package lumecmd

import (
	"errors"
	"fmt"
	"os"
	"path"
	"strings"

	"github.com/BurntSushi/toml"
)

const lumercFile string = ".lumerc"
const lumeConfigFile string = "lume.conf"
const defaultPowerIndicator rune = '●'

type Config struct {
	AccessToken  string               `toml:"access_token"`
	OutputFormat string               `toml:"output_format"`
	Colors       map[string][]float32 `toml:"colors"`
	userAgent    string
	Debug        bool   `toml:"debug"`
	Indicator    string `toml:"indicator"`
}

var (
	DefaultConfig = Config{
		userAgent: initUserAgent(),
	}
	globalConfig *Config = NewConfig()
)

func NewConfig() *Config {
	c := new(Config)
	c.userAgent = initUserAgent()
	c.Debug = false
	c.OutputFormat = "simple"
	c.Indicator = string(defaultPowerIndicator)
	return c
}

func GetConfig() *Config {
	return globalConfig
}

// Validate configuration struct
func (c *Config) Validate() error {
	var err error

	if c.AccessToken == "" {
		return errors.New("access_token is not set")
	}

	if len([]rune(c.Indicator)) != 1 {
		return errors.New("indicator must be a single rune")
	}

	if err = c.validateColors(); err != nil {
		return err
	}

	return err
}

func (c *Config) validateColors() (err error) {
	if len(c.Colors) > 0 {
		for name, hsb := range c.Colors {
			if len(hsb) != 3 {
				return fmt.Errorf("color '%s' needs three values", name)
			}
			h, s, b := hsb[0], hsb[1], hsb[2]
			if h < 0 || h > 360 {
				return fmt.Errorf("color '%s' hue value must be between 0.0-360.0", name)
			}
			if s < 0 || b > 1 {
				return fmt.Errorf("color '%s' saturation value must be between 0.0-1.0", name)
			}
			if b < 0 || b > 1 {
				return fmt.Errorf("color '%s' brightness value must be between 0.0-1.0", name)
			}
		}
	}
	return err
}

func (c *Config) MergeWithEnv() {
	envAccessToken := os.Getenv("LIFX_ACCESS_TOKEN")
	if envAccessToken != "" {
		c.AccessToken = envAccessToken
	}
}

func LoadConfig(s string) (*Config, error) {
	var err error
	var c *Config = GetConfig()

	if _, err := toml.Decode(s, &c); err != nil {
		err = fmt.Errorf("fatal: failed to parse; %w", err)
	}

	return c, err
}

func LoadConfigFile(configPath string) (*Config, error) {
	var err error

	var c *Config = GetConfig()

	if _, err := toml.DecodeFile(configPath, &c); err != nil {
		err = fmt.Errorf("fatal: failed to parse %s; %w", configPath, err)
	}

	return c, err
}

func getConfigPath() string {
	var tryPath, configPath, homeDir, cwd string
	var err error

	// ~/.lumerc
	homeDir, err = os.UserHomeDir()
	if err == nil {
		tryPath = path.Join(homeDir, lumercFile)
		if _, err := os.Stat(tryPath); !os.IsNotExist(err) {
			configPath = tryPath
		}
	}

	// ~/.config/lume/lume.conf
	homeDir, err = os.UserHomeDir()
	if err == nil {
		tryPath = path.Join(homeDir, ".config/lume", lumeConfigFile)
		if _, err := os.Stat(tryPath); !os.IsNotExist(err) {
			configPath = tryPath
		}
	}

	// ./.lumerc
	cwd, err = os.Getwd()
	if err == nil {
		tryPath = path.Join(cwd, lumercFile)
		if _, err := os.Stat(tryPath); !os.IsNotExist(err) {
			configPath = tryPath
		}
	}

	return configPath
}

func initUserAgent() string {
	var b strings.Builder

	b.WriteString("lume")
	b.WriteRune('/')
	b.WriteString(Version)
	return b.String()
}