package controller

import (
	"bytes"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"strings"
	"time"

	"ezops/model"

	"github.com/gin-gonic/gin"
)

// 通知渠道 CRUD（AlertHandler 方法接收者，与 alert.go 同包共享） // Logan.Li

// ListNotifyChannels 获取通知渠道列表 // Logan.Li
// @Summary 获取通知渠道列表
// @Description 获取所有通知渠道列表
// @Tags 告警
// @Produce json
// @Security Bearer
// @Success 200 {object} model.Response{data=model.ListResponse}
// @Router /alerts/notify-channels [get]
func (h *AlertHandler) ListNotifyChannels(c *gin.Context) {
	var channels []model.NotifyChannel
	h.db.Order("created_at DESC").Find(&channels)

	c.JSON(http.StatusOK, model.Response{
		Code:    200,
		Message: "success",
		Data: model.ListResponse{
			List:  channels,
			Total: int64(len(channels)),
		},
	})
}

// CreateNotifyChannel 创建通知渠道 // Logan.Li
// @Summary 创建通知渠道
// @Description 创建新通知渠道
// @Tags 告警
// @Accept json
// @Produce json
// @Security Bearer
// @Param request body model.CreateNotifyChannelRequest true "创建请求"
// @Success 200 {object} model.Response{data=model.NotifyChannel}
// @Router /alerts/notify-channels [post]
func (h *AlertHandler) CreateNotifyChannel(c *gin.Context) {
	var req model.CreateNotifyChannelRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	channel := model.NotifyChannel{
		Name:    req.Name,
		Type:    req.Type,
		Config:  req.Config,
		Enabled: true,
	}

	if err := h.db.Create(&channel).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{
			Code:    500,
			Message: "创建失败",
		})
		return
	}

	c.JSON(http.StatusOK, model.Response{
		Code:    200,
		Message: "创建成功",
		Data:    channel,
	})
}

// UpdateNotifyChannel 更新通知渠道 // Logan.Li
// @Summary 更新通知渠道
// @Description 更新指定通知渠道
// @Tags 告警
// @Accept json
// @Produce json
// @Security Bearer
// @Param id path int true "渠道ID"
// @Param request body model.UpdateNotifyChannelRequest true "更新请求"
// @Success 200 {object} model.Response{data=model.NotifyChannel}
// @Router /alerts/notify-channels/{id} [put]
func (h *AlertHandler) UpdateNotifyChannel(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var req model.UpdateNotifyChannelRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	var channel model.NotifyChannel
	if err := h.db.First(&channel, id).Error; err != nil {
		c.JSON(http.StatusNotFound, model.Response{
			Code:    404,
			Message: "通知渠道不存在",
		})
		return
	}

	updates := map[string]interface{}{}
	if req.Name != "" {
		updates["name"] = req.Name
	}
	if req.Type != "" {
		updates["type"] = req.Type
	}
	if req.Config != "" {
		updates["config"] = req.Config
	}
	if req.Enabled != nil {
		updates["enabled"] = *req.Enabled
	}

	if err := h.db.Model(&channel).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{
			Code:    500,
			Message: "更新失败",
		})
		return
	}

	h.db.First(&channel, id)
	c.JSON(http.StatusOK, model.Response{
		Code:    200,
		Message: "更新成功",
		Data:    channel,
	})
}

// DeleteNotifyChannel 删除通知渠道 // Logan.Li
// @Summary 删除通知渠道
// @Description 删除指定通知渠道
// @Tags 告警
// @Produce json
// @Security Bearer
// @Param id path int true "渠道ID"
// @Success 200 {object} model.Response
// @Router /alerts/notify-channels/{id} [delete]
func (h *AlertHandler) DeleteNotifyChannel(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	if err := h.db.Delete(&model.NotifyChannel{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, model.Response{
			Code:    500,
			Message: "删除失败",
		})
		return
	}

	c.JSON(http.StatusOK, model.Response{
		Code:    200,
		Message: "删除成功",
	})
}

// TestNotifyChannel 测试通知渠道 — 真实发送测试消息 // Logan.Li
// @Summary 测试通知渠道连通性
// @Description 向渠道发送测试消息，验证连通性
// @Tags 告警
// @Produce json
// @Security Bearer
// @Param id path int true "渠道ID"
// @Success 200 {object} model.Response
// @Router /alerts/notify-channels/{id}/test [post]
func (h *AlertHandler) TestNotifyChannel(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var channel model.NotifyChannel
	if err := h.db.First(&channel, id).Error; err != nil {
		c.JSON(http.StatusNotFound, model.Response{
			Code:    404,
			Message: "通知渠道不存在",
		})
		return
	}

	status := "success"
	message := "测试通知已发送"

	switch channel.Type {
	case "feishu":
		err := sendFeishuTest(channel.Config)
		if err != nil {
			status = "error"
			message = "飞书通知发送失败: " + err.Error()
		}
	default:
		// 非飞书渠道仅检查配置非空
		if channel.Config == "" {
			status = "warning"
			message = "渠道未配置参数，请先完善配置"
		}
	}

	h.db.Model(&channel).Update("test_status", status)

	c.JSON(http.StatusOK, model.Response{
		Code:    200,
		Message: message,
		Data: gin.H{
			"status":  status,
			"channel": channel.Name,
			"type":    channel.Type,
		},
	})
}

// ==================== 飞书 Webhook 发送逻辑 ====================

// sendFeishuTest 发送飞书测试通知
func sendFeishuTest(configJSON string) error {
	var cfg model.FeishuWebhookConfig
	if err := json.Unmarshal([]byte(configJSON), &cfg); err != nil {
		return fmt.Errorf("解析配置失败: %w", err)
	}
	if cfg.URL == "" {
		return fmt.Errorf("webhook URL 为空")
	}

	title := "✅ AIOps 告警测试通知"
	content := fmt.Sprintf("**测试时间**：%s\\n**来源**：AIOps 智能运维平台\\n**状态**：连通性测试成功 🎉", time.Now().Format("2006-01-02 15:04:05"))

	return sendFeishuCard(cfg.URL, cfg.Secret, title, content, "green")
}

// sendFeishuAlert 发送飞书告警通知
func sendFeishuAlert(configJSON, title, content, severity string) error {
	var cfg model.FeishuWebhookConfig
	if err := json.Unmarshal([]byte(configJSON), &cfg); err != nil {
		return fmt.Errorf("解析配置失败: %w", err)
	}
	if cfg.URL == "" {
		return fmt.Errorf("webhook URL 为空")
	}

	color := "red"
	if severity == "warning" {
		color = "orange"
	} else if severity == "info" {
		color = "blue"
	}

	emoji := "🔴"
	if severity == "warning" {
		emoji = "🟠"
	} else if severity == "info" {
		emoji = "🔵"
	}

	title = emoji + " " + title
	return sendFeishuCard(cfg.URL, cfg.Secret, title, content, color)
}

// sendFeishuRecovery 发送飞书恢复通知
func sendFeishuRecovery(configJSON, title, content string) error {
	var cfg model.FeishuWebhookConfig
	if err := json.Unmarshal([]byte(configJSON), &cfg); err != nil {
		return fmt.Errorf("解析配置失败: %w", err)
	}
	if cfg.URL == "" {
		return fmt.Errorf("webhook URL 为空")
	}

	title = "✅ " + title
	return sendFeishuCard(cfg.URL, cfg.Secret, title, content, "green")
}

// sendFeishuCard 发送飞书交互卡片消息
func sendFeishuCard(webhookURL, secret, title, content, color string) error {
	// 解析 content 中的字段（格式: 多行 key: value）
	lines := splitLines(content)
	var fields []map[string]interface{}
	for _, line := range lines {
		line = strings.TrimSpace(line)
		if line == "" {
			continue
		}
		fields = append(fields, map[string]interface{}{
			"is_short": false,
			"text": map[string]interface{}{
				"tag":     "lark_md",
				"content": line,
			},
		})
	}

	template := color
	if template == "red" {
		template = "red"
	} else if template == "orange" || template == "warning" {
		template = "orange"
	} else if template == "green" {
		template = "green"
	} else if template == "blue" || template == "info" {
		template = "blue"
	} else {
		template = "red"
	}

	card := map[string]interface{}{
		"msg_type": "interactive",
		"card": map[string]interface{}{
			"header": map[string]interface{}{
				"title": map[string]interface{}{
					"tag":     "plain_text",
					"content": title,
				},
				"template": template,
			},
			"elements": []map[string]interface{}{
				{
					"tag":    "div",
					"fields": fields,
				},
				{
					"tag": "hr",
				},
				{
					"tag": "note",
					"elements": []map[string]interface{}{
						{
							"tag":     "plain_text",
							"content": fmt.Sprintf("⏰ %s ｜ AIOps 智能运维平台", time.Now().Format("2006-01-02 15:04:05")),
						},
					},
				},
			},
		},
	}

	body, _ := json.Marshal(card)

	req, err := http.NewRequest("POST", webhookURL, bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("创建请求失败: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")

	// 如果有 secret，追加签名到 URL query
	if secret != "" {
		timestamp := time.Now().Unix()
		sign := genFeishuSign(timestamp, secret)
		q := req.URL.Query()
		q.Set("timestamp", fmt.Sprintf("%d", timestamp))
		q.Set("sign", sign)
		req.URL.RawQuery = q.Encode()
	}

	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("发送请求失败: %w", err)
	}
	defer resp.Body.Close()

	respBody, _ := io.ReadAll(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("飞书返回错误 (HTTP %d): %s", resp.StatusCode, string(respBody))
	}

	var result struct {
		Code int    `json:"code"`
		Msg  string `json:"msg"`
	}
	json.Unmarshal(respBody, &result)
	if result.Code != 0 {
		return fmt.Errorf("飞书返回错误 (code=%d): %s", result.Code, result.Msg)
	}

	return nil
}

// splitLines splits a string by newlines, handling both actual \n and escaped \\n
func splitLines(s string) []string {
	// First replace literal \n (from Go format strings) with actual newlines
	s = strings.ReplaceAll(s, "\\n", "\n")
	return strings.Split(s, "\n")
}

// buildFeishuCard 构建飞书卡片消息体（保留备用，当前使用文本格式）
func buildFeishuCard(title, content, color string) model.FeishuCardMessage {
	return model.FeishuCardMessage{
		MsgType: "interactive",
		Content: model.FeishuCardContent{
			Title: title,
			Content: [][]model.FeishuCardElement{
				{
					{
						Tag:  "markdown",
						Text: content,
					},
				},
				{
					{
						Tag:  "note",
						Text: fmt.Sprintf("⏰ %s ｜ AIOps 智能运维平台", time.Now().Format("2006-01-02 15:04:05")),
					},
				},
			},
		},
	}
}

// genFeishuSign 生成飞书签名
func genFeishuSign(timestamp int64, secret string) string {
	stringToSign := fmt.Sprintf("%d\n%s", timestamp, secret)
	h := hmac.New(sha256.New, []byte(stringToSign))
	signature := base64.StdEncoding.EncodeToString(h.Sum(nil))
	return signature
}

// ==================== 批量通知发送 ====================

// NotifyAlert 发送告警通知到所有启用的渠道
func (h *AlertHandler) NotifyAlert(ruleName, hostname, metric, severity, message string, value, threshold float64) {
	var channels []model.NotifyChannel
	h.db.Where("enabled = ?", true).Find(&channels)

	for _, ch := range channels {
		switch ch.Type {
		case "feishu":
			title := buildAlertTitle(ruleName, hostname, metric, severity)
			content := buildAlertContent(ruleName, hostname, metric, severity, message, value, threshold)
			if err := sendFeishuAlert(ch.Config, title, content, severity); err != nil {
				fmt.Printf("[AlertNotify] 飞书通知失败 (渠道:%s): %v\n", ch.Name, err)
			}
		}
	}
}

// NotifyRecovery 发送恢复通知到所有启用的渠道
func (h *AlertHandler) NotifyRecovery(ruleName, hostname, metric, message string) {
	var channels []model.NotifyChannel
	h.db.Where("enabled = ?", true).Find(&channels)

	for _, ch := range channels {
		switch ch.Type {
		case "feishu":
			title := fmt.Sprintf("%s — 已恢复正常", ruleName)
			content := fmt.Sprintf("**告警已恢复**\\n\\n主机：%s\\n指标：%s\\n详情：%s\\n恢复时间：%s",
				hostname, metric, message, time.Now().Format("2006-01-02 15:04:05"))
			if err := sendFeishuRecovery(ch.Config, title, content); err != nil {
				fmt.Printf("[AlertNotify] 飞书恢复通知失败 (渠道:%s): %v\n", ch.Name, err)
			}
		}
	}
}

func buildAlertTitle(ruleName, hostname, metric, severity string) string {
	sevLabel := "严重告警"
	if severity == "warning" {
		sevLabel = "警告"
	} else if severity == "info" {
		sevLabel = "信息"
	}
	return fmt.Sprintf("[%s] %s — %s (%s)", sevLabel, ruleName, hostname, metric)
}

func buildAlertContent(ruleName, hostname, metric, severity, message string, value, threshold float64) string {
	return fmt.Sprintf(
		"**规则名称：** %s\\n**目标主机：** %s\\n**指标类型：** %s\\n**告警级别：** %s\\n**当前值：** %.2f\\n**阈值：** %.2f\\n**详细信息：** %s\\n**触发时间：** %s",
		ruleName, hostname, metric, severity, value, threshold, message, time.Now().Format("2006-01-02 15:04:05"),
	)
}