package graph

import (
	"context"
	"fmt"

	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
)

// NetworkAnalyzer handles network analysis operations
type NetworkAnalyzer struct {
	sessionManager *SessionManager
	queryTemplates *QueryTemplates
	config         *Config
}

// NewNetworkAnalyzer creates a new network analyzer instance
func NewNetworkAnalyzer(sessionManager *SessionManager, queryTemplates *QueryTemplates, config *Config) *NetworkAnalyzer {
	return &NetworkAnalyzer{
		sessionManager: sessionManager,
		queryTemplates: queryTemplates,
		config:         config,
	}
}

// AnalyzeNetworkCentrality calculates centrality measures for organizations
func (na *NetworkAnalyzer) AnalyzeNetworkCentrality(ctx context.Context) (map[string]*CentralityMetrics, error) {

	result, err := na.sessionManager.ExecuteRead(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		cypher := na.queryTemplates.CalculateCentralityQuery()

		queryResult, err := tx.Run(ctx, cypher, nil)
		if err != nil {
			return nil, fmt.Errorf("failed to execute centrality query: %w", err)
		}

		centralityMap := make(map[string]*CentralityMetrics)
		totalOrgs := 0.0
		maxDegree := 0.0

		// First pass: collect degree centrality
		for queryResult.Next(ctx) {
			record := queryResult.Record()

			orgID, _ := record.Get("org_id")
			degree, _ := record.Get("degree_centrality")
			outFlows, _ := record.Get("out_flows")
			inFlows, _ := record.Get("in_flows")

			orgIDStr := getStringValue(orgID)
			degreeVal := getFloat64Value(degree)

			if degreeVal > maxDegree {
				maxDegree = degreeVal
			}

			centralityMap[orgIDStr] = &CentralityMetrics{
				OrganizationID: orgIDStr,
				Degree:         degreeVal,
				Betweenness:    0.0, // Would need more complex calculation
				Closeness:      0.0, // Would need path analysis
				OutFlows:       getIntValue(outFlows),
				InFlows:        getIntValue(inFlows),
			}
			totalOrgs++
		}

		if err := queryResult.Err(); err != nil {
			return nil, fmt.Errorf("failed to iterate centrality results: %w", err)
		}

		// Normalize degree centrality (0-1 scale)
		if maxDegree > 0 {
			for _, metrics := range centralityMap {
				metrics.Degree = metrics.Degree / maxDegree
			}
		}

		return centralityMap, nil
	})

	if err != nil {
		return nil, err
	}

	return result.(map[string]*CentralityMetrics), nil
}

// GetNetworkStatistics provides overall network statistics
func (na *NetworkAnalyzer) GetNetworkStatistics(ctx context.Context) (*NetworkStatistics, error) {

	result, err := na.sessionManager.ExecuteRead(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		cypher := na.queryTemplates.GetNetworkStatisticsQuery()

		queryResult, err := tx.Run(ctx, cypher, nil)
		if err != nil {
			return nil, fmt.Errorf("failed to execute network statistics query: %w", err)
		}

		if queryResult.Next(ctx) {
			record := queryResult.Record()

			stats := &NetworkStatistics{}

			if val, ok := record.Get("total_organizations"); ok {
				stats.TotalOrganizations = getIntValue(val)
			}
			if val, ok := record.Get("total_resource_flows"); ok {
				stats.TotalResourceFlows = getIntValue(val)
			}
			if val, ok := record.Get("total_matches"); ok {
				stats.TotalMatches = getIntValue(val)
			}
			if val, ok := record.Get("total_economic_value"); ok {
				stats.TotalEconomicValue = getFloat64Value(val)
			}
			if val, ok := record.Get("avg_distance"); ok {
				stats.AverageDistance = getFloat64Value(val)
			}
			if val, ok := record.Get("high_value_matches"); ok {
				stats.HighValueMatches = getIntValue(val)
			}
			if val, ok := record.Get("geographic_span_km"); ok {
				stats.GeographicSpanKm = getFloat64Value(val)
			}

			return stats, nil
		}

		// Return empty stats if no results
		return &NetworkStatistics{}, nil
	})

	if err != nil {
		return nil, err
	}

	return result.(*NetworkStatistics), nil
}

// FindCircularEconomyCycles finds circular resource flow cycles
func (na *NetworkAnalyzer) FindCircularEconomyCycles(ctx context.Context) ([]*CircularEconomyCycle, error) {

	result, err := na.sessionManager.ExecuteRead(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		cypher := na.queryTemplates.FindCircularEconomyCyclesQuery()

		queryResult, err := tx.Run(ctx, cypher, map[string]interface{}{
			"limit": na.config.DefaultResultLimit,
		})
		if err != nil {
			return nil, fmt.Errorf("failed to execute circular economy query: %w", err)
		}

		var cycles []*CircularEconomyCycle
		for queryResult.Next(ctx) {
			record := queryResult.Record()

			cycleLength, _ := record.Get("cycle_length")
			flowIDs, _ := record.Get("flow_ids")
			organizations, _ := record.Get("organizations")
			cycleValue, _ := record.Get("cycle_value")
			orgCount, _ := record.Get("org_count")

			cycle := &CircularEconomyCycle{
				CycleID:       fmt.Sprintf("cycle_%d", len(cycles)+1),
				CycleLength:   getIntValue(cycleLength),
				CycleValue:    getFloat64Value(cycleValue),
				OrgCount:      getIntValue(orgCount),
				FlowIDs:       []string{},
				Organizations: []string{},
			}

			// Convert flow IDs
			if flowIDsSlice, ok := flowIDs.([]interface{}); ok {
				for _, flowID := range flowIDsSlice {
					if flowIDStr, ok := flowID.(string); ok {
						cycle.FlowIDs = append(cycle.FlowIDs, flowIDStr)
					}
				}
			}

			// Convert organizations
			if orgsSlice, ok := organizations.([]interface{}); ok {
				for _, org := range orgsSlice {
					if orgStr, ok := org.(string); ok {
						cycle.Organizations = append(cycle.Organizations, orgStr)
					}
				}
			}

			cycles = append(cycles, cycle)
		}

		if err := queryResult.Err(); err != nil {
			return nil, fmt.Errorf("failed to iterate cycle results: %w", err)
		}

		return cycles, nil
	})

	if err != nil {
		return nil, err
	}

	return result.([]*CircularEconomyCycle), nil
}