package main

// Program entry point: environment, store bootstrap, startup secret
// scrubbing, admin bootstrap, HTTP server and the 60s housekeeping loop —
// mirroring server.js main() and housekeeping().

import (
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"time"
)

// VERSION is the panel version; do not change (agents and the AnyTLS gate
// parse it numerically).
const VERSION = "0.6.8"

// cookieSecure mirrors NG_COOKIE_SECURE !== 'false'; set in main().
var cookieSecure = true

// ---------- startup scrub helpers ----------

func extraStringValue(ex extraFields, key string) (string, bool) {
	raw, ok := ex[key]
	if !ok {
		return "", false
	}
	var s string
	if err := json.Unmarshal(raw, &s); err != nil {
		return "", false
	}
	return s, true
}

func setExtraString(ex extraFields, key, value string) extraFields {
	if ex == nil {
		ex = extraFields{}
	}
	raw, _ := json.Marshal(value)
	ex[key] = raw
	return ex
}

// extraEngineDetail reads engine.detail when a record carries its engine
// state as an unknown (Extra) field rather than the typed field.
func extraEngineDetail(ex extraFields) (string, bool) {
	raw, ok := ex["engine"]
	if !ok {
		return "", false
	}
	var eng map[string]any
	if err := json.Unmarshal(raw, &eng); err != nil {
		return "", false
	}
	s, ok := eng["detail"].(string)
	return s, ok
}

func setExtraEngineDetail(ex extraFields, value string) {
	raw, ok := ex["engine"]
	if !ok {
		return
	}
	var eng map[string]any
	if err := json.Unmarshal(raw, &eng); err != nil {
		return
	}
	eng["detail"] = value
	out, err := json.Marshal(eng)
	if err == nil {
		ex["engine"] = out
	}
}

func needsScrub(s string) bool {
	return s != "" && s != RedactSecrets(s)
}

// startupNeedsCleaning reports whether any persisted job/node/server still
// holds an un-redacted secret in error/lastError/engine.detail.
func startupNeedsCleaning(d *Data) bool {
	checkExtra := func(ex extraFields) bool {
		for _, key := range []string{"error", "lastError"} {
			if s, ok := extraStringValue(ex, key); ok && needsScrub(s) {
				return true
			}
		}
		if s, ok := extraEngineDetail(ex); ok && needsScrub(s) {
			return true
		}
		return false
	}
	for _, job := range d.Jobs {
		if job.Error != nil && needsScrub(*job.Error) || checkExtra(job.Extra) {
			return true
		}
	}
	for _, node := range d.Nodes {
		if node.Error != nil && needsScrub(*node.Error) || checkExtra(node.Extra) {
			return true
		}
	}
	for _, server := range d.Servers {
		if server.Engine != nil && needsScrub(server.Engine.Detail) || checkExtra(server.Extra) {
			return true
		}
	}
	return false
}

func scrubExtra(ex extraFields) {
	for _, key := range []string{"error", "lastError"} {
		if s, ok := extraStringValue(ex, key); ok && s != "" {
			setExtraString(ex, key, RedactSecrets(s))
		}
	}
	if s, ok := extraEngineDetail(ex); ok && s != "" {
		setExtraEngineDetail(ex, RedactSecrets(s))
	}
}

func scrubRecordSecrets(d *Data) {
	for _, job := range d.Jobs {
		if job.Error != nil && *job.Error != "" {
			redacted := RedactSecrets(*job.Error)
			job.Error = &redacted
		}
		scrubExtra(job.Extra)
	}
	for _, node := range d.Nodes {
		if node.Error != nil && *node.Error != "" {
			redacted := RedactSecrets(*node.Error)
			node.Error = &redacted
		}
		scrubExtra(node.Extra)
	}
	for _, server := range d.Servers {
		if server.Engine != nil && server.Engine.Detail != "" {
			server.Engine.Detail = RedactSecrets(server.Engine.Detail)
		}
		scrubExtra(server.Extra)
	}
}

// ---------- housekeeping ----------

// housekeeping is server.js housekeeping(): offline servers, expired job
// leases, quota suspensions/resumes, retention pruning, access pruning and
// session pruning, every 60 seconds. The transaction result is never SKIP,
// so a successful pass persists.
func (a *App) housekeeping() {
	_, err := a.store.Transaction(func(d *Data) (any, error) {
		now := time.Now().UnixMilli()
		nowISO := NowISO()
		for _, server := range d.Servers {
			if server.LastSeenAt == nil {
				continue
			}
			if ms, ok := ParseISOMs(*server.LastSeenAt); ok && now-ms > 180000 {
				server.Status = "offline"
			}
		}
		for _, job := range d.Jobs {
			if job.Status != "running" || job.LeaseUntil == nil {
				continue
			}
			ms, ok := ParseISOMs(*job.LeaseUntil)
			if !ok || ms > now {
				continue
			}
			job.LeaseUntil = nil
			job.UpdatedAt = nowISO
			if job.Attempts < 3 {
				job.Status = "queued"
				job.Error = StrPtr("Agent 未在租约内确认，任务已自动重试")
			} else {
				job.Status = "failed"
				job.Error = StrPtr("Agent 连续 3 次未在租约内确认")
				if node := findNode(d, job.NodeID); node != nil {
					kind := ""
					if job.Payload != nil {
						kind = job.Payload.KindOf()
					}
					if kind == "node-exit" {
						node.Status = "degraded"
					} else {
						node.Status = "failed"
					}
					node.Error = job.Error
					node.UpdatedAt = nowISO
				}
			}
		}
		// Monthly traffic resets run before the quota evaluation below,
		// so a customer whose new period just started is judged on the
		// zeroed counters (and a reset can lift a traffic suspension in
		// the same pass). Due-ness derives from the persisted period
		// marker, so this also catches up resets missed while the panel
		// was down — at the first pass after it is back (<=60s).
		if err := ApplyMonthlyTrafficResets(d, time.Now()); err != nil {
			return nil, err
		}
		for _, customer := range d.Customers {
			expired := false
			if customer.ExpiresAt != nil {
				if ms, ok := ParseISOMs(*customer.ExpiresAt); ok && ms <= now {
					expired = true
				}
			}
			exhausted := customer.TrafficLimitBytes > 0 && float64(customer.UsedBytes) >= customer.TrafficLimitBytes
			if (expired || exhausted) && customer.Status == "active" {
				customer.Status = "suspended"
				if expired {
					customer.SuspendReason = StrPtr("expired")
					customer.SuspendReasonPresent = true
				} else {
					customer.SuspendReason = StrPtr("traffic_limit")
					customer.SuspendReasonPresent = true
				}
				customer.UpdatedAt = nowISO
				if _, err := SuspendCustomerResources(d, customer, "system:quota"); err != nil {
					return nil, err
				}
			} else if customer.Status == "suspended" && strVal(customer.SuspendReason) == "ip_limit" && CustomerBlockReason(d, customer) == "" {
				customer.Status = "active"
				customer.SuspendReason = nil
				customer.SuspendReasonPresent = true
				customer.UpdatedAt = nowISO
				if _, err := ResumeCustomerResources(d, customer, "system:ip_window"); err != nil {
					return nil, err
				}
			}
		}
		jobRetention := d.Settings.CompletedJobRetentionDays
		if jobRetention == 0 {
			jobRetention = 7
		}
		jobCutoff := now - int64(jobRetention*86400000)
		jobs := d.Jobs[:0]
		for _, job := range d.Jobs {
			if job.Status == "completed" || job.Status == "failed" {
				if ms, ok := ParseISOMs(job.UpdatedAt); !ok || ms <= jobCutoff {
					continue
				}
			}
			jobs = append(jobs, job)
		}
		d.Jobs = jobs
		activityRetention := d.Settings.ActivityRetentionDays
		if activityRetention == 0 {
			activityRetention = 30
		}
		activityCutoff := now - int64(activityRetention*86400000)
		activity := d.Activity[:0]
		for _, event := range d.Activity {
			if ms, ok := ParseISOMs(event.At); ok && ms > activityCutoff {
				activity = append(activity, event)
			}
		}
		if len(activity) > 2000 {
			activity = activity[:2000]
		}
		d.Activity = activity
		PruneAccess(d, time.Now())
		return nil, nil
	})
	if err != nil {
		fmt.Fprintf(os.Stderr, "Housekeeping failed: %v\n", err)
		return
	}
	a.getSessions().Prune()
	// System-status sampling + due external-source refreshes (outside the
	// transaction; fetches must not hold the store lock).
	a.monitor().Sample(a.store.Snapshot(), false)
	a.RefreshDueSources()
}

// ---------- main ----------

func defaultDataFile() string {
	exe, err := os.Executable()
	if err != nil {
		return filepath.Join("data", "nexusgate.json")
	}
	return filepath.Join(filepath.Dir(exe), "data", "nexusgate.json")
}

func run() error {
	dataFile := os.Getenv("NG_DATA_FILE")
	if dataFile == "" {
		dataFile = defaultDataFile()
	}
	host := os.Getenv("NG_HOST")
	if host == "" {
		host = "127.0.0.1"
	}
	port := 8787
	if p := os.Getenv("NG_PORT"); p != "" {
		if n, err := strconv.Atoi(p); err == nil {
			port = n
		}
	}
	cookieSecure = os.Getenv("NG_COOKIE_SECURE") != "false"

	store := NewStore(dataFile)
	if err := store.Init(); err != nil {
		return err
	}
	if startupNeedsCleaning(store.Snapshot()) {
		if _, err := store.Transaction(func(d *Data) (any, error) {
			scrubRecordSecrets(d)
			return nil, nil
		}); err != nil {
			return err
		}
	}
	missingToken := false
	for _, customer := range store.Snapshot().Customers {
		if customer.SubscriptionToken == "" {
			missingToken = true
			break
		}
	}
	if missingToken {
		if _, err := store.Transaction(func(d *Data) (any, error) {
			for _, customer := range d.Customers {
				if customer.SubscriptionToken == "" {
					customer.SubscriptionToken = RandomToken(32)
				}
			}
			return nil, nil
		}); err != nil {
			return err
		}
	}
	if len(store.Snapshot().Users) == 0 {
		password := os.Getenv("NG_ADMIN_PASSWORD")
		generated := false
		if password == "" {
			password = RandomToken(15)
			generated = true
		}
		username := os.Getenv("NG_ADMIN_USERNAME")
		if username == "" {
			username = "admin"
		}
		if _, err := store.Transaction(func(d *Data) (any, error) {
			d.Users = append(d.Users, &User{
				ID:           NewID("usr"),
				Username:     username,
				PasswordHash: HashSecret(password),
				Role:         "owner",
				Status:       "active",
				CreatedAt:    NowISO(),
			})
			return nil, nil
		}); err != nil {
			return err
		}
		if generated {
			fmt.Printf("BOOTSTRAP_PASSWORD=%s\n", password)
		}
	}

	// Node sort order migration (idempotent): unless the stored
	// sortIndex values are exactly the permutation 0..n-1, renumber by
	// storage order. Mirrors the Node implementation's boot migration.
	{
		nodes := store.Snapshot().Nodes
		seen := map[int]bool{}
		valid := true
		for _, node := range nodes {
			if node.SortIndex < 0 || node.SortIndex >= len(nodes) || seen[node.SortIndex] {
				valid = false
				break
			}
			seen[node.SortIndex] = true
		}
		if !valid {
			if _, err := store.Transaction(func(d *Data) (any, error) {
				for index, node := range d.Nodes {
					node.SortIndex = index
				}
				return nil, nil
			}); err != nil {
				return err
			}
		}
	}

	app := NewApp(store, nil, NewOrchestrator(store))
	app.replaceSessions(NewSessionManager(app.sessionHours()))

	server := &http.Server{
		Addr:              host + ":" + strconv.Itoa(port),
		Handler:           app,
		ReadHeaderTimeout: 15 * time.Second,
		ReadTimeout:       30 * time.Second,
	}
	go func() {
		ticker := time.NewTicker(60 * time.Second)
		defer ticker.Stop()
		for range ticker.C {
			app.housekeeping()
		}
	}()
	fmt.Printf("NexusGate v%s listening on http://%s:%d\n", VERSION, host, port)
	return server.ListenAndServe()
}

func main() {
	if err := run(); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}