package cfdav

import (
	"encoding/base64"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"

	"ops-assistant/internal/core/command"
	"ops-assistant/internal/core/ecode"
	"ops-assistant/models"

	"gorm.io/gorm"
)

type Module struct {
	db *gorm.DB
}

type settings struct {
	APIBase   string
	AdminUser string
	AdminPass string
}

type userItem struct {
	ID        string `json:"id"`
	Email     string `json:"email"`
	IsAdmin   int    `json:"is_admin"`
	CreatedAt string `json:"created_at"`
}

type listResp struct {
	Success bool       `json:"success"`
	Data    []userItem `json:"data"`
	Error   string     `json:"error"`
}

type simpleResp struct {
	Success bool   `json:"success"`
	Error   string `json:"error"`
}

func New(db *gorm.DB) *Module {
	return &Module{db: db}
}

func (m *Module) Handle(userID int64, cmd *command.ParsedCommand) (string, error) {
	text := strings.TrimSpace(cmd.Raw)
	if text == "/cfdav" || strings.HasPrefix(text, "/cfdav help") {
		return "cfdav 模块\n- /cfdav users\n- /cfdav add <email> <password> [admin]\n- /cfdav del <user_id>", nil
	}

	parts := strings.Fields(text)
	if len(parts) == 0 {
		return ecode.Tag(ecode.ErrStepFailed, "空命令"), nil
	}
	// 支持别名：/cfdav list
	if len(parts) >= 2 && (parts[1] == "users" || parts[1] == "list") {
		return m.listUsers()
	}
	if len(parts) >= 2 && (parts[1] == "add" || (len(parts) >= 3 && parts[1] == "user" && parts[2] == "add")) {
		return m.addUser(parts)
	}
	if len(parts) >= 2 && (parts[1] == "del" || parts[1] == "delete" || (len(parts) >= 3 && parts[1] == "user" && (parts[2] == "del" || parts[2] == "delete"))) {
		return m.deleteUser(parts)
	}
	return ecode.Tag(ecode.ErrStepFailed, "cfdav 模块已接入，当前支持：/cfdav users, /cfdav add, /cfdav del"), nil
}

func (m *Module) listUsers() (string, error) {
	cfg, err := m.loadSettings()
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	url := strings.TrimRight(cfg.APIBase, "/") + "/api/admin/users"
	resp, status, err := m.doRequest(http.MethodGet, url, nil, cfg)
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	if status >= 400 {
		return ecode.Tag(ecode.ErrStepFailed, fmt.Sprintf("upstream http %d: %s", status, resp)), nil
	}
	var out listResp
	if err := json.Unmarshal([]byte(resp), &out); err != nil {
		return ecode.Tag(ecode.ErrStepFailed, "响应解析失败"), nil
	}
	if !out.Success {
		return ecode.Tag(ecode.ErrStepFailed, out.Error), nil
	}
	if len(out.Data) == 0 {
		return "📭 cfdav 用户列表为空", nil
	}
	limit := len(out.Data)
	if limit > 50 {
		limit = 50
	}
	lines := make([]string, 0, limit+2)
	lines = append(lines, fmt.Sprintf("✅ cfdav 用户列表（%d）", len(out.Data)))
	for i := 0; i < limit; i++ {
		u := out.Data[i]
		admin := "user"
		if u.IsAdmin == 1 {
			admin = "admin"
		}
		lines = append(lines, fmt.Sprintf("- %s | %s | %s", u.ID, u.Email, admin))
	}
	if len(out.Data) > limit {
		lines = append(lines, fmt.Sprintf("... 共 %d 个，已展示前 %d 个", len(out.Data), limit))
	}
	return strings.Join(lines, "\n"), nil
}

func (m *Module) addUser(parts []string) (string, error) {
	cfg, err := m.loadSettings()
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	// 支持: /cfdav add <email> <pass> [admin]
	// 或: /cfdav user add <email> <pass> [admin]
	idx := 2
	if len(parts) >= 3 && parts[1] == "user" {
		idx = 3
	}
	if len(parts) < idx+2 {
		return ecode.Tag(ecode.ErrStepFailed, "缺少参数，示例：/cfdav add <email> <password> [admin]"), nil
	}
	email := strings.TrimSpace(parts[idx])
	pass := strings.TrimSpace(parts[idx+1])
	if email == "" || pass == "" {
		return ecode.Tag(ecode.ErrStepFailed, "email/password 不能为空"), nil
	}
	isAdmin := false
	if len(parts) >= idx+3 {
		flag := strings.ToLower(strings.TrimSpace(parts[idx+2]))
		isAdmin = flag == "admin" || flag == "1" || flag == "true" || flag == "yes"
	}
	payload := map[string]any{"email": email, "password": pass, "isAdmin": isAdmin}
	body, _ := json.Marshal(payload)
	url := strings.TrimRight(cfg.APIBase, "/") + "/api/admin/users"
	resp, status, err := m.doRequest(http.MethodPost, url, body, cfg)
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	if status >= 400 {
		return ecode.Tag(ecode.ErrStepFailed, fmt.Sprintf("upstream http %d: %s", status, resp)), nil
	}
	var out simpleResp
	if err := json.Unmarshal([]byte(resp), &out); err != nil {
		return ecode.Tag(ecode.ErrStepFailed, "响应解析失败"), nil
	}
	if !out.Success {
		return ecode.Tag(ecode.ErrStepFailed, out.Error), nil
	}
	return fmt.Sprintf("✅ cfdav 用户已创建：%s", email), nil
}

func (m *Module) deleteUser(parts []string) (string, error) {
	cfg, err := m.loadSettings()
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	// 支持: /cfdav del <id> 或 /cfdav user del <id>
	idx := 2
	if len(parts) >= 3 && parts[1] == "user" {
		idx = 3
	}
	if len(parts) < idx+1 {
		return ecode.Tag(ecode.ErrStepFailed, "缺少参数，示例：/cfdav del <user_id>"), nil
	}
	id := strings.TrimSpace(parts[idx])
	if id == "" {
		return ecode.Tag(ecode.ErrStepFailed, "user_id 不能为空"), nil
	}
	url := strings.TrimRight(cfg.APIBase, "/") + "/api/admin/users/" + id
	resp, status, err := m.doRequest(http.MethodDelete, url, nil, cfg)
	if err != nil {
		return ecode.Tag(ecode.ErrStepFailed, err.Error()), nil
	}
	if status >= 400 {
		return ecode.Tag(ecode.ErrStepFailed, fmt.Sprintf("upstream http %d: %s", status, resp)), nil
	}
	var out simpleResp
	if err := json.Unmarshal([]byte(resp), &out); err != nil {
		return ecode.Tag(ecode.ErrStepFailed, "响应解析失败"), nil
	}
	if !out.Success {
		return ecode.Tag(ecode.ErrStepFailed, out.Error), nil
	}
	return fmt.Sprintf("✅ cfdav 用户已删除：%s", id), nil
}

func (m *Module) loadSettings() (*settings, error) {
	if m.db == nil {
		return nil, errors.New("db 未初始化")
	}
	keys := []string{"cfdav_api_base", "cfdav_admin_user", "cfdav_admin_pass"}
	cfg := &settings{}
	for _, k := range keys {
		var sset models.AppSetting
		val := ""
		if err := m.db.Where("key = ?", k).First(&sset).Error; err == nil {
			val = sset.Value
		}
		switch k {
		case "cfdav_api_base":
			cfg.APIBase = strings.TrimSpace(val)
		case "cfdav_admin_user":
			cfg.AdminUser = strings.TrimSpace(val)
		case "cfdav_admin_pass":
			cfg.AdminPass = val
		}
	}
	if cfg.APIBase == "" {
		return nil, errors.New("cfdav api_base 未配置")
	}
	if cfg.AdminUser == "" || cfg.AdminPass == "" {
		return nil, errors.New("cfdav admin 账号未配置")
	}
	return cfg, nil
}

func (m *Module) doRequest(method, url string, body []byte, cfg *settings) (string, int, error) {
	var reader io.Reader
	if body != nil {
		reader = strings.NewReader(string(body))
	}
	req, err := http.NewRequest(method, url, reader)
	if err != nil {
		return "", 0, err
	}
	auth := cfg.AdminUser + ":" + cfg.AdminPass
	b64 := base64.StdEncoding.EncodeToString([]byte(auth))
	req.Header.Set("Authorization", "Basic "+b64)
	if body != nil {
		req.Header.Set("Content-Type", "application/json")
	}
	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return "", 0, err
	}
	defer resp.Body.Close()
	data, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", resp.StatusCode, err
	}
	return string(data), resp.StatusCode, nil
}