package admin

import (
	"encoding/json"
	"net/http"
	"os"
	"runtime"
	"runtime/debug"
	"strconv"
	"strings"
	"time"

	"gitea.tbdevent.eu/TBD/reforger_crawler_main/initializers"
	"gitea.tbdevent.eu/TBD/reforger_crawler_main/metrics"
	"gitea.tbdevent.eu/TBD/reforger_crawler_main/models"
	"github.com/gin-gonic/gin"
)

// BuildCommit is set by main from -ldflags.
var BuildCommit = ""

type serviceRow struct {
	models.ServiceInstance
	Online    bool           `json:"online"`
	UptimeSec int64          `json:"uptimeSec"`
	MetaMap   map[string]any `json:"metaData,omitempty"`
}

func listServices(c *gin.Context) {
	var rows []models.ServiceInstance
	if err := initializers.DB.Order("service ASC, instance ASC").Find(&rows).Error; err != nil {
		fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	now := time.Now()
	out := make([]serviceRow, 0, len(rows))
	for _, r := range rows {
		s := serviceRow{ServiceInstance: r, Online: metrics.Online(&r, now)}
		if r.StartedAt > 0 && s.Online {
			s.UptimeSec = now.Unix() - r.StartedAt
		}
		if r.Meta != "" {
			_ = json.Unmarshal([]byte(r.Meta), &s.MetaMap)
		}
		out = append(out, s)
	}
	c.JSON(http.StatusOK, gin.H{"items": out})
}

func deleteService(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		fail(c, http.StatusBadRequest, "invalid id")
		return
	}
	var row models.ServiceInstance
	if err := initializers.DB.First(&row, id).Error; err != nil {
		fail(c, http.StatusNotFound, "not found")
		return
	}
	initializers.DB.Delete(&row)
	audit(c, "service_forget", map[string]any{"service": row.Service, "instance": row.Instance})
	c.JSON(http.StatusOK, gin.H{"deleted": id})
}

type eventRow struct {
	models.ServiceEvent
	FieldsMap map[string]any `json:"fieldsData,omitempty"`
}

func listEvents(c *gin.Context) {
	limit := queryInt(c, "limit", 100, 1, 500)
	q := initializers.DB.Model(&models.ServiceEvent{})
	if v := c.Query("service"); v != "" {
		q = q.Where("service = ?", v)
	}
	if v := c.Query("instance"); v != "" {
		q = q.Where("instance = ?", v)
	}
	if v := c.Query("level"); v != "" {
		levels := strings.Split(v, ",")
		q = q.Where("level IN ?", levels)
	}
	if c.Query("audit") == "1" {
		q = q.Where("fields LIKE ?", `%"kind":"audit"%`)
	}
	if v := strings.TrimSpace(c.Query("q")); v != "" {
		q = q.Where(`LOWER(message) LIKE ? ESCAPE '\'`, "%"+likeEscape(strings.ToLower(v))+"%")
	}
	if before := queryInt64(c, "before", 0); before > 0 {
		q = q.Where("id < ?", before)
	}
	var rows []models.ServiceEvent
	if err := q.Order("id DESC").Limit(limit).Find(&rows).Error; err != nil {
		fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	out := make([]eventRow, 0, len(rows))
	for _, r := range rows {
		e := eventRow{ServiceEvent: r}
		if r.Fields != "" {
			_ = json.Unmarshal([]byte(r.Fields), &e.FieldsMap)
		}
		out = append(out, e)
	}
	var next uint
	if len(rows) == limit {
		next = rows[len(rows)-1].ID
	}
	c.JSON(http.StatusOK, gin.H{"items": out, "next": next})
}

func buildInfo() gin.H {
	info := gin.H{"commit": BuildCommit}
	if bi, ok := debug.ReadBuildInfo(); ok {
		info["module"] = bi.Main.Path
		for _, s := range bi.Settings {
			switch s.Key {
			case "vcs.revision":
				if BuildCommit == "" {
					info["commit"] = s.Value
				}
			case "vcs.time":
				info["time"] = s.Value
			case "vcs.modified":
				info["modified"] = s.Value == "true"
			}
		}
	}
	return info
}

func system(c *gin.Context) {
	var ms runtime.MemStats
	runtime.ReadMemStats(&ms)
	host, _ := os.Hostname()
	started := metrics.StartedAt()

	resp := gin.H{
		"go": gin.H{
			"version": runtime.Version(), "os": runtime.GOOS, "arch": runtime.GOARCH,
			"cpus": runtime.NumCPU(), "maxProcs": runtime.GOMAXPROCS(0), "goroutines": runtime.NumGoroutine(),
		},
		"process": gin.H{
			"pid": os.Getpid(), "hostname": host, "startedAt": started.Unix(),
			"uptimeSec": int64(time.Since(started).Seconds()),
		},
		"memory": gin.H{
			"heapAlloc": ms.HeapAlloc, "heapInuse": ms.HeapInuse, "sys": ms.Sys,
			"numGC": ms.NumGC, "pauseTotalNs": ms.PauseTotalNs, "lastGC": int64(ms.LastGC / 1e9),
		},
		"build":   buildInfo(),
		"metrics": metrics.Status(),
		"config": gin.H{
			"dbDriver":                   initializers.DB.Dialector.Name(),
			"trustedProxies":             initializers.TrustedProxies,
			"cookieSecure":               initializers.AdminCookieSecure,
			"sessionTtlHours":            initializers.AdminSessionTTL.Hours(),
			"metricsEnabled":             initializers.MetricsEnabled,
			"prometheusEndpoint":         initializers.MetricsToken != "",
			"metricsMinuteRetentionDays": initializers.MetricsMinuteRetentionDays,
			"metricsHourRetentionDays":   initializers.MetricsHourRetentionDays,
			"eventsRetentionDays":        initializers.EventsRetentionDays,
			"topItemsRetentionDays":      initializers.TopItemsRetentionDays,
			"indexTimeoutMinutes":        initializers.IndexTimeout.Minutes(),
			"adminSecretStrong":          len(initializers.AdminSecret) >= 16,
			"secretKeySet":               initializers.SecretKey != "",
			"discordWebhook":             initializers.DiscordWebhookURL != "",
			"scraperWebhook":             initializers.ScraperWebhookURL != "",
		},
	}
	if sqlDB, err := initializers.DB.DB(); err == nil {
		st := sqlDB.Stats()
		resp["dbPool"] = gin.H{
			"open": st.OpenConnections, "inUse": st.InUse, "idle": st.Idle,
			"maxOpen": st.MaxOpenConnections, "waitCount": st.WaitCount, "waitMs": st.WaitDuration.Milliseconds(),
		}
		start := time.Now()
		if err := sqlDB.Ping(); err == nil {
			resp["dbPingMs"] = float64(time.Since(start).Microseconds()) / 1000
		} else {
			resp["dbPingError"] = err.Error()
		}
	}
	if h := currentHeavy(); h != nil {
		resp["db"] = h
	}
	c.JSON(http.StatusOK, resp)
}

func maintenance(c *gin.Context) {
	var body struct {
		Action    string `json:"action"`
		OlderDays int    `json:"olderThanDays"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		fail(c, http.StatusBadRequest, "invalid JSON")
		return
	}
	switch body.Action {
	case "refresh-stats":
		requestHeavyRefresh()
		requestDupRefresh()
	case "flush-metrics":
		metrics.FlushAll()
	case "rollup":
		go metrics.RunMaintenance(time.Now())
	case "purge-deleted-files":
		days := body.OlderDays
		if days <= 0 {
			days = 7
		}
		go purgeDeletedFiles(days)
	default:
		fail(c, http.StatusBadRequest, "unknown action")
		return
	}
	audit(c, "maintenance_"+strings.ReplaceAll(body.Action, "-", "_"), map[string]any{"olderThanDays": body.OlderDays})
	c.JSON(http.StatusAccepted, gin.H{"started": body.Action})
}

// purgeDeletedFiles hard-deletes file rows that were soft-deleted (replaced by
// a newer index) more than `days` ago, in batches.
func purgeDeletedFiles(days int) {
	cutoff := time.Now().AddDate(0, 0, -days)
	started := time.Now()
	var total int64
	for {
		res := initializers.DB.Exec(`DELETE FROM addon_files WHERE id IN (
			SELECT id FROM addon_files WHERE deleted_at IS NOT NULL AND deleted_at < ? LIMIT 5000)`, cutoff)
		if res.Error != nil {
			metrics.Event("error", "purge of deleted file rows failed", map[string]any{"kind": "maintenance", "error": res.Error.Error(), "deleted": total})
			return
		}
		total += res.RowsAffected
		if res.RowsAffected == 0 {
			break
		}
		time.Sleep(200 * time.Millisecond)
	}
	metrics.Event("info", "purged deleted file rows", map[string]any{
		"kind": "maintenance", "deleted": total, "olderThanDays": days, "tookSec": int64(time.Since(started).Seconds()),
	})
	requestHeavyRefresh()
}