test.code {
					return
				}
			}
			t.Fatalf("diagnostics = %#v", err.(*configkit.LoadError).Diagnostics())
		})
	}
}

func TestLayeredOverlayContextSelection(t *testing.T) {
	root := t.TempDir()
	base := filepath.Join(root, "base")
	for _, dir := range []string{filepath.Join(root, "overlays"), filepath.Join(base, "overlays")} {
		if err := os.MkdirAll(dir, 0700); err != nil {
			t.Fatal(err)
		}
	}
	for path, content := range map[string]string{"base/main.yml": "count: 1\n", "base/overlays/test.yml": "count: 2\n", "overlays/test.yml": "count: 3\n"} {
		if err := os.WriteFile(filepath.Join(root, path), []byte(content), 0600); err != nil {
			t.Fatal(err)
		}
	}
	main := configkit.Input{Source: configkit.File(filepath.Join(base, "main.yml")), Filesystem: &configkit.FilesystemContext{Root: root}}
	result, err := configkit.LoadLayered(main, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "test"})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 2 {
		t.Fatalf("derived overlay = %d", result.Config.Count)
	}
	result, err = configkit.LoadLayered(main, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "test", OverlayFilesystem: &configkit.FilesystemContext{Root: root, BaseDir: base}})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 3 {
		t.Fatalf("explicit overlay = %d", result.Config.Count)
	}
	result, err = configkit.LoadLayered(configkit.Input{Source: configkit.NoSource()}, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "test", OverlayFallback: &configkit.FilesystemContext{Root: root, BaseDir: base}})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 2 {
		t.Fatalf("fallback overlay = %d", result.Config.Count)
	}
}

func TestLayeredOverlayNativeContext(t *testing.T) {
	filesystem := configkit.NewFilesystem("bundle", fstest.MapFS{
		"dir/main.yml":          &fstest.MapFile{Data: []byte("count: 1\n")},
		"dir/overlays/test.yml": &fstest.MapFile{Data: []byte("count: 9\n")},
	})
	main := configkit.Input{Source: filesystem.File("dir/main.yml"), Filesystem: &configkit.FilesystemContext{Root: ".", FS: &filesystem}}
	result, err := configkit.LoadLayered(main, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "test"})
	if err != nil {
		t.Fatalf("%v: %#v", err, err.(*configkit.LoadError).Diagnostics())
	}
	if result.Config.Count != 9 {
		t.Fatalf("config = %#v", result.Config)
	}
	_, err = configkit.LoadLayered(main, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "missing", OverlayFallback: &configkit.FilesystemContext{Root: ".", BaseDir: ".", FS: &filesystem}})
	if err == nil {
		t.Fatal("missing selected overlay succeeded")
	}
	for _, diagnostic := range err.(*configkit.LoadError).Diagnostics() {
		if diagnostic.Code == configkit.CodeOverlayMissing {
			return
		}
	}
	t.Fatalf("diagnostics = %#v", err.(*configkit.LoadError).Diagnostics())
}

func TestLayeredOverlayNativeLinks(t *testing.T) {
	for _, tc := range []struct {
		name, mainPath, target string
		want                   configkit.Code
	}{
		{"outside root", "scope/main.yml", "../../outside.yml", configkit.CodeOverlayOutsideRoot},
		{"overlay aliases main", "scope/main.yml", "../main.yml", configkit.CodeOverlayRepeated},
		{"main aliases overlay target", "scope/alias.yml", "../target.yml", configkit.CodeOverlayRepeated},
		{"contained overlay", "scope/main.yml", "../target.yml", ""},
	} {
		t.Run(tc.name, func(t *testing.T) {
			native := configkit.NewFilesystem("bundle", fstest.MapFS{
				"scope/main.yml":          {Data: []byte("count: 1\n")},
				"scope/alias.yml":         {Data: []byte("target.yml"), Mode: os.ModeSymlink},
				"scope/target.yml":        {Data: []byte("count: 7\n")},
				"scope/overlays/test.yml": {Data: []byte(tc.target), Mode: os.ModeSymlink},
				"outside.yml":             {Data: []byte("count: 9\n")},
			})
			main := configkit.Input{Source: native.File(tc.mainPath), Filesystem: &configkit.FilesystemContext{Root: "scope", FS: &native}}
			result, err := configkit.LoadLayered(main, configkit.LayeredOptions[layeredFacadeConfig]{Overlay: "test"})
			if tc.want != "" {
				if err == nil {
					t.Fatal("overlay link unexpectedly loaded")
				}
				diagnostics := err.(*configkit.LoadError).Diagnostics()
				if len(diagnostics) != 1 || diagnostics[0].Code != tc.want {
					t.Fatalf("diagnostics = %#v, want %v", diagnostics, tc.want)
				}
				return
			}
			if err != nil {
				t.Fatal(err)
			}
			if result.Config.Count != 7 || result.Sources()[1].Path != "scope/target.yml" {
				t.Fatalf("config = %#v, sources = %#v", result.Config, result.Sources())
			}
		})
	}
}