package service

import (
	"github.com/gochat/gochat/internal/model"
)

// RollupMetricData holds the computed count and value for a single rollup metric.
type RollupMetricData struct {
	Count     int64
	SumValue  float64
	SumBizHours float64
}

// ExpandEventToRollupMetrics maps a raw event metric name to the rollup metrics
// it contributes to. This mirrors Chatwoot's EVENT_METRICS registry.
//
// Chatwoot EVENT_METRICS mapping:
//   conversation_resolved → resolutions_count (count) + resolution_time (duration)
//   first_response        → first_response (duration)
//   reply_time            → reply_time (duration)
//   conversation_bot_resolved → bot_resolutions_count (count)
//   conversation_bot_handoff  → bot_handoffs_count (count)
func ExpandEventToRollupMetrics(rawMetric model.RollupMetric, count int64, sumValue, sumBizHours float64) map[model.RollupMetric]RollupMetricData {
	result := map[model.RollupMetric]RollupMetricData{}

	switch rawMetric {
	case model.RollupMetric("conversation_resolved"):
		// Count metric: resolutions_count
		result[model.MetricResolutionsCount] = RollupMetricData{
			Count:     count,
			SumValue:  float64(count),
			SumBizHours: float64(count),
		}
		// Duration metric: resolution_time
		result[model.MetricResolutionTime] = RollupMetricData{
			Count:     count,
			SumValue:  sumValue,
			SumBizHours: sumBizHours,
		}

	case model.RollupMetric("first_response"):
		result[model.MetricFirstResponse] = RollupMetricData{
			Count:     count,
			SumValue:  sumValue,
			SumBizHours: sumBizHours,
		}

	case model.RollupMetric("reply_time"):
		result[model.MetricReplyTime] = RollupMetricData{
			Count:     count,
			SumValue:  sumValue,
			SumBizHours: sumBizHours,
		}

	case model.RollupMetric("conversation_bot_resolved"):
		result[model.MetricBotResolutionsCount] = RollupMetricData{
			Count:     count,
			SumValue:  float64(count),
			SumBizHours: float64(count),
		}

	case model.RollupMetric("conversation_bot_handoff"):
		result[model.MetricBotHandoffsCount] = RollupMetricData{
			Count:     count,
			SumValue:  float64(count),
			SumBizHours: float64(count),
		}

	default:
		// Unknown metric — still record it as a direct rollup
		result[rawMetric] = RollupMetricData{
			Count:     count,
			SumValue:  sumValue,
			SumBizHours: sumBizHours,
		}
	}

	return result
}

// ReportMetricDefinition describes how a report metric is sourced and aggregated.
// Mirrors Chatwoot REPORT_METRICS registry.
type ReportMetricDefinition struct {
	RawEventName  string         // The raw ReportingEvent name that feeds this metric
	RollupMetric  model.RollupMetric // The rollup metric column to read from
	AggregateType string         // "count", "average", "sum"
}

// ReportMetricsRegistry maps summary response keys to metric definitions.
// Mirrors Chatwoot MetricRegistry::REPORT_METRICS.
var ReportMetricsRegistry = map[string]ReportMetricDefinition{
	"conversations_count":          {AggregateType: "count"},
	"incoming_messages_count":      {AggregateType: "count"},
	"outgoing_messages_count":      {AggregateType: "count"},
	"avg_first_response_time":      {RawEventName: "first_response", RollupMetric: model.MetricFirstResponse, AggregateType: "average"},
	"avg_resolution_time":          {RawEventName: "conversation_resolved", RollupMetric: model.MetricResolutionTime, AggregateType: "average"},
	"reply_time":                   {RawEventName: "reply_time", RollupMetric: model.MetricReplyTime, AggregateType: "average"},
	"resolutions_count":            {RawEventName: "conversation_resolved", RollupMetric: model.MetricResolutionsCount, AggregateType: "count"},
	"bot_resolutions_count":        {RawEventName: "conversation_bot_resolved", RollupMetric: model.MetricBotResolutionsCount, AggregateType: "count"},
	"bot_handoffs_count":           {RawEventName: "conversation_bot_handoff", RollupMetric: model.MetricBotHandoffsCount, AggregateType: "count"},
	"avg_first_response_time_business_hours": {RawEventName: "first_response", RollupMetric: model.MetricFirstResponse, AggregateType: "average_biz"},
	"avg_resolution_time_business_hours":     {RawEventName: "conversation_resolved", RollupMetric: model.MetricResolutionTime, AggregateType: "average_biz"},
	"reply_time_business_hours":              {RawEventName: "reply_time", RollupMetric: model.MetricReplyTime, AggregateType: "average_biz"},
}

// SummaryMetricsMap maps Chatwoot summary API response keys to their
// underlying rollup metric names. Mirrors MetricRegistry::SUMMARY_METRICS.
var SummaryMetricsMap = map[string]model.RollupMetric{
	"resolutions_count":       model.MetricResolutionsCount,
	"avg_resolution_time":     model.MetricResolutionTime,
	"avg_first_response_time": model.MetricFirstResponse,
	"reply_time":              model.MetricReplyTime,
}

// GetReportMetricDefinition returns the metric definition for a given report key.
func GetReportMetricDefinition(key string) *ReportMetricDefinition {
	if def, ok := ReportMetricsRegistry[key]; ok {
		return &def
	}
	return nil
}