package repository

import (
	"bugulma/backend/internal/domain"
	"context"
	"encoding/json"
	"fmt"
	"time"

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

// GraphSiteRepository manages Site nodes in Neo4j
type GraphSiteRepository struct {
	driver   neo4j.DriverWithContext
	database string
}

// NewGraphSiteRepository creates a new graph site repository
func NewGraphSiteRepository(driver neo4j.DriverWithContext, dbName string) *GraphSiteRepository {
	return &GraphSiteRepository{
		driver:   driver,
		database: dbName,
	}
}

// SyncToGraph syncs a site to the graph database and creates OPERATES_AT relationship
func (r *GraphSiteRepository) SyncToGraph(ctx context.Context, site *domain.Site) error {
	session := r.driver.NewSession(ctx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeWrite,
		DatabaseName: r.database,
	})
	defer session.Close(ctx)

	// Use ExecuteWrite for automatic retry logic
	_, err := session.ExecuteWrite(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		// Marshal JSONB fields
		availableUtilitiesJSON, _ := json.Marshal(site.AvailableUtilities)
		wasteManagementJSON, _ := json.Marshal(site.WasteManagement)
		sourcesJSON, _ := json.Marshal(site.Sources)

		// Create/update Site node
		siteCypher := `
			MERGE (s:Site {id: $id})
			SET s.name = $name,
				s.site_type = $site_type,
				s.floor_area_m2 = $floor_area_m2,
				s.ownership = $ownership,
				s.latitude = $latitude,
				s.longitude = $longitude,
				s.owner_organization_id = $owner_organization_id,
				s.available_utilities = $available_utilities,
				s.parking_spaces = $parking_spaces,
				s.loading_docks = $loading_docks,
				s.crane_capacity_tonnes = $crane_capacity_tonnes,
				s.energy_rating = $energy_rating,
				s.waste_management = $waste_management,
				s.environmental_impact = $environmental_impact,
				s.year_built = $year_built,
				s.builder_owner = $builder_owner,
				s.architect = $architect,
				s.original_purpose = $original_purpose,
				s.current_use = $current_use,
				s.style = $style,
				s.materials = $materials,
				s.storeys = $storeys,
				s.heritage_status = $heritage_status,
				s.notes = $notes,
				s.sources = $sources,
				s.created_at = $created_at,
				s.updated_at = $updated_at
		`

		// Add location point if coordinates are available
		if site.Latitude != 0 && site.Longitude != 0 {
			siteCypher += `, s.location = point({latitude: $latitude, longitude: $longitude})`
		}

		siteCypher += `
			RETURN s.id
		`

		siteParams := map[string]interface{}{
			"id":                    site.ID,
			"name":                  site.Name,
			"site_type":             site.SiteType,
			"floor_area_m2":         site.FloorAreaM2,
			"ownership":             site.Ownership,
			"latitude":              site.Latitude,
			"longitude":             site.Longitude,
			"owner_organization_id": site.OwnerOrganizationID,
			"available_utilities":   string(availableUtilitiesJSON),
			"parking_spaces":        site.ParkingSpaces,
			"loading_docks":         site.LoadingDocks,
			"crane_capacity_tonnes": site.CraneCapacityTonnes,
			"energy_rating":         site.EnergyRating,
			"waste_management":      string(wasteManagementJSON),
			"environmental_impact":  site.EnvironmentalImpact,
			"year_built":            site.YearBuilt,
			"builder_owner":         site.BuilderOwner,
			"architect":             site.Architect,
			"original_purpose":      site.OriginalPurpose,
			"current_use":           site.CurrentUse,
			"style":                 site.Style,
			"materials":             site.Materials,
			"storeys":               site.Storeys,
			"heritage_status":       site.HeritageStatus,
			"notes":                 site.Notes,
			"sources":               string(sourcesJSON),
			"created_at":            site.CreatedAt.Format(time.RFC3339),
			"updated_at":            site.UpdatedAt.Format(time.RFC3339),
		}

		result, err := tx.Run(ctx, siteCypher, siteParams)
		if err != nil {
			return nil, fmt.Errorf("failed to execute site merge: %w", err)
		}

		if err := result.Err(); err != nil {
			return nil, fmt.Errorf("failed to consume site result: %w", err)
		}

		// Create OPERATES_AT relationship if owner organization exists
		if site.OwnerOrganizationID != "" {
			relCypher := `
				MATCH (s:Site {id: $site_id})
				OPTIONAL MATCH (o:Organization {id: $org_id})
				FOREACH (_ IN CASE WHEN o IS NOT NULL THEN [1] ELSE [] END |
					MERGE (o)-[:OPERATES_AT]->(s)
				)
			`

			relParams := map[string]interface{}{
				"site_id": site.ID,
				"org_id":  site.OwnerOrganizationID,
			}

			relResult, err := tx.Run(ctx, relCypher, relParams)
			if err != nil {
				return nil, fmt.Errorf("failed to create OPERATES_AT relationship: %w", err)
			}

			if err := relResult.Err(); err != nil {
				return nil, fmt.Errorf("failed to consume relationship result: %w", err)
			}
		}

		return nil, nil
	})

	return err
}

// DeleteFromGraph deletes a site from the graph database
func (r *GraphSiteRepository) DeleteFromGraph(ctx context.Context, id string) error {
	session := r.driver.NewSession(ctx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeWrite,
		DatabaseName: r.database,
	})
	defer session.Close(ctx)

	_, err := session.ExecuteWrite(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		cypher := `
			MATCH (s:Site {id: $id})
			DETACH DELETE s
		`

		result, err := tx.Run(ctx, cypher, map[string]interface{}{"id": id})
		if err != nil {
			return nil, fmt.Errorf("failed to delete site: %w", err)
		}

		if err := result.Err(); err != nil {
			return nil, fmt.Errorf("failed to consume delete result: %w", err)
		}

		return nil, nil
	})

	return err
}

// GetByID retrieves a site from the graph
func (r *GraphSiteRepository) GetByID(ctx context.Context, id string) (*domain.Site, error) {
	session := r.driver.NewSession(ctx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeRead,
		DatabaseName: r.database,
	})
	defer session.Close(ctx)

	result, err := session.ExecuteRead(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		cypher := `
			MATCH (s:Site {id: $id})
			RETURN s
		`

		result, err := tx.Run(ctx, cypher, map[string]interface{}{"id": id})
		if err != nil {
			return nil, err
		}

		if result.Next(ctx) {
			record := result.Record()
			node, ok := record.Get("s")
			if !ok {
				return nil, fmt.Errorf("site node not found in result")
			}

			return r.nodeToSite(node.(neo4j.Node))
		}

		return nil, fmt.Errorf("site not found: %s", id)
	})

	if err != nil {
		return nil, err
	}

	return result.(*domain.Site), nil
}

// GetNearby finds sites within a radius using spatial queries
func (r *GraphSiteRepository) GetNearby(ctx context.Context, lat, lng, radiusKm float64, limit int) ([]*domain.Site, error) {
	session := r.driver.NewSession(ctx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeRead,
		DatabaseName: r.database,
	})
	defer session.Close(ctx)

	result, err := session.ExecuteRead(ctx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		// Use point.distance for spatial queries
		cypher := `
			MATCH (s:Site)
			WHERE s.latitude IS NOT NULL AND s.longitude IS NOT NULL
			WITH s, point.distance(
				point({latitude: $lat, longitude: $lng}),
				point({latitude: s.latitude, longitude: s.longitude})
			) / 1000.0 AS distance_km
			WHERE distance_km <= $radius_km
			RETURN s, distance_km
			ORDER BY distance_km
			LIMIT $limit
		`

		params := map[string]interface{}{
			"lat":       lat,
			"lng":       lng,
			"radius_km": radiusKm,
			"limit":     limit,
		}

		result, err := tx.Run(ctx, cypher, params)
		if err != nil {
			return nil, err
		}

		var sites []*domain.Site
		for result.Next(ctx) {
			record := result.Record()
			node, ok := record.Get("s")
			if !ok {
				continue
			}

			site, err := r.nodeToSite(node.(neo4j.Node))
			if err != nil {
				return nil, err
			}

			sites = append(sites, site)
		}

		if err := result.Err(); err != nil {
			return nil, err
		}

		return sites, nil
	})

	if err != nil {
		return nil, err
	}

	return result.([]*domain.Site), nil
}

// nodeToSite converts a Neo4j node to a Site domain object
func (r *GraphSiteRepository) nodeToSite(node neo4j.Node) (*domain.Site, error) {
	props := node.Props

	site := &domain.Site{
		ID:                  props["id"].(string),
		Name:                getStringProp(props, "name"),
		OwnerOrganizationID: getStringProp(props, "owner_organization_id"),
		EnergyRating:        getStringProp(props, "energy_rating"),
		EnvironmentalImpact: getStringProp(props, "environmental_impact"),
		YearBuilt:           getStringProp(props, "year_built"),
		BuilderOwner:        getStringProp(props, "builder_owner"),
		Architect:           getStringProp(props, "architect"),
		OriginalPurpose:     getStringProp(props, "original_purpose"),
		CurrentUse:          getStringProp(props, "current_use"),
		Style:               getStringProp(props, "style"),
		Materials:           getStringProp(props, "materials"),
		HeritageStatus:      getStringProp(props, "heritage_status"),
		Notes:               getStringProp(props, "notes"),
	}

	// Parse enum fields
	if siteTypeStr, ok := props["site_type"].(string); ok {
		site.SiteType = domain.SiteType(siteTypeStr)
	}
	if ownershipStr, ok := props["ownership"].(string); ok {
		site.Ownership = domain.Ownership(ownershipStr)
	}

	// Parse numeric fields
	if val, ok := props["floor_area_m2"].(float64); ok {
		site.FloorAreaM2 = val
	}
	if val, ok := props["latitude"].(float64); ok {
		site.Latitude = val
	}
	if val, ok := props["longitude"].(float64); ok {
		site.Longitude = val
	}
	if val, ok := props["parking_spaces"].(int64); ok {
		site.ParkingSpaces = int(val)
	}
	if val, ok := props["loading_docks"].(int64); ok {
		site.LoadingDocks = int(val)
	}
	if val, ok := props["crane_capacity_tonnes"].(float64); ok {
		site.CraneCapacityTonnes = val
	}
	if val, ok := props["storeys"].(int64); ok {
		site.Storeys = int(val)
	}

	// Parse timestamps
	if createdAt, ok := props["created_at"].(string); ok {
		if t, err := time.Parse(time.RFC3339, createdAt); err == nil {
			site.CreatedAt = t
		}
	}
	if updatedAt, ok := props["updated_at"].(string); ok {
		if t, err := time.Parse(time.RFC3339, updatedAt); err == nil {
			site.UpdatedAt = t
		}
	}

	return site, nil
}