package cmd

import (
	"io"
	"os"

	"go.fifitido.net/cmd/opt"
)

var outputFileOption = opt.String("output", "o", "", "The file to output the completions to")

func CompletionsSubcommand() *Command {
	cmd := New(
		"completions",
		WithShortDescription("Generate shell completions"),
		WithLongDescription("Generate shell completions"),
	)

	registerBashCompletions(cmd)
	registerFishCompletions(cmd)
	registerPowerShellCompletions(cmd)
	registerZsgCompletions(cmd)

	return cmd
}

func getCompletionsOut() io.Writer {
	outputFile := outputFileOption.Value()

	if outputFile != "" {
		var err error
		out, err := os.OpenFile(outputFile, os.O_WRONLY|os.O_CREATE, 0644)
		if err != nil {
			panic(err)
		}
		return out
	}

	return os.Stdout
}

func registerBashCompletions(parent *Command) *Command {
	return New(
		"bash",
		WithShortDescription("Generate bash completions"),
		WithLongDescription("Generate bash completions"),
		WithOptions(outputFileOption),
		WithParent(parent),
		WithRunFunc(func(args []string) {
			out := getCompletionsOut()

			if fc, ok := out.(io.Closer); ok {
				defer fc.Close()
			}

			if err := WriteBashCompletions(out, parent.Root()); err != nil {
				panic(err)
			}
		}),
	)
}

func registerFishCompletions(parent *Command) *Command {
	return New(
		"fish",
		WithShortDescription("Generate fish completions"),
		WithLongDescription("Generate fish completions"),
		WithOptions(outputFileOption),
		WithParent(parent),
		WithRunFunc(func(args []string) {
			out := getCompletionsOut()

			if fc, ok := out.(io.Closer); ok {
				defer fc.Close()
			}

			if err := WriteFishCompletions(out, parent.Root()); err != nil {
				panic(err)
			}
		}),
	)
}

func registerPowerShellCompletions(parent *Command) *Command {
	return New(
		"powershell",
		WithShortDescription("Generate powershell completions"),
		WithLongDescription("Generate powershell completions"),
		WithOptions(outputFileOption),
		WithParent(parent),
		WithRunFunc(func(args []string) {
			out := getCompletionsOut()

			if fc, ok := out.(io.Closer); ok {
				defer fc.Close()
			}

			if err := WritePowerShellCompletions(out, parent.Root()); err != nil {
				panic(err)
			}
		}),
	)
}

func registerZsgCompletions(parent *Command) *Command {
	return New(
		"zsh",
		WithShortDescription("Generate zsh completions"),
		WithLongDescription("Generate zsh completions"),
		WithOptions(outputFileOption),
		WithParent(parent),
		WithRunFunc(func(args []string) {
			out := getCompletionsOut()

			if fc, ok := out.(io.Closer); ok {
				defer fc.Close()
			}

			if err := WriteZshCompletions(out, parent.Root()); err != nil {
				panic(err)
			}
		}),
	)
}