package commandkit

import (
	"reflect"
	"testing"

	commandmeta "go.maximumdirect.net/commandkit/internal/commandmeta"
)

func TestCompletionFlagAndValuePositions(t *testing.T) {
	parse := func(value string) (string, error) { return value, nil }
	choice := CompleteChoices(CompletionChoice{Value: "blue"}, CompletionChoice{Value: "green"})
	command := NewCommand(CommandSpec[struct{}]{
		Name: "run",
		Flags: []Flag[struct{}]{
			ValueFlag(FlagMeta{Name: "color", Short: "c", Completion: choice}, (*string)(nil), parse, func(*struct{}, Supplied[string]) {}),
			RepeatFlag(FlagMeta{Name: "tag", Short: "t", Completion: choice}, nil, parse, func(*struct{}, Supplied[[]string]) {}),
			BoolFlag(FlagMeta{Name: "switch", Short: "s"}, false, func(*struct{}, Supplied[bool]) {}),
		},
		Run: func(Invocation, struct{}) Outcome { return Success() },
	})
	app, err := New(Identity{Name: "example"}, command,
		FlagAliasFor("run", "--colour", "--color"), FlagAliasFor("run", "-C", "--color"), FlagAlias("-v", "--verbose"))
	if err != nil {
		t.Fatal(err)
	}
	snapshot := app.routeSnapshot()
	for _, tc := range []struct {
		name, current, prefix, value string
		completed                    []string
		kind                         completionTargetKind
		hint                         commandmeta.CompletionKind
	}{
		{"pending takes option", "--quiet", "", "--quiet", []string{"run", "--color"}, completionTargetValue, commandmeta.CompletionChoices},
		{"terminator consumed as value", "-x", "", "-x", []string{"run", "--color", "--", "--tag"}, completionTargetValue, commandmeta.CompletionChoices},
		{"repeated singleton value", "--color=gr", "--color=", "gr", []string{"run", "--color=blue"}, completionTargetValue, commandmeta.CompletionChoices},
		{"long alias value", "--colour=bl", "--colour=", "bl", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"long empty value", "--color=", "--color=", "", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"short alias value", "-sCbl", "-sC", "bl", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"short equals", "-sC=bl", "-sC=", "bl", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"reporting boolean", "--verbose=f", "--verbose=", "f", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"short boolean alias", "-v=f", "-v=", "f", []string{"run"}, completionTargetValue, commandmeta.CompletionChoices},
		{"application boolean", "--switch=f", "--switch=", "f", []string{"run"}, completionTargetValue, commandmeta.CompletionNone},
		{"scoped alias unavailable at root", "--colour=bl", "", "", nil, completionTargetNone, commandmeta.CompletionNone},
		{"unknown completed", "--c", "", "", []string{"run", "--unknown"}, completionTargetNone, commandmeta.CompletionNone},
		{"unknown attached", "--unknown=x", "", "", []string{"run"}, completionTargetNone, commandmeta.CompletionNone},
		{"terminator", "--color", "", "", []string{"run", "--"}, completionTargetNone, commandmeta.CompletionNone},
	} {
		t.Run(tc.name, func(t *testing.T) {
			target := completionTargetFor(snapshot, resolveCompletionContext(snapshot, tc.completed, tc.current))
			if target.kind != tc.kind || target.hint.Kind != tc.hint || target.prefix != tc.prefix || target.valuePrefix != tc.value {
				t.Fatalf("target=%#v", target)
			}
		})
	}

	context := resolveCompletionContext(snapshot, []string{"run", "--colour=blue", "--tag=one", "--verbose"}, "--")
	target := completionTargetFor(snapshot, context)
	names := completionChoiceNames(target.choices)
	if containsCompletionName(names, "--color") || !containsCompletionName(names, "--tag") || !containsCompletionName(names, "--verbose") {
		t.Fatalf("flag suggestions=%q", names)
	}
	cluster := completionTargetFor(snapshot, resolveCompletionContext(snapshot, []string{"run"}, "-sv"))
	if cluster.kind != completionTargetFlags || !containsCompletionName(completionChoiceNames(cluster.choices), "-svc") || containsCompletionName(completionChoiceNames(cluster.choices), "-svs") {
		t.Fatalf("short cluster=%#v", cluster)
	}
	dash := completionTargetFor(snapshot, resolveCompletionContext(snapshot, []string{"run"}, "-"))
	if !containsCompletionName(completionChoiceNames(dash.choices), "--color") || !containsCompletionName(completionChoiceNames(dash.choices), "-c") {
		t.Fatalf("dash suggestions=%#v", dash)
	}
}

func TestCompletionOperandAllocation(t *testing.T) {
	arguments := []commandmeta.Argument{
		{Name: "optional", Min: 0, Max: 1, Completion: commandmeta.CompletionHint{Kind: commandmeta.CompletionFiles}},
		{Name: "repeated", Min: 0, Max: -1, Completion: commandmeta.CompletionHint{Kind: commandmeta.CompletionDirectories}},
		{Name: "required", Min: 1, Max: 1, Completion: commandmeta.BooleanCompletion()},
	}
	for _, tc := range []struct {
		completed int
		want      commandmeta.CompletionKind
	}{
		{0, commandmeta.CompletionChoices},
		{1, commandmeta.CompletionChoices},
		{2, commandmeta.CompletionChoices},
	} {
		hint, ok := completionOperandHint(arguments, tc.completed)
		if !ok || hint.Kind != tc.want {
			t.Fatalf("%d operands: %#v, %v", tc.completed, hint, ok)
		}
	}
	bounded := []commandmeta.Argument{{Name: "only", Max: 1, Completion: commandmeta.BooleanCompletion()}}
	if _, ok := completionOperandHint(bounded, 1); ok {
		t.Fatal("excess operand received a hint")
	}
	trailing := []commandmeta.Argument{{Name: "first", Min: 1, Max: 1, Completion: commandmeta.BooleanCompletion()}, {Name: "rest", Min: 0, Max: -1, Completion: commandmeta.CompletionHint{Kind: commandmeta.CompletionDirectories}}}
	if hint, ok := completionOperandHint(trailing, 1); !ok || hint.Kind != commandmeta.CompletionDirectories {
		t.Fatalf("repeated trailing operand: %#v, %v", hint, ok)
	}
	if got, want := completionChoiceNames(commandmeta.BooleanCompletion().Choices), []string{"true", "false"}; !reflect.DeepEqual(got, want) {
		t.Fatalf("boolean choices=%q", got)
	}
}

func TestCompletionOperandAndFlagContexts(t *testing.T) {
	command := &commandmeta.Command{
		Arguments: []commandmeta.Argument{{Name: "item", Min: 0, Max: 1, Completion: commandmeta.CompletionHint{Kind: commandmeta.CompletionFiles}}},
		Flags:     []commandmeta.Flag{{Name: "name", Completion: commandmeta.BooleanCompletion()}},
	}
	for _, tc := range []struct {
		name, current string
		tail          []string
		kind          completionTargetKind
		hint          commandmeta.CompletionKind
	}{
		{"empty chooses operand", "", nil, completionTargetOperand, commandmeta.CompletionFiles},
		{"dash chooses flag", "--n", nil, completionTargetFlags, commandmeta.CompletionNone},
		{"after terminator", "--n", []string{"--"}, completionTargetOperand, commandmeta.CompletionFiles},
		{"interspersed flag value", "value", []string{"--name", "--quiet"}, completionTargetOperand, commandmeta.CompletionFiles},
		{"excess operand", "value", []string{"already"}, completionTargetNone, commandmeta.CompletionNone},
	} {
		t.Run(tc.name, func(t *testing.T) {
			target := completionTargetFor(nil, completionContext{command: command, tail: tc.tail, current: tc.current})
			if target.kind != tc.kind || target.hint.Kind != tc.hint {
				t.Fatalf("target=%#v", target)
			}
		})
	}
}

func completionChoiceNames(choices []commandmeta.CompletionChoice) []string {
	var names []string
	for _, choice := range choices {
		names = append(names, choice.Value)
	}
	return names
}

func containsCompletionName(names []string, want string) bool {
	for _, name := range names {
		if name == want {
			return true
		}
	}
	return false
}