package config

import (
	"fmt"
	"os"
	"path/filepath"
)

// EnvConfigPath is the env var that, when set, overrides XDG lookup entirely.
const EnvConfigPath = "CC_SWITCH_CONFIG"

// ResolvePath returns the path cc-switch reads/writes. Precedence:
//  1. CC_SWITCH_CONFIG  (full path, used as-is)
//  2. $XDG_CONFIG_HOME/cc-switch/config.yaml
//  3. ~/.config/cc-switch/config.yaml
//
// The --config flag, when provided, bypasses this function entirely.
func ResolvePath() (string, error) {
	if v := os.Getenv(EnvConfigPath); v != "" {
		return ExpandUser(v)
	}
	if xdg := os.Getenv("XDG_CONFIG_HOME"); xdg != "" {
		return filepath.Join(xdg, "cc-switch", "config.yaml"), nil
	}
	home, err := os.UserHomeDir()
	if err != nil {
		return "", fmt.Errorf("resolve home dir: %w", err)
	}
	return filepath.Join(home, ".config", "cc-switch", "config.yaml"), nil
}