// Copyright 2026 Arctel.net
// SPDX-License-Identifier: Apache-2.0

package model

import (
	"context"
	"math"
	"sync"
	"time"

	analyticsmodel "github.com/Rain-kl/Wavelet/internal/model/analytics"
	analyticsrepo "github.com/Rain-kl/Wavelet/internal/repository/analytics"
)

// AccessLogInsertHooks queues node access logs for async ClickHouse write.
// Wired from openflare/chwriter.Init so model never imports the apps layer.
type AccessLogInsertHooks struct {
	QueueNodeAccessLogs func(logs []analyticsmodel.NodeAccessLog)
}

var (
	accessLogInsertHooksMu sync.RWMutex
	accessLogInsertHooks   AccessLogInsertHooks
)

// SetAccessLogInsertHooks registers async queue callbacks for access log inserts.
func SetAccessLogInsertHooks(hooks AccessLogInsertHooks) {
	accessLogInsertHooksMu.Lock()
	accessLogInsertHooks = hooks
	accessLogInsertHooksMu.Unlock()
}

func currentAccessLogInsertHooks() AccessLogInsertHooks {
	accessLogInsertHooksMu.RLock()
	defer accessLogInsertHooksMu.RUnlock()
	return accessLogInsertHooks
}

type accessLogStore interface {
	InsertBatch(ctx context.Context, records []*OpenFlareAccessLog) error
	List(ctx context.Context, query OpenFlareAccessLogQuery) ([]*OpenFlareAccessLog, error)
	Count(ctx context.Context, query OpenFlareAccessLogQuery) (int64, int64, int64, error)
	RegionCounts(ctx context.Context, nodeID string, since time.Time, limit int) ([]*OpenFlareAccessLogRegionCount, error)
	BucketAggregates(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) ([]openFlareAccessLogBucketAggregateRow, error)
	CountBuckets(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) (int64, error)
	BucketDimensions(ctx context.Context, filter OpenFlareAccessLogQuery, column string, bucketSeconds int64) ([]openFlareAccessLogBucketDimensionRow, error)
	IPAggregates(ctx context.Context, filter OpenFlareAccessLogQuery, exactRemoteAddr bool) ([]openFlareAccessLogIPAggregateRow, error)
	WAFIPAggregates(ctx context.Context, filter OpenFlareAccessLogQuery) ([]openFlareAccessLogWAFIPAggregateRow, error)
	IPSummaries(ctx context.Context, filter OpenFlareAccessLogQuery, recentSince time.Time) ([]openFlareAccessLogIPSummaryRow, error)
	CountIPSummaries(ctx context.Context, filter OpenFlareAccessLogQuery) (int64, error)
	IPTrend(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) ([]openFlareAccessLogIPTrendRow, error)
	TrafficSummary(ctx context.Context, filter OpenFlareAccessLogQuery) (OpenFlareAccessLogTrafficSummary, error)
	ValueCounts(ctx context.Context, filter OpenFlareAccessLogQuery, column string, limit int) ([]OpenFlareAccessLogValueCount, error)
	NodeAggregates(ctx context.Context, filter OpenFlareAccessLogQuery) ([]OpenFlareAccessLogNodeAggregate, error)
	DeleteAll(ctx context.Context) (int64, error)
	DeleteBefore(ctx context.Context, cutoff time.Time) (int64, error)
	DeleteByNodeBefore(ctx context.Context, nodeID string, before time.Time) (int64, error)
}

// OpenFlareAccessLogTrafficSummary is a window-level traffic summary from access logs.
type OpenFlareAccessLogTrafficSummary struct {
	RequestCount  int64
	ErrorCount    int64
	UniqueIPCount int64
	BytesSent     int64
	RequestLength int64
	NodeCount     int64
}

// OpenFlareAccessLogValueCount is a dimension value count.
type OpenFlareAccessLogValueCount struct {
	Value string
	Count int64
}

// OpenFlareAccessLogNodeAggregate is per-node traffic over a window.
type OpenFlareAccessLogNodeAggregate struct {
	NodeID        string
	RequestCount  int64
	ErrorCount    int64
	UniqueIPCount int64
}

var (
	accessLogStoreMu     sync.RWMutex
	accessLogStoreHolder accessLogStore
)

func currentAccessLogStore() accessLogStore {
	accessLogStoreMu.RLock()
	defer accessLogStoreMu.RUnlock()
	if accessLogStoreHolder != nil {
		return accessLogStoreHolder
	}
	return clickhouseAccessLogStore{}
}

// SetAccessLogStoreForTest swaps the access log store implementation for unit tests.
func SetAccessLogStoreForTest(store accessLogStore) func() {
	accessLogStoreMu.Lock()
	previous := accessLogStoreHolder
	accessLogStoreHolder = store
	accessLogStoreMu.Unlock()
	return func() {
		accessLogStoreMu.Lock()
		accessLogStoreHolder = previous
		accessLogStoreMu.Unlock()
	}
}

// NewMemoryAccessLogStore returns an in-memory access log store for unit tests.
func NewMemoryAccessLogStore() accessLogStore {
	return &memoryAccessLogStore{
		records: make([]*OpenFlareAccessLog, 0),
	}
}

type clickhouseAccessLogStore struct{}

func (clickhouseAccessLogStore) InsertBatch(_ context.Context, records []*OpenFlareAccessLog) error {
	logs := make([]analyticsmodel.NodeAccessLog, 0, len(records))
	for _, record := range records {
		if record == nil {
			continue
		}
		logs = append(logs, toAnalyticsNodeAccessLog(record))
	}
	if hook := currentAccessLogInsertHooks().QueueNodeAccessLogs; hook != nil {
		hook(logs)
	}
	return nil
}

func (clickhouseAccessLogStore) List(ctx context.Context, query OpenFlareAccessLogQuery) ([]*OpenFlareAccessLog, error) {
	rows, err := analyticsrepo.ListNodeAccessLogs(ctx, toNodeAccessLogFilter(query))
	if err != nil {
		return nil, err
	}
	return fromAnalyticsNodeAccessLogs(rows), nil
}

func (clickhouseAccessLogStore) Count(ctx context.Context, query OpenFlareAccessLogQuery) (int64, int64, int64, error) {
	return analyticsrepo.CountNodeAccessLogs(ctx, toNodeAccessLogFilter(query))
}

func (clickhouseAccessLogStore) RegionCounts(ctx context.Context, nodeID string, since time.Time, limit int) ([]*OpenFlareAccessLogRegionCount, error) {
	rows, err := analyticsrepo.RegionCountsNodeAccessLogs(ctx, nodeID, since, limit)
	if err != nil {
		return nil, err
	}
	result := make([]*OpenFlareAccessLogRegionCount, len(rows))
	for index, row := range rows {
		result[index] = &OpenFlareAccessLogRegionCount{
			Region: row.Region,
			Count:  row.Count,
		}
	}
	return result, nil
}

func (clickhouseAccessLogStore) BucketAggregates(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) ([]openFlareAccessLogBucketAggregateRow, error) {
	return analyticsrepo.BucketAggregatesNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), bucketSeconds)
}

func (clickhouseAccessLogStore) CountBuckets(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) (int64, error) {
	return analyticsrepo.CountBucketAggregatesNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), bucketSeconds)
}

func (clickhouseAccessLogStore) BucketDimensions(ctx context.Context, filter OpenFlareAccessLogQuery, column string, bucketSeconds int64) ([]openFlareAccessLogBucketDimensionRow, error) {
	return analyticsrepo.BucketDimensionsNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), column, bucketSeconds)
}

func (clickhouseAccessLogStore) IPAggregates(ctx context.Context, filter OpenFlareAccessLogQuery, exactRemoteAddr bool) ([]openFlareAccessLogIPAggregateRow, error) {
	return analyticsrepo.IPAggregatesNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), exactRemoteAddr)
}

func (clickhouseAccessLogStore) IPSummaries(ctx context.Context, filter OpenFlareAccessLogQuery, recentSince time.Time) ([]openFlareAccessLogIPSummaryRow, error) {
	return analyticsrepo.IPSummariesNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), recentSince)
}

func (clickhouseAccessLogStore) CountIPSummaries(ctx context.Context, filter OpenFlareAccessLogQuery) (int64, error) {
	return analyticsrepo.CountIPSummaryNodeAccessLogs(ctx, toNodeAccessLogFilter(filter))
}

func (clickhouseAccessLogStore) WAFIPAggregates(ctx context.Context, filter OpenFlareAccessLogQuery) ([]openFlareAccessLogWAFIPAggregateRow, error) {
	return analyticsrepo.IPAggregatesForWAFNodeAccessLogs(ctx, toNodeAccessLogFilter(filter))
}

func (clickhouseAccessLogStore) IPTrend(ctx context.Context, filter OpenFlareAccessLogQuery, bucketSeconds int64) ([]openFlareAccessLogIPTrendRow, error) {
	return analyticsrepo.IPTrendNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), bucketSeconds)
}

func (clickhouseAccessLogStore) DeleteAll(ctx context.Context) (int64, error) {
	return analyticsrepo.DeleteAllNodeAccessLogs(ctx)
}

func (clickhouseAccessLogStore) DeleteBefore(ctx context.Context, cutoff time.Time) (int64, error) {
	return analyticsrepo.DeleteNodeAccessLogsBefore(ctx, cutoff)
}

func (clickhouseAccessLogStore) DeleteByNodeBefore(ctx context.Context, nodeID string, before time.Time) (int64, error) {
	return analyticsrepo.DeleteNodeAccessLogsByNodeBefore(ctx, nodeID, before)
}

func (clickhouseAccessLogStore) TrafficSummary(ctx context.Context, filter OpenFlareAccessLogQuery) (OpenFlareAccessLogTrafficSummary, error) {
	row, err := analyticsrepo.TrafficSummaryNodeAccessLogs(ctx, toNodeAccessLogFilter(filter))
	if err != nil {
		return OpenFlareAccessLogTrafficSummary{}, err
	}
	return OpenFlareAccessLogTrafficSummary{
		RequestCount:  row.RequestCount,
		ErrorCount:    row.ErrorCount,
		UniqueIPCount: row.UniqueIPCount,
		BytesSent:     row.BytesSent,
		RequestLength: row.RequestLength,
		NodeCount:     row.NodeCount,
	}, nil
}

func (clickhouseAccessLogStore) ValueCounts(ctx context.Context, filter OpenFlareAccessLogQuery, column string, limit int) ([]OpenFlareAccessLogValueCount, error) {
	rows, err := analyticsrepo.ValueCountsNodeAccessLogs(ctx, toNodeAccessLogFilter(filter), column, limit)
	if err != nil {
		return nil, err
	}
	result := make([]OpenFlareAccessLogValueCount, len(rows))
	for i, row := range rows {
		result[i] = OpenFlareAccessLogValueCount{Value: row.Value, Count: row.Count}
	}
	return result, nil
}

func (clickhouseAccessLogStore) NodeAggregates(ctx context.Context, filter OpenFlareAccessLogQuery) ([]OpenFlareAccessLogNodeAggregate, error) {
	rows, err := analyticsrepo.NodeAggregatesNodeAccessLogs(ctx, toNodeAccessLogFilter(filter))
	if err != nil {
		return nil, err
	}
	result := make([]OpenFlareAccessLogNodeAggregate, len(rows))
	for i, row := range rows {
		result[i] = OpenFlareAccessLogNodeAggregate{
			NodeID:        row.NodeID,
			RequestCount:  row.RequestCount,
			ErrorCount:    row.ErrorCount,
			UniqueIPCount: row.UniqueIPCount,
		}
	}
	return result, nil
}

func toNodeAccessLogFilter(query OpenFlareAccessLogQuery) analyticsrepo.NodeAccessLogFilter {
	return analyticsrepo.NodeAccessLogFilter{
		NodeID:     query.NodeID,
		RemoteAddr: query.RemoteAddr,
		Host:       query.Host,
		Hosts:      query.Hosts,
		Path:       query.Path,
		Since:      query.Since,
		Until:      query.Until,
		Page:       query.Page,
		PageSize:   query.PageSize,
		SortBy:     query.SortBy,
		SortOrder:  query.SortOrder,
	}
}

func toAnalyticsNodeAccessLog(record *OpenFlareAccessLog) analyticsmodel.NodeAccessLog {
	var bytesSent uint64
	if record.BytesSent > 0 {
		bytesSent = uint64(record.BytesSent)
	}
	var requestLength uint64
	if record.RequestLength > 0 {
		requestLength = uint64(record.RequestLength)
	}
	var requestTimeMs uint32
	if record.RequestTimeMs > 0 && record.RequestTimeMs <= int64(math.MaxUint32) {
		requestTimeMs = uint32(record.RequestTimeMs)
	}
	return analyticsmodel.NodeAccessLog{
		ID:            record.ID,
		NodeID:        record.NodeID,
		LoggedAt:      record.LoggedAt,
		RemoteAddr:    record.RemoteAddr,
		Region:        record.Region,
		Host:          record.Host,
		Path:          record.Path,
		UserAgent:     record.UserAgent,
		CacheStatus:   record.CacheStatus,
		StatusCode:    openFlareAccessLogStatusCodeToInt32(record.StatusCode),
		BytesSent:     bytesSent,
		RequestLength: requestLength,
		RequestTimeMs: requestTimeMs,
		CreatedAt:     record.CreatedAt,
	}
}

func fromAnalyticsNodeAccessLogs(rows []analyticsmodel.NodeAccessLog) []*OpenFlareAccessLog {
	result := make([]*OpenFlareAccessLog, len(rows))
	for index, row := range rows {
		var bytesSent int64
		if row.BytesSent <= math.MaxInt64 {
			bytesSent = int64(row.BytesSent)
		} else {
			bytesSent = math.MaxInt64
		}
		var requestLength int64
		if row.RequestLength <= math.MaxInt64 {
			requestLength = int64(row.RequestLength)
		} else {
			requestLength = math.MaxInt64
		}
		result[index] = &OpenFlareAccessLog{
			ID:            row.ID,
			NodeID:        row.NodeID,
			LoggedAt:      row.LoggedAt,
			RemoteAddr:    row.RemoteAddr,
			Region:        row.Region,
			Host:          row.Host,
			Path:          row.Path,
			UserAgent:     row.UserAgent,
			CacheStatus:   row.CacheStatus,
			StatusCode:    int(row.StatusCode),
			BytesSent:     bytesSent,
			RequestLength: requestLength,
			RequestTimeMs: int64(row.RequestTimeMs),
			CreatedAt:     row.CreatedAt,
		}
	}
	return result
}