package main

import (
	"fmt"
	"os"
	"strings"
)

type Command struct {
	Name        string
	Description string
	Action      CommandAction
	Arguments   []string
	IsVarargs   bool
}

type CommandAction func([]string, []string) (string, error)

var commands = []Command{
	{
		Name:        "create",
		Description: "Registers the data directory path of game for management under the given name",
		Arguments:   []string{"data path", "game name"},
		IsVarargs:   false,

		Action: func(requiredArguments []string, providedArguments []string) (string, error) {
			if len(providedArguments) != len(requiredArguments) {
				return "", fmt.Errorf("expected %s folowed by %s",
					requiredArguments[0], requiredArguments[1])
			}

			var dataPath = providedArguments[0]
			var gameName = providedArguments[1]

			if registerGameError := CreateGame(gameName, dataPath); registerGameError != nil {
				return "", registerGameError
			}

			return fmt.Sprintf("Created %s at %s", gameName, dataPath), nil
		},
	},

	{
		Name:        "remove",
		Description: "Cleans and unregisters the given game name from management",
		Arguments:   []string{"game name"},
		IsVarargs:   false,

		Action: func(requiredArguments []string, providedArguments []string) (string, error) {
			if len(providedArguments) != len(requiredArguments) {
				return "", fmt.Errorf("expected %s", requiredArguments[0])
			}

			var dataPath = providedArguments[0]
			var gameName = providedArguments[1]

			if registerGameError := RemoveGame(gameName); registerGameError != nil {
				return "", registerGameError
			}

			return fmt.Sprintf("Removed %s at %s", gameName, dataPath), nil
		},
	},

	{
		Name:        "deploy",
		Description: "Deploys all specified mod archives in order of listing",
		Arguments:   []string{"game name", "archive paths"},
		IsVarargs:   true,

		Action: func(requiredArguments []string, providedArguments []string) (string, error) {
			if len(providedArguments) < len(requiredArguments) {
				return "", fmt.Errorf("expected %s followed by one or more %ss",
					requiredArguments[0], requiredArguments[1])
			}

			var deployError = DeployGameMods(providedArguments[0], providedArguments[1:])

			if deployError != nil {
				return "", deployError
			}

			return "deployed", nil
		},
	},

	{
		Name:        "clean",
		Description: "Clean all deployed mods",
		Arguments:   []string{"game name"},
		IsVarargs:   false,

		Action: func(requiredArguments []string, arguments []string) (string, error) {
			if len(arguments) != len(requiredArguments) {
				return "", fmt.Errorf("expected %s", requiredArguments[0])
			}

			var cleanError = CleanGameMods(arguments[0])

			if cleanError != nil {
				return "", cleanError
			}

			return "cleaned", nil
		},
	},

	{
		Name:        "list",
		Description: "List all known game associations by name followed by data path in a newline-separated list",
		Arguments:   []string{},
		IsVarargs:   false,

		Action: func(requiredArguments []string, arguments []string) (string, error) {
			if len(arguments) != 0 {
				return "", fmt.Errorf("expected zero arguments")
			}

			var gameDataPaths, loadError = LoadGames()

			if loadError != nil {
				return "", loadError
			}

			var stringBuilder = strings.Builder{}

			for game, dataPath := range gameDataPaths {
				if _, printError := fmt.Printf("%s %s\n", game, dataPath); printError != nil {
					return "", printError
				}
			}

			return stringBuilder.String(), nil
		},
	},
}

func main() {
	var argCount = len(os.Args)

	if argCount == 1 {
		fmt.Println("Modman v0.1")
		fmt.Println("Enter one of the following commands following modman:")

		for i := range commands {
			var command = commands[i]

			fmt.Print("\t", command.Name)

			for j := range command.Arguments {
				fmt.Print(" [", command.Arguments[j], "]")
			}

			if command.IsVarargs {
				fmt.Println("...")
			} else {
				fmt.Println()
			}
		}

		return
	}

	var commandName = os.Args[1]

	for i := range commands {
		var command = commands[i]

		if command.Name == commandName {
			var response, actionError = command.Action(command.Arguments, os.Args[2:])

			if actionError != nil {
				fmt.Fprintln(os.Stderr, actionError.Error())
				os.Exit(1)
			}

			if len(response) != 0 {
				fmt.Println(response)
			}

			return
		}
	}

	fmt.Fprintf(os.Stderr, "unknown command: `%s`\n", commandName)
}