package controller

import (
	"context"
	"net/http"
	"strings"
	"sync"
	"time"

	"github.com/QuantumNous/new-api/common"
	"github.com/QuantumNous/new-api/model"
	perfmetrics "github.com/QuantumNous/new-api/pkg/perf_metrics"
	"github.com/QuantumNous/new-api/service"

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

const requestTimeout = 30 * time.Second

type Monitor struct {
	ProbeHistory    []service.ProbeHistoryPoint   `json:"probe_history"`
	ID              string                        `json:"id"`
	Models          []string                      `json:"models"`
	Alias           string                        `json:"alias,omitempty"`
	Hidden          bool                          `json:"hidden,omitempty"`
	Pelican         *service.PelicanSummary       `json:"pelican,omitempty"`
	StatusSource    string                        `json:"status_source"`
	StatusCheckedAt int64                         `json:"status_checked_at,omitempty"`
	Fingerprint     *service.AstraSamplingSummary `json:"fingerprint,omitempty"`
	Metrics         *perfmetrics.GroupResult      `json:"metrics,omitempty"`
	Name            string                        `json:"name"`
	Uptime          float64                       `json:"uptime"`
	Status          int                           `json:"status"`
	Group           string                        `json:"group,omitempty"`
	Ping            int                           `json:"ping,omitempty"`
	LastChecked     string                        `json:"last_checked,omitempty"`
	History         []MonitorSample               `json:"history,omitempty"`
	CacheStats      *model.GroupCacheStats        `json:"cache_stats,omitempty"`
	ProbeStatus     int                           `json:"probe_status"`
	ChannelDisabled bool                          `json:"channel_disabled"`
}

type MonitorSample struct {
	Status int    `json:"status"`
	Ping   int    `json:"ping,omitempty"`
	Time   string `json:"time"`
}

type UptimeGroupResult struct {
	CategoryName string    `json:"categoryName"`
	Monitors     []Monitor `json:"monitors"`
}

var groupCacheSnapshot struct {
	sync.Mutex
	updated  time.Time
	channels string
	stats    map[string]model.GroupCacheStats
	metrics  map[string]perfmetrics.GroupResult
}

const requestStatusFreshness = 2 * time.Hour

func currentGroupMonitors(ctx context.Context, admin bool) ([]UptimeGroupResult, error) {
	channels, err := model.GetStatusChannels(ctx)
	if err != nil {
		return nil, err
	}
	settings, err := model.GetStatusPageGroups(ctx)
	if err != nil {
		return nil, err
	}
	models, err := model.GetStatusPageModels(ctx, channels)
	if err != nil {
		return nil, err
	}
	usable := service.GetUserUsableGroups("")
	now := time.Now()
	fingerprints, fingerprintErr := service.AstraSamplingSummaries(ctx, now, settings)
	if fingerprintErr != nil {
		return nil, fingerprintErr
	}
	detections, detectionErr := service.GroupDetectionSummaries(ctx, now, fingerprints, settings)
	if detectionErr != nil {
		return nil, detectionErr
	}
	active := make(map[string]bool)
	order := make([]string, 0)
	for _, channel := range channels {
		for _, group := range strings.Split(channel.Group, ",") {
			group = strings.TrimSpace(group)
			if _, visible := usable[group]; (!visible || settings[group].Hidden) && !admin {
				continue
			}
			if _, exists := active[group]; !exists {
				order = append(order, group)
			}
			active[group] = active[group] || channel.Status == common.ChannelStatusEnabled
		}
	}
	encoded, err := common.Marshal(channels)
	if err != nil {
		return nil, err
	}
	groupCacheSnapshot.Lock()
	defer groupCacheSnapshot.Unlock()
	if time.Since(groupCacheSnapshot.updated) >= time.Minute || groupCacheSnapshot.channels != string(encoded) {
		now := time.Now()
		stats, statsErr := model.GetGroupCacheStats(ctx, channels, now.Add(-24*time.Hour), now)
		if statsErr != nil {
			return nil, statsErr
		}
		groupCacheSnapshot.stats = stats
		names := []string{}
		if err := model.DB.WithContext(ctx).Model(&model.Ability{}).Where("enabled = ?", true).Distinct().Pluck("model", &names).Error; err != nil {
			return nil, err
		}
		performance, metricsErr := perfmetrics.QueryGroups(names, 24)
		if metricsErr != nil {
			return nil, metricsErr
		}
		groupCacheSnapshot.metrics = make(map[string]perfmetrics.GroupResult)
		for _, group := range performance.Groups {
			groupCacheSnapshot.metrics[group.Group] = group
		}
		groupCacheSnapshot.updated = now
		groupCacheSnapshot.channels = string(encoded)
	}
	userResults := perfmetrics.LatestUserResults(ctx, order)
	monitors := make([]Monitor, 0, len(order))
	for _, group := range order {
		monitor := Monitor{ID: model.DetectionSecretHash(group)[:16], Name: group, Status: -1, Models: models[group]}
		if monitor.Models == nil {
			monitor.Models = []string{}
		}
		if settings[group].Alias != "" {
			monitor.Name = settings[group].Alias
		}
		if admin {
			monitor.Alias, monitor.Hidden = settings[group].Alias, settings[group].Hidden
		}
		if admin {
			monitor.Group = group
		}
		monitor.Fingerprint = fingerprints[group]
		if monitor.Fingerprint == nil {
			monitor.Fingerprint = &service.AstraSamplingSummary{Enabled: service.AstraSamplingEnabled(), Available: fingerprintErr == nil, History: []service.AstraSamplingHistory{}}
		}
		monitor.ProbeStatus = monitor.Status
		monitor.ChannelDisabled = !active[group]
		if !active[group] {
			monitor.Status = 0
		}
		stats := groupCacheSnapshot.stats[group]
		monitor.CacheStats = &stats
		applyRequestMetrics(&monitor, groupCacheSnapshot.metrics[group])
		if !admin && monitor.Metrics != nil {
			monitor.Metrics.Group = monitor.Name
		}
		monitor.Pelican = detections[group].Pelican
		monitor.ProbeHistory = detections[group].ProbeHistory
		applyCurrentStatus(&monitor, userResults[group], now.Unix())
		monitors = append(monitors, monitor)
	}
	return []UptimeGroupResult{{CategoryName: "Groups", Monitors: monitors}}, nil
}

func GetGroupStatus(c *gin.Context) {
	ctx, cancel := context.WithTimeout(c.Request.Context(), requestTimeout)
	defer cancel()

	results, err := currentGroupMonitors(ctx, false)
	if err != nil {
		common.SysError("group status statistics: " + err.Error())
		c.JSON(http.StatusServiceUnavailable, gin.H{"success": false, "message": "Status data is temporarily unavailable"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "message": "", "data": results})
}

func requestStatus(rate float64) int {
	if rate >= 90 {
		return 1
	}
	if rate >= 70 {
		return 2
	}
	return 0
}

func applyCurrentStatus(monitor *Monitor, result perfmetrics.UserRequestResult, now int64) {
	monitor.Status, monitor.StatusCheckedAt = -1, 0
	monitor.StatusSource = "detection"
	if monitor.ChannelDisabled {
		monitor.Status = 0
		monitor.StatusSource = "disabled"
		return
	}
	// Current availability uses dedicated probes, not quality tests or hourly
	// request ratios. Allow one missed 15-minute probe before evidence expires.
	for _, probe := range monitor.ProbeHistory {
		if probe.At > 0 && probe.At >= now-1800 && probe.At <= now && probe.At >= monitor.StatusCheckedAt {
			monitor.Status = probe.Status
			monitor.StatusCheckedAt = probe.At
		}
	}
	// The latest real user result is stronger evidence than synthetic checks
	// on another member channel, whether it succeeded or failed.
	if at := result.At / 1000; at > 0 && at >= now-900 && at <= now {
		monitor.Status = 0
		if result.Success {
			monitor.Status = 1
		}
		monitor.StatusSource = "requests"
		monitor.StatusCheckedAt = at
	}
}

func applyRequestMetrics(monitor *Monitor, metrics perfmetrics.GroupResult) {
	monitor.Status = -1
	monitor.Uptime = 0
	monitor.Ping = 0
	monitor.LastChecked = ""
	monitor.History = nil
	if len(metrics.Series) > 0 {
		monitor.Metrics = &metrics
		monitor.Uptime = metrics.SuccessRate / 100
		latest := metrics.Series[len(metrics.Series)-1]
		if time.Since(time.Unix(latest.Ts, 0)) <= requestStatusFreshness {
			monitor.Status = requestStatus(latest.SuccessRate)
		}
		for _, point := range metrics.Series {
			monitor.History = append(monitor.History, MonitorSample{
				Status: requestStatus(point.SuccessRate), Ping: int(point.AvgTtftMs),
				Time: time.Unix(point.Ts, 0).UTC().Format("2006-01-02 15:04:05"),
			})
		}
		monitor.LastChecked = monitor.History[len(monitor.History)-1].Time
	}
	if monitor.ChannelDisabled {
		monitor.Status = 0
	}
}