package config

import (
	"bufio"
	"os"
	"path/filepath"
	"strings"
)

// LoadDotEnv reads KEY=VALUE lines from path if the file exists.
// Variables already set in the environment are not overwritten.
func LoadDotEnv(path string) {
	f, err := os.Open(path)
	if err != nil {
		return
	}
	defer f.Close()

	sc := bufio.NewScanner(f)
	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		key, val, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}
		key = strings.TrimSpace(key)
		val = strings.TrimSpace(val)
		if key == "" {
			continue
		}
		if _, exists := os.LookupEnv(key); exists {
			continue
		}
		_ = os.Setenv(key, val)
	}
}

func loadEnvFiles() {
	seen := make(map[string]struct{})
	try := func(path string) {
		if path == "" {
			return
		}
		if _, ok := seen[path]; ok {
			return
		}
		seen[path] = struct{}{}
		LoadDotEnv(path)
	}

	try(".env")

	if exe, err := os.Executable(); err == nil {
		try(filepath.Join(filepath.Dir(exe), ".env"))
		try(filepath.Join(filepath.Dir(exe), "..", ".env"))
	}
}