package main

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

const (
	dshPackage   = "@deepseek-ai/dsh"
	allowScripts = "@deepseek-ai/dsh-subprocess-local,koffi,node-pty,@google/genai,protobufjs"
)

// npmGlobalRoot 执行 npm root -g（隐藏窗口），返回全局 node_modules 路径。
func npmGlobalRoot() string {
	exe, args := npmCommandFor("root", "-g")
	cmd := exec.Command(exe, args...)
	hideWindow(cmd)
	out, err := cmd.Output()
	if err != nil {
		return ""
	}
	return strings.TrimSpace(string(out))
}

// npmCommandFor 组装 npm 调用：优先 node + npm-cli.js，回退 cmd /c npm。
func npmCommandFor(args ...string) (string, []string) {
	if node, err := exec.LookPath("node"); err == nil {
		if cli := detectNpmCLI(node); cli != "" {
			return node, append([]string{cli}, args...)
		}
	}
	return "cmd.exe", append([]string{"/c", "npm"}, args...)
}

func detectNpmCLI(node string) string {
	base := filepath.Dir(node)
	candidates := []string{
		filepath.Join(base, "node_modules", "npm", "bin", "npm-cli.js"),
		filepath.Join(base, "..", "lib", "node_modules", "npm", "bin", "npm-cli.js"),
	}
	for _, c := range candidates {
		if fileExists(c) {
			return c
		}
	}
	return ""
}

// readPackageVersion 读取 package.json 的 version。
func readPackageVersion(path string) string {
	data, err := os.ReadFile(path)
	if err != nil {
		return ""
	}
	var v struct {
		Version string `json:"version"`
	}
	if err := json.Unmarshal(data, &v); err != nil {
		return ""
	}
	return v.Version
}

// Update 执行全局更新：npm install -g @deepseek-ai/dsh@latest --allow-scripts=...
func (s *Supervisor) Update() (string, error) {
	s.mu.Lock()
	if s.updating {
		s.mu.Unlock()
		return "", errors.New("更新已在进行中")
	}
	s.updating = true
	s.mu.Unlock()
	defer func() {
		s.mu.Lock()
		s.updating = false
		s.mu.Unlock()
	}()

	exe, args := npmCommandFor("install", "-g", dshPackage+"@latest", "--allow-scripts="+allowScripts)
	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
	defer cancel()
	cmd := exec.CommandContext(ctx, exe, args...)
	hideWindow(cmd)
	s.log.Printf("执行更新: %s %s", exe, strings.Join(args, " "))
	out, err := cmd.CombinedOutput()
	text := strings.TrimSpace(string(out))
	if text != "" {
		s.log.Printf("更新输出: %s", text)
	}
	if err != nil {
		return text, fmt.Errorf("更新失败: %w", err)
	}
	s.mu.Lock()
	s.binCache = ""
	s.mu.Unlock()
	return text, nil
}

// LatestVersion 查询 npm 上最新版本。
func (s *Supervisor) LatestVersion() (string, error) {
	exe, args := npmCommandFor("view", dshPackage, "version")
	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
	defer cancel()
	cmd := exec.CommandContext(ctx, exe, args...)
	hideWindow(cmd)
	out, err := cmd.Output()
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(out)), nil
}

// startAutoUpdate 定期后台更新：按间隔轮询，发现新版本才更新并重启。
func (s *Supervisor) startAutoUpdate() {
	go func() {
		for {
			s.mu.Lock()
			enabled := s.cfg.AutoUpdate
			hours := s.cfg.UpdateIntervalH
			s.mu.Unlock()
			if !enabled {
				s.log.Printf("定期更新：已关闭")
				return
			}
			if hours <= 0 {
				hours = 24
			}
			time.Sleep(time.Duration(hours) * time.Hour)

			s.mu.Lock()
			enabled = s.cfg.AutoUpdate
			s.mu.Unlock()
			if !enabled {
				return
			}

			latest, err := s.LatestVersion()
			if err != nil {
				s.log.Printf("定期更新：查询最新版本失败: %v", err)
				continue
			}
			current := s.installedVersion()
			if latest == "" || current == latest {
				s.log.Printf("定期更新：已是最新（%s）", current)
				continue
			}
			s.log.Printf("定期更新：发现新版本 %s（当前 %s），开始更新", latest, current)
			if _, err := s.Update(); err != nil {
				s.log.Printf("定期更新失败: %v", err)
				continue
			}
			s.Restart()
		}
	}()
}