package commandkit

import (
	"testing"
)

type registryInput struct {
	value string
}

func TestNewAndRegisterRetainCallbacksWithoutCallingThem(t *testing.T) {
	var factoryCalls, prepareCalls, setterCalls, checkCalls, runCalls int
	flag := Flag[registryInput]{binding: flagBinding[registryInput]{
		meta:  FlagMeta{Name: "mode"},
		valid: true,
		prepare: func([]string) (func(*registryInput), error) {
			prepareCalls++
			return func(*registryInput) { setterCalls++ }, nil
		},
	}}
	command, err := NewCommand(CommandSpec[registryInput]{
		Name: "Inspect",
		NewInput: func() registryInput {
			factoryCalls++
			return registryInput{}
		},
		Flags: []Flag[registryInput]{flag},
		CheckInput: func(registryInput) error {
			checkCalls++
			return nil
		},
		Run: func(Invocation, registryInput) Outcome {
			runCalls++
			return Success()
		},
	})
	if err != nil {
		t.Fatal(err)
	}
	group, err := Group("Tools", "tools", command)
	if err != nil {
		t.Fatal(err)
	}
	app, err := New(Identity{Name: "Example"}, group)
	if err != nil {
		t.Fatal(err)
	}
	if err := app.Register(); err != nil {
		t.Fatal(err)
	}

	if factoryCalls+prepareCalls+setterCalls+checkCalls+runCalls != 0 {
		t.Fatalf("construction invoked a callback: factory=%d prepare=%d setter=%d check=%d run=%d", factoryCalls, prepareCalls, setterCalls, checkCalls, runCalls)
	}
	if !app.commands["Tools"].command.children[0].payload.hasRun() {
		t.Fatal("registered command lost its handler")
	}
}

func TestAppsHaveIndependentRegistries(t *testing.T) {
	first, err := New(Identity{Name: "First"})
	if err != nil {
		t.Fatal(err)
	}
	second, err := New(Identity{Name: "Second"})
	if err != nil {
		t.Fatal(err)
	}
	command, err := NewCommand(CommandSpec[struct{}]{Name: "custom"})
	if err != nil {
		t.Fatal(err)
	}
	if err := first.Register(command); err != nil {
		t.Fatal(err)
	}
	if _, exists := second.commands["custom"]; exists {
		t.Fatal("registration leaked to another app")
	}
	if !first.commands["help"].reserved || !first.commands["version"].reserved {
		t.Fatal("New did not reserve generated root commands")
	}
}

func TestCommandAndGroupNames(t *testing.T) {
	for _, name := range []string{"", "--", "-option", "two words", " leading", "trailing "} {
		if _, err := NewCommand(CommandSpec[struct{}]{Name: name}); err == nil {
			t.Errorf("NewCommand accepted invalid name %q", name)
		}
	}
	if _, err := NewCommand(CommandSpec[struct{}]{Name: "CamelCase"}); err != nil {
		t.Fatalf("NewCommand rejected a custom mixed-case name: %v", err)
	}

	first, err := NewCommand(CommandSpec[struct{}]{Name: "repeat"})
	if err != nil {
		t.Fatal(err)
	}
	second, err := NewCommand(CommandSpec[struct{}]{Name: "repeat"})
	if err != nil {
		t.Fatal(err)
	}
	if _, err := Group("parent", "", first, second); err == nil {
		t.Fatal("Group accepted duplicate sibling paths")
	}
	if _, err := Group("parent", "", Command{}); err == nil {
		t.Fatal("Group accepted an invalid child declaration")
	}
}

func TestWithChildrenRetainsRunnableParent(t *testing.T) {
	parent, err := NewCommand(CommandSpec[struct{}]{Name: "parent", Run: func(Invocation, struct{}) Outcome {
		return Success()
	}})
	if err != nil {
		t.Fatal(err)
	}
	child, err := NewCommand(CommandSpec[struct{}]{Name: "child"})
	if err != nil {
		t.Fatal(err)
	}
	composed, err := WithChildren(parent, child)
	if err != nil {
		t.Fatal(err)
	}
	if composed.payload == nil || !composed.payload.hasRun() {
		t.Fatal("WithChildren did not retain the runnable parent")
	}
	if len(composed.children) != 1 || composed.children[0].name != "child" {
		t.Fatalf("children = %#v, want relative child declaration", composed.children)
	}
	if len(parent.children) != 0 {
		t.Fatal("WithChildren changed the original parent declaration")
	}
}

func TestRegisterBatchIsAtomicAndRejectsReservedPaths(t *testing.T) {
	app, err := New(Identity{Name: "Example"})
	if err != nil {
		t.Fatal(err)
	}
	existing, err := NewCommand(CommandSpec[struct{}]{Name: "existing"})
	if err != nil {
		t.Fatal(err)
	}
	if err := app.Register(existing); err != nil {
		t.Fatal(err)
	}
	before := app.commands["existing"]
	added, err := NewCommand(CommandSpec[struct{}]{Name: "added"})
	if err != nil {
		t.Fatal(err)
	}
	if err := app.Register(added, existing); err == nil {
		t.Fatal("Register accepted a duplicate path")
	}
	if app.commands["existing"] != before {
		t.Fatal("failed batch changed an existing registration")
	}
	if _, exists := app.commands["added"]; exists {
		t.Fatal("failed batch attached a partial registration")
	}
	if err := app.Register(added, added); err == nil {
		t.Fatal("Register accepted a duplicate within a batch")
	}
	if _, exists := app.commands["added"]; exists {
		t.Fatal("failed duplicate batch attached a registration")
	}
	for _, name := range []string{"help", "version"} {
		reserved, err := NewCommand(CommandSpec[struct{}]{Name: name})
		if err != nil {
			t.Fatal(err)
		}
		if err := app.Register(reserved); err == nil {
			t.Errorf("Register replaced reserved command %q", name)
		}
	}
}

func TestNewRejectsEmptyIdentityAndInvalidBindingMetadata(t *testing.T) {
	if _, err := New(Identity{}); err == nil {
		t.Fatal("New accepted an empty identity name")
	}

	validFlag := func(name, short string) Flag[registryInput] {
		return Flag[registryInput]{binding: flagBinding[registryInput]{
			meta:    FlagMeta{Name: name, Short: short},
			valid:   true,
			prepare: func([]string) (func(*registryInput), error) { return func(*registryInput) {}, nil },
		}}
	}
	for _, flags := range [][]Flag[registryInput]{
		{validFlag("one", "x"), validFlag("one", "y")},
		{validFlag("one", "x"), validFlag("two", "x")},
		{validFlag("help", "")},
		{validFlag("SomeFlag", "")},
		{validFlag("some_flag", "")},
		{validFlag("some--flag", "")},
		{{binding: flagBinding[registryInput]{meta: FlagMeta{Name: "missing"}}}},
	} {
		if _, err := NewCommand(CommandSpec[registryInput]{Name: "flags", Flags: flags}); err == nil {
			t.Errorf("NewCommand accepted invalid flag metadata: %#v", flags)
		}
	}

	badArgument := Argument[registryInput]{binding: argumentBinding[registryInput]{
		meta:    ArgumentMeta{Name: "item"},
		min:     2,
		max:     1,
		valid:   true,
		prepare: func([]string) (func(*registryInput), error) { return func(*registryInput) {}, nil },
	}}
	if _, err := NewCommand(CommandSpec[registryInput]{Name: "args", Arguments: []Argument[registryInput]{badArgument}}); err == nil {
		t.Fatal("NewCommand accepted invalid argument bounds")
	}
}

func TestNewCommandCopiesBindingMetadata(t *testing.T) {
	flags := []Flag[registryInput]{{binding: flagBinding[registryInput]{
		meta:    FlagMeta{Name: "mode"},
		valid:   true,
		prepare: func([]string) (func(*registryInput), error) { return func(*registryInput) {}, nil },
	}}}
	command, err := NewCommand(CommandSpec[registryInput]{Name: "run", Flags: flags})
	if err != nil {
		t.Fatal(err)
	}
	flags[0].binding.meta.Name = "changed"
	payload := command.payload.(typedCommand[registryInput])
	if got := payload.spec.Flags[0].binding.meta.Name; got != "mode" {
		t.Fatalf("stored flag name = %q, want %q", got, "mode")
	}
}