package main

import (
	"bufio"
	"crypto/rand"
	"fmt"
	"os"
	"strconv"
	"strings"
)

type agentCfg struct {
	BailianBaseURL    string
	BailianWssBaseURL string
	BailianKey        string
	TTSModel          string
	TTSVoice          string
	TTSInstruction    string
	VoiceAPIURL       string
	LLMModel          string
	VolcAppKey        string // 新版控制台：单凭证
	VolcAppID         string // 旧版控制台：APP ID + Access Token 两件套
	VolcAccessToken   string
	VolcResourceID    string
}

// loadDotEnv 加载简单的 KEY=VALUE / export KEY=VALUE；系统环境变量优先。
func loadDotEnv(path string) error {
	f, err := os.Open(path)
	if os.IsNotExist(err) {
		return nil
	}
	if err != nil {
		return err
	}
	defer f.Close()

	scanner := bufio.NewScanner(f)
	for lineNo := 1; scanner.Scan(); lineNo++ {
		line := strings.TrimSpace(strings.TrimPrefix(scanner.Text(), "\ufeff"))
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		line = strings.TrimSpace(strings.TrimPrefix(line, "export "))
		key, value, ok := strings.Cut(line, "=")
		key, value = strings.TrimSpace(key), strings.TrimSpace(value)
		if !ok || key == "" {
			return fmt.Errorf("%s:%d: 无效的 dotenv 配置", path, lineNo)
		}
		if len(value) >= 2 && value[0] == value[len(value)-1] {
			switch value[0] {
			case '\'':
				value = value[1 : len(value)-1]
			case '"':
				value, err = strconv.Unquote(value)
				if err != nil {
					return fmt.Errorf("%s:%d: %w", path, lineNo, err)
				}
			}
		}
		if _, exists := os.LookupEnv(key); !exists {
			if err := os.Setenv(key, value); err != nil {
				return fmt.Errorf("%s:%d: %w", path, lineNo, err)
			}
		}
	}
	return scanner.Err()
}

func loadCfg() agentCfg {
	return agentCfg{
		BailianBaseURL:    getenv("BAILIAN_BASE_URL", ""),
		BailianWssBaseURL: getenv("BAILIAN_WSS_BASE_URL", ""),
		BailianKey:        getenv("BAILIAN_API_KEY", ""),
		TTSModel:          getenv("BAILIAN_TTS_MODEL", "cosyvoice-v3.5-plus"),
		TTSVoice:          getenv("BAILIAN_TTS_VOICE", ""),
		TTSInstruction:    getenv("BAILIAN_TTS_INSTRUCTION", ""),
		VoiceAPIURL:       getenv("BAILIAN_VOICE_API_URL", "https://dashscope.aliyuncs.com/api/v1/services/audio/tts/customization"),
		LLMModel:          getenv("BAILIAN_LLM_MODEL", "qwen3.8-flash"),
		VolcAppKey:        getenv("VOLC_ASR_APP_KEY", ""),
		VolcAppID:         getenv("VOLC_ASR_APP_ID", ""),
		VolcAccessToken:   getenv("VOLC_ASR_ACCESS_TOKEN", ""),
		VolcResourceID:    getenv("VOLC_ASR_RESOURCE_ID", "volc.bigasr.sauc.duration"),
	}
}

func getenv(k, def string) string {
	if v := os.Getenv(k); v != "" {
		return v
	}
	return def
}

func uuid() string {
	var b [16]byte
	rand.Read(b[:])
	b[6] = (b[6] & 0x0f) | 0x40
	b[8] = (b[8] & 0x3f) | 0x80
	return fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
}