package iot

import (
	"context"
	"strings"

	"github.com/gogf/gf/v2/errors/gcode"
	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"

	v1 "git.5iot.com/iotlcm-public/iotlcm-admin-svr/api/iot/v1"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/dao"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/library/contexts"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/model"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/service"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/service/fullsyncretry"
)

type FullSyncMonitorController struct {
	client fullsyncretry.Client
}

func NewFullSyncMonitor() *FullSyncMonitorController {
	return &FullSyncMonitorController{client: fullsyncretry.FromEnvironment()}
}

func (c *FullSyncMonitorController) List(ctx context.Context, req *v1.FullSyncRunsListReq) (*v1.FullSyncRunsListRes, error) {
	result, err := c.client.ListRuns(ctx, req.SyncKind, req.Limit)
	if err != nil {
		return nil, err
	}
	return &v1.FullSyncRunsListRes{Items: result.Items, Total: result.Total}, nil
}

func (c *FullSyncMonitorController) Detail(ctx context.Context, req *v1.FullSyncRunDetailReq) (*v1.FullSyncRunDetailRes, error) {
	view, err := c.client.Run(ctx, req.RunID)
	if err != nil {
		return nil, err
	}
	kind, name := fullSyncKindName(view.Run.Operation)
	return &v1.FullSyncRunDetailRes{RunView: view, SyncKind: kind, SyncName: name}, nil
}

func (c *FullSyncMonitorController) Failures(ctx context.Context, req *v1.FullSyncRunFailuresReq) (*v1.FullSyncRunFailuresRes, error) {
	page, err := c.client.Failures(ctx, req.RunID, req.Limit, req.Cursor)
	if err != nil {
		return nil, err
	}
	return &v1.FullSyncRunFailuresRes{Items: page.Items, NextCursor: page.NextCursor}, nil
}

func (c *FullSyncMonitorController) Start(ctx context.Context, req *v1.FullSyncRunStartReq) (*v1.FullSyncRunStartRes, error) {
	userID := contexts.GetUserId(ctx)
	if userID == 0 {
		return nil, gerror.NewCode(gcode.CodeNotAuthorized, "Login required")
	}
	if !fullsyncretry.ValidSyncKind(req.SyncKind) {
		return nil, gerror.NewCode(gcode.CodeInvalidParameter, "Invalid full-sync type")
	}
	// A period field only applies to its own sync kind. Rejecting a stray field
	// keeps an operator from believing a backfill was scheduled when it was not.
	period, err := resolvePeriod(req)
	if err != nil {
		return nil, err
	}
	// Validate and canonicalize the channel scope before the active-run check so
	// a malformed request fails fast without touching Worker state.
	scope, err := model.NormalizeScope(&model.SyncScope{Channels: req.Channels, TriggerSource: model.TriggerSourceManual})
	if err != nil {
		return nil, gerror.NewCode(gcode.CodeInvalidParameter, err.Error())
	}
	list, err := c.client.ListRuns(ctx, req.SyncKind, 100)
	if err != nil {
		return nil, err
	}
	for _, item := range list.Items {
		if item.Run.Status == "producing" || item.Run.Status == "running" {
			return nil, gerror.NewCode(gcode.CodeInvalidParameter, "A full-sync run is already active")
		}
	}
	var runID string
	switch req.SyncKind {
	case "traffic_usage":
		runID, err = service.TrafficUsageMonthlySync().StartMonthlyRunScoped(ctx, scope)
	case "sim_status":
		runID, err = service.SimStatusQueue().StartFullSyncRunScoped(ctx, scope)
	case "imei":
		runID, err = service.ImeiQueue().StartImeiRunScoped(ctx, scope)
	case "traffic_usage_daily":
		runID, err = service.TrafficUsageDailySync().StartDailyRunScopedAt(ctx, scope, req.QueryDate)
	case "traffic_usage_monthly":
		runID, err = service.TrafficUsageMonthlySync().StartMonthlyHistoryRunScopedAt(ctx, scope, req.QueryMonth)
	}
	if err != nil {
		g.Log().Warningf(ctx, "full_sync_manual_start rejected actor=%d syncKind=%s scopeChannels=%d period=%s error=%q", userID, req.SyncKind, scope.ChannelCount(), period, err.Error())
		return nil, err
	}
	g.Log().Infof(ctx, "full_sync_manual_start accepted actor=%d syncKind=%s runId=%s scopeChannels=%d scopeSample=%s period=%s", userID, req.SyncKind, runID, scope.ChannelCount(), strings.Join(scope.ChannelSample(10), ","), period)
	return &v1.FullSyncRunStartRes{RunID: runID, SyncKind: req.SyncKind, Status: "published", ScopeChannels: scope.ChannelCount(), QueryPeriod: period}, nil
}

// resolvePeriod returns the requested backfill period for req.SyncKind and
// rejects a period field that does not belong to that sync kind.
func resolvePeriod(req *v1.FullSyncRunStartReq) (string, error) {
	if req.QueryDate != "" && req.SyncKind != "traffic_usage_daily" {
		return "", gerror.NewCodef(gcode.CodeInvalidParameter, "queryDate is only valid for syncKind=traffic_usage_daily, got %s", req.SyncKind)
	}
	if req.QueryMonth != "" && req.SyncKind != "traffic_usage_monthly" {
		return "", gerror.NewCodef(gcode.CodeInvalidParameter, "queryMonth is only valid for syncKind=traffic_usage_monthly, got %s", req.SyncKind)
	}
	switch req.SyncKind {
	case "traffic_usage_daily":
		return req.QueryDate, nil
	case "traffic_usage_monthly":
		return req.QueryMonth, nil
	}
	return "", nil
}

// Channels returns the channels a partial sync can target, with their card
// counts so an operator can judge the blast radius before selecting.
func (c *FullSyncMonitorController) Channels(ctx context.Context, _ *v1.FullSyncChannelOptionsReq) (*v1.FullSyncChannelOptionsRes, error) {
	if contexts.GetUserId(ctx) == 0 {
		return nil, gerror.NewCode(gcode.CodeNotAuthorized, "Login required")
	}
	tenantID := contexts.GetTenantId(ctx)
	type channelRow struct {
		ChanKey     string `orm:"chan_key"`
		ChanName    string `orm:"chan_name"`
		TempKey     string `orm:"temp_key"`
		Operator    int    `orm:"operator"`
		SyncEnabled int    `orm:"sync_enabled"`
		CardCount   int64  `orm:"card_count"`
	}
	var rows []*channelRow
	channels := dao.TSimChannels.Columns()
	cards := dao.TSimCardInfo.Columns()
	// Count cards per channel in one pass. The left join keeps channels that
	// currently hold no cards so they stay selectable (and visibly empty), and
	// both sides are tenant-scoped so the count cannot leak across tenants.
	//
	// The select list and the GROUP BY clause must be built from the same
	// column set; see channelOptionsQuery for why.
	query := channelOptionsQuery(channelQueryColumns{
		ChanKey:     channels.ChanKey,
		ChanName:    channels.ChanName,
		TempKey:     channels.TempKey,
		Operator:    channels.Operator,
		SyncEnabled: channels.SyncEnabled,
		TenantID:    channels.TenantId,
	}, cardQueryColumns{
		Id:       cards.Id,
		ChanKey:  cards.ChanKey,
		TenantID: cards.TenantId,
	}, tenantID)
	err := dao.TSimChannels.Ctx(ctx).
		As(query.alias).
		LeftJoin(query.joinTable, query.joinOn).
		Fields(query.fields...).
		Where(query.tenantWhere, query.tenantID).
		Group(query.groupBy...).
		OrderAsc(query.orderBy).
		Scan(&rows)
	if err != nil {
		return nil, gerror.Wrap(err, "load full-sync channel options failed")
	}
	items := make([]v1.FullSyncChannelOption, 0, len(rows))
	for _, row := range rows {
		if row == nil {
			continue
		}
		items = append(items, v1.FullSyncChannelOption{
			ChanKey:     row.ChanKey,
			ChanName:    row.ChanName,
			TempKey:     row.TempKey,
			Operator:    row.Operator,
			CardCount:   row.CardCount,
			SyncEnabled: row.SyncEnabled == 1,
		})
	}
	return &v1.FullSyncChannelOptionsRes{Items: items}, nil
}

func fullSyncKindName(operation string) (string, string) {
	switch operation {
	case "current_month_usage_full_sync":
		return "traffic_usage", "流量全量同步"
	case "sim_status_queue_full_sync":
		return "sim_status", "卡状态全量同步"
	case "previous_day_usage_full_sync":
		return "traffic_usage_daily", "日流量全量同步"
	case "previous_month_usage_full_sync":
		return "traffic_usage_monthly", "月流量历史全量同步"
	case "imei_full_sync":
		return "imei", "IMEI 全量同步"
	default:
		return "", operation
	}
}

// channelQueryColumns / cardQueryColumns carry the physical column names the
// channel-options query needs. They keep the builder a pure function so its
// SQL shape can be asserted in a unit test.
type channelQueryColumns struct {
	ChanKey     string
	ChanName    string
	TempKey     string
	Operator    string
	SyncEnabled string
	TenantID    string
}

type cardQueryColumns struct {
	Id       string
	ChanKey  string
	TenantID string
}

// channelOptionsQueryShape holds the assembled pieces of the channel-options query
// so the SQL shape can be asserted without a database.
type channelOptionsQueryShape struct {
	alias       string
	joinTable   string
	joinOn      string
	fields      []any
	groupBy     []any
	orderBy     string
	tenantWhere string
	tenantID    string
}

// channelOptionsQuery builds the channel candidate query.
//
// IMPORTANT: every non-aggregate column in the select list must also appear in
// GROUP BY. MySQL runs with ONLY_FULL_GROUP_BY, and GoFrame sends the tenant
// filter as a prepared-statement parameter. A bound parameter is not a
// constant, so MySQL cannot use the unique key uk_key(tenant_id, chan_key) to
// prove that chan_name/temp_key/operator/sync_enabled are functionally
// dependent on the grouped column. Grouping by chan_key alone therefore fails
// in production with:
//
//	Error 1055: Expression #2 of SELECT list is not in GROUP BY clause and
//	contains nonaggregated column 'db_iotlcm.c.chan_name' which is not
//	functionally dependent on columns in GROUP BY clause
//
// Adding the remaining columns keeps the grouping semantically identical
// because (tenant_id, chan_key) is unique, and it satisfies the SQL mode.
func channelOptionsQuery(channels channelQueryColumns, cards cardQueryColumns, tenantID string) channelOptionsQueryShape {
	const alias = "c"
	const joinAlias = "ci"

	// Single source of truth: the non-aggregate columns that are both selected
	// and grouped.
	nonAggregate := []struct{ column, out string }{
		{channels.ChanKey, "chan_key"},
		{channels.ChanName, "chan_name"},
		{channels.TempKey, "temp_key"},
		{channels.Operator, "operator"},
		{channels.SyncEnabled, "sync_enabled"},
	}

	fields := make([]any, 0, len(nonAggregate)+1)
	groupBy := make([]any, 0, len(nonAggregate))
	for _, column := range nonAggregate {
		fields = append(fields, alias+"."+column.column+" AS "+column.out)
		groupBy = append(groupBy, alias+"."+column.column)
	}
	fields = append(fields, "COUNT("+joinAlias+"."+cards.Id+") AS card_count")

	return channelOptionsQueryShape{
		alias:     alias,
		joinTable: dao.TSimCardInfo.Table() + " AS " + joinAlias,
		joinOn: alias + "." + channels.ChanKey + " = " + joinAlias + "." + cards.ChanKey +
			" AND " + joinAlias + "." + cards.TenantID + " = " + alias + "." + channels.TenantID,
		fields:      fields,
		groupBy:     groupBy,
		orderBy:     alias + "." + channels.ChanKey,
		tenantWhere: alias + "." + channels.TenantID,
		tenantID:    tenantID,
	}
}