package config

import (
	"encoding/json"
	"errors"
	"io/fs"
	"os"
	"path/filepath"
)

type Config struct {
	Base string `json:"base"`
}

func (c *Config) Workspace() string {
	return filepath.Join(c.Base, ".workspace")
}

func (c *Config) WorkspaceBranch(name string) string {
	return filepath.Join(c.Workspace(), name)
}

func (c *Config) IsInit() bool {
	return c.Base != ""
}

func path() (string, error) {
	userCfgDir, err := os.UserConfigDir()
	if err != nil {
		return "", err
	}
	cfgDir := filepath.Join(userCfgDir, "git-ea")
	return filepath.Join(cfgDir, "config.json"), os.MkdirAll(cfgDir, os.ModePerm)
}

func Load() (*Config, error) {
	cfgPath, err := path()
	if err != nil {
		return nil, err
	}

	fi, err := os.Open(cfgPath)
	if err != nil {
		if !errors.Is(err, fs.ErrNotExist) {
			return nil, err
		}
		fi, err = os.Create(cfgPath)
		if err != nil {
			return nil, err
		}
		if _, err := fi.WriteString("{}"); err != nil {
			return nil, err
		}
		if _, err := fi.Seek(0, 0); err != nil {
			return nil, err
		}
	}
	defer fi.Close()

	var cfg Config
	return &cfg, json.NewDecoder(fi).Decode(&cfg)
}

func Save(c Config) error {
	cfgPath, err := path()
	if err != nil {
		return err
	}

	fi, err := os.Create(cfgPath)
	if err != nil {
		return err
	}
	defer fi.Close()
	return json.NewEncoder(fi).Encode(c)
}