package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/user"
	"path/filepath"

	"github.com/liamg/aminal/config"
	"github.com/liamg/aminal/version"
)

func getActuallyProvidedFlags() map[string]bool {
	result := make(map[string]bool)

	flag.Visit(func(f *flag.Flag) {
		result[f.Name] = true
	})

	return result
}

func getConfig() *config.Config {
	showVersion := false
	ignoreConfig := false
	shell := ""
	debugMode := false
	slomo := false

	if flag.Parsed() == false {
		flag.BoolVar(&showVersion, "version", showVersion, "Output version information")
		flag.BoolVar(&ignoreConfig, "ignore-config", ignoreConfig, "Ignore user config files and use defaults")
		flag.StringVar(&shell, "shell", shell, "Specify the shell to use")
		flag.BoolVar(&debugMode, "debug", debugMode, "Enable debug logging")
		flag.BoolVar(&slomo, "slomo", slomo, "Render in slow motion (useful for debugging)")

		flag.Parse() // actual parsing and fetching flags from the command line
	}
	actuallyProvidedFlags := getActuallyProvidedFlags()

	if showVersion {
		v := version.Version
		if v == "" {
			v = "development"
		}
		fmt.Println(v)
		os.Exit(0)
	}

	var conf *config.Config
	if ignoreConfig {
		conf = &config.DefaultConfig
	} else {
		conf = loadConfigFile()
	}

	// Override values in the configuration file with the values specified in the command line, if any.
	if actuallyProvidedFlags["shell"] {
		conf.Shell = shell
	}

	if actuallyProvidedFlags["debug"] {
		conf.DebugMode = debugMode
	}

	if actuallyProvidedFlags["slomo"] {
		conf.Slomo = slomo
	}

	return conf
}

func loadConfigFile() *config.Config {

	usr, err := user.Current()
	if err != nil {
		fmt.Printf("Failed to get current user information: %s\n", err)
		return &config.DefaultConfig
	}

	home := usr.HomeDir
	if home == "" {
		return &config.DefaultConfig
	}

	places := []string{}

	xdgHome := os.Getenv("XDG_CONFIG_HOME")
	if xdgHome != "" {
		places = append(places, filepath.Join(xdgHome, "aminal/config.toml"))
	}

	places = append(places, filepath.Join(home, ".config/aminal/config.toml"))
	places = append(places, filepath.Join(home, ".aminal.toml"))

	for _, place := range places {
		if b, err := ioutil.ReadFile(place); err == nil {
			if c, err := config.Parse(b); err == nil {
				return c
			}

			fmt.Printf("Invalid config at %s: %s\n", place, err)
		}
	}

	if b, err := config.DefaultConfig.Encode(); err != nil {
		fmt.Printf("Failed to encode config file: %s\n", err)
	} else {
		err = os.MkdirAll(filepath.Dir(places[0]), 0744)
		if err != nil {
			fmt.Printf("Failed to create config file directory: %s\n", err)
		} else {
			if err = ioutil.WriteFile(places[0], b, 0644); err != nil {
				fmt.Printf("Failed to encode config file: %s\n", err)
			}
		}
	}

	return &config.DefaultConfig
}