package controller

import (
	"fmt"
	"net/http"
	"strconv"
	"time"

	"ezops/model"

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

// UnifiedAlertItem 统一告警事件视图 // Logan.Li
type UnifiedAlertItem struct {
	ID          string  `json:"id"`
	SourceType  string  `json:"source_type"`
	RuleName    string  `json:"rule_name"`
	Title       string  `json:"title"`
	Message     string  `json:"message"`
	Severity    string  `json:"severity"`
	Status      string  `json:"status"`
	Target      string  `json:"target"`
	Metric      string  `json:"metric"`
	Value       float64 `json:"value"`
	Threshold   float64 `json:"threshold"`
	StartedAt   string  `json:"started_at"`
	ResolvedAt  *string `json:"resolved_at,omitempty"`
}

// ListUnifiedAlerts 统一告警列表（主机 + 中间件 + 站点 + 日志）
// GET /api/v1/alerts/unified
func (h *AlertHandler) ListUnifiedAlerts(c *gin.Context) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	if pageSize > 100 {
		pageSize = 100
	}
	statusFilter := c.Query("status")
	severityFilter := c.Query("severity")
	sourceFilter := c.Query("source_type")

	items := make([]UnifiedAlertItem, 0)

	// 1. Agent 主机/中间件/SNMP 告警（中间件与 SNMP 复用 AgentAlert 存储）
	if sourceFilter == "" || sourceFilter == "host" || sourceFilter == "middleware" || sourceFilter == "snmp" {
		var alerts []model.AgentAlert
		q := h.db.Model(&model.AgentAlert{}).Order("created_at DESC").Limit(200)
		if statusFilter == "firing" || statusFilter == "" {
			if statusFilter == "firing" {
				q = q.Where("resolved = ?", false)
			}
		} else if statusFilter == "resolved" {
			q = q.Where("resolved = ?", true)
		}
		if severityFilter != "" {
			q = q.Where("severity = ?", severityFilter)
		}
		q.Find(&alerts)
		for _, a := range alerts {
			st := "firing"
			if a.Resolved {
				st = "resolved"
			}
			srcType := "host"
			if isSNMPMetric(a.Metric) {
				srcType = "snmp"
			} else if isMiddlewareMetric(a.Metric) {
				srcType = "middleware"
			}
			if sourceFilter == "host" && srcType != "host" {
				continue
			}
			if sourceFilter == "middleware" && srcType != "middleware" {
				continue
			}
			if sourceFilter == "snmp" && srcType != "snmp" {
				continue
			}
			var resolved *string
			if a.ResolvedAt != nil {
				s := a.ResolvedAt.Format(time.RFC3339)
				resolved = &s
			}
			items = append(items, UnifiedAlertItem{
				ID: "agent-" + strconv.Itoa(int(a.ID)), SourceType: srcType,
				RuleName: a.RuleName, Title: a.RuleName, Message: a.Message,
				Severity: a.Severity, Status: st, Target: a.Hostname,
				Metric: a.Metric, Value: a.Value, Threshold: a.Threshold,
				StartedAt: a.CreatedAt.Format(time.RFC3339), ResolvedAt: resolved,
			})
		}
	}

	// 2. 站点拨测告警
	if sourceFilter == "" || sourceFilter == "site" {
		var alerts []model.SiteAlert
		q := h.db.Model(&model.SiteAlert{}).Preload("Task").Order("started_at DESC").Limit(200)
		if statusFilter == "firing" {
			q = q.Where("status = ?", model.SiteAlertStatusActive)
		} else if statusFilter == "resolved" {
			q = q.Where("status = ?", model.SiteAlertStatusResolved)
		}
		if severityFilter != "" {
			q = q.Where("severity = ?", severityFilter)
		}
		q.Find(&alerts)
		for _, a := range alerts {
			st := "firing"
			if a.Status == model.SiteAlertStatusResolved {
				st = "resolved"
			}
			target := fmt.Sprintf("task-%d", a.TaskID)
			if a.Task != nil {
				target = a.Task.Name
			}
			var resolved *string
			if a.ResolvedAt != nil {
				s := a.ResolvedAt.Format(time.RFC3339)
				resolved = &s
			}
			items = append(items, UnifiedAlertItem{
				ID: "site-" + strconv.Itoa(int(a.ID)), SourceType: "site",
				RuleName: a.Title, Title: a.Title, Message: a.Message,
				Severity: string(a.Severity), Status: st, Target: target,
				Metric: a.TriggerType, Value: a.ResponseTime, Threshold: a.Threshold,
				StartedAt: a.StartedAt.Format(time.RFC3339), ResolvedAt: resolved,
			})
		}
	}

	// 3. 日志/通用 AlertEvent
	if sourceFilter == "" || sourceFilter == "log" {
		var events []model.AlertEvent
		q := h.db.Model(&model.AlertEvent{}).Order("started_at DESC").Limit(200)
		if statusFilter != "" && statusFilter != "all" {
			q = q.Where("status = ?", statusFilter)
		}
		if severityFilter != "" {
			q = q.Where("severity = ?", severityFilter)
		}
		q.Find(&events)
		for _, e := range events {
			var resolved *string
			if e.ResolvedAt != nil {
				s := e.ResolvedAt.Format(time.RFC3339)
				resolved = &s
			}
			items = append(items, UnifiedAlertItem{
				ID: "event-" + strconv.Itoa(int(e.ID)), SourceType: "log",
				RuleName: e.RuleName, Title: e.RuleName, Message: e.Message,
				Severity: e.Severity, Status: e.Status, Target: e.Target,
				Metric: "log", Value: e.Value, Threshold: e.Threshold,
				StartedAt: e.StartedAt.Format(time.RFC3339), ResolvedAt: resolved,
			})
		}
	}

	// 按时间排序
	sortUnifiedAlerts(items)

	total := len(items)
	start := (page - 1) * pageSize
	if start > total {
		start = total
	}
	end := start + pageSize
	if end > total {
		end = total
	}
	pageItems := items[start:end]

	// 统计
	stats := gin.H{
		"firing":   countStatus(items, "firing"),
		"critical": countSeverityStatus(items, "critical", "firing"),
		"warning":  countSeverityStatus(items, "warning", "firing"),
		"resolved": countStatus(items, "resolved"),
	}

	c.JSON(http.StatusOK, model.Response{
		Code: 200,
		Data: gin.H{"list": pageItems, "total": total, "stats": stats},
	})
}

func sortUnifiedAlerts(items []UnifiedAlertItem) {
	for i := 0; i < len(items); i++ {
		for j := i + 1; j < len(items); j++ {
			if items[j].StartedAt > items[i].StartedAt {
				items[i], items[j] = items[j], items[i]
			}
		}
	}
}

func countStatus(items []UnifiedAlertItem, status string) int {
	n := 0
	for _, it := range items {
		if it.Status == status {
			n++
		}
	}
	return n
}

func countSeverityStatus(items []UnifiedAlertItem, sev, status string) int {
	n := 0
	for _, it := range items {
		if it.Severity == sev && it.Status == status {
			n++
		}
	}
	return n
}