package transport

import (
	"fmt"
)

// SymbiosisType represents different types of industrial symbiosis exchanges
type SymbiosisType string

const (
	// Resource Exchange Symbioses
	SymbiosisWasteToResource   SymbiosisType = "waste_to_resource"
	SymbiosisUtilitySharing    SymbiosisType = "utility_sharing"
	SymbiosisEnergyCascading   SymbiosisType = "energy_cascading"
	SymbiosisMaterialRecycling SymbiosisType = "material_recycling"

	// Infrastructure Sharing Symbioses
	SymbiosisPhysicalInfra    SymbiosisType = "physical_infrastructure"
	SymbiosisEquipmentSharing SymbiosisType = "equipment_sharing"
	SymbiosisLogisticsNetwork SymbiosisType = "logistics_network"
	SymbiosisUtilityInfra     SymbiosisType = "utility_infrastructure"

	// Service-Based Symbioses
	SymbiosisKnowledgeSharing SymbiosisType = "knowledge_sharing"
	SymbiosisWorkforceSharing SymbiosisType = "workforce_sharing"
	SymbiosisMaintenanceSvc   SymbiosisType = "maintenance_services"
	SymbiosisProcurement      SymbiosisType = "procurement_cooperative"

	// Digital Symbioses
	SymbiosisDataSharing      SymbiosisType = "data_sharing"
	SymbiosisPlatformCoop     SymbiosisType = "platform_cooperative"
	SymbiosisIoTNetwork       SymbiosisType = "iot_network_sharing"
	SymbiosisSoftwareLicenses SymbiosisType = "software_licenses"
)

// ExchangeParams contains parameters for symbiosis exchange cost calculations
type ExchangeParams struct {
	DistanceKm     float64       `json:"distance_km"`     // Distance in kilometers (for physical exchanges)
	Value          float64       `json:"value"`           // Exchange value (€)
	Volume         float64       `json:"volume"`          // Exchange volume (units)
	SymbiosisType  SymbiosisType `json:"symbiosis_type"`  // Type of symbiosis exchange
	Complexity     string        `json:"complexity"`      // "low", "medium", "high" implementation complexity
	RiskLevel      string        `json:"risk_level"`      // "low", "medium", "high" risk level
	OperatingHours int           `json:"operating_hours"` // Annual operating hours (default: 8000)
}

// ExchangeCost represents the cost breakdown for enabling a symbiosis exchange
type ExchangeCost struct {
	CapitalCost        float64 `json:"capital_cost"`         // One-time setup cost (€)
	AnnualOpexCost     float64 `json:"annual_opex_cost"`     // Annual operating cost (€)
	PlatformFee        float64 `json:"platform_fee"`         // Platform transaction fee (€)
	RegulatoryCost     float64 `json:"regulatory_cost"`      // Compliance/regulatory cost (€)
	RiskMitigationCost float64 `json:"risk_mitigation_cost"` // Insurance/liability cost (€)
	TotalAnnualCost    float64 `json:"total_annual_cost"`    // Total annual cost (€)
	CostPerUnit        float64 `json:"cost_per_unit"`        // Cost per unit exchanged
	Feasibility        string  `json:"feasibility"`          // "low", "medium", "high"
	ROIYears           float64 `json:"roi_years"`            // Years to ROI
}

// DefaultExchangeParams returns sensible defaults for exchange calculations
func DefaultExchangeParams() ExchangeParams {
	return ExchangeParams{
		OperatingHours: 8000, // 8000 hours/year = ~90% uptime
		Complexity:     "medium",
		RiskLevel:      "medium",
	}
}

// CalculateExchangeCost calculates total costs for enabling a symbiosis exchange
func CalculateExchangeCost(params ExchangeParams) (ExchangeCost, error) {
	// Validate parameters first
	if err := ValidateExchangeParams(params); err != nil {
		return ExchangeCost{}, err
	}

	// Calculate base costs based on symbiosis type
	baseCosts, err := calculateBaseExchangeCosts(params)
	if err != nil {
		return ExchangeCost{}, err
	}

	// Add complexity multiplier
	complexityMultiplier := getComplexityMultiplier(params.Complexity)

	// Add risk mitigation costs
	riskCost := calculateRiskMitigationCost(params.Value, params.RiskLevel)

	// Platform fee (percentage of transaction value)
	platformFee := params.Value * 0.05 // 5% platform fee

	// Regulatory compliance cost
	regulatoryCost := calculateRegulatoryCost(params.SymbiosisType, params.Value)

	// Total annual costs
	totalAnnual := (baseCosts.AnnualOpexCost + riskCost + regulatoryCost) * complexityMultiplier
	totalCapital := baseCosts.CapitalCost * complexityMultiplier

	// Cost per unit exchanged
	costPerUnit := 0.0
	if params.Volume > 0 {
		costPerUnit = totalAnnual / params.Volume
	}

	// ROI calculation (simple payback period)
	annualBenefit := params.Value * 0.15 // Assume 15% annual benefit from exchange
	roiYears := totalCapital / (annualBenefit - totalAnnual)
	if roiYears < 0 {
		roiYears = 999 // Never reaches ROI
	}

	feasibility := assessExchangeFeasibility(params)

	return ExchangeCost{
		CapitalCost:        totalCapital,
		AnnualOpexCost:     baseCosts.AnnualOpexCost * complexityMultiplier,
		PlatformFee:        platformFee,
		RegulatoryCost:     regulatoryCost,
		RiskMitigationCost: riskCost,
		TotalAnnualCost:    totalAnnual,
		CostPerUnit:        costPerUnit,
		Feasibility:        feasibility,
		ROIYears:           roiYears,
	}, nil
}

// calculateBaseExchangeCosts calculates costs based on symbiosis type
func calculateBaseExchangeCosts(params ExchangeParams) (ExchangeCost, error) {
	switch params.SymbiosisType {
	case SymbiosisWasteToResource, SymbiosisUtilitySharing, SymbiosisEnergyCascading, SymbiosisMaterialRecycling:
		return calculateResourceExchangeCosts(params)
	case SymbiosisPhysicalInfra, SymbiosisEquipmentSharing, SymbiosisLogisticsNetwork, SymbiosisUtilityInfra:
		return calculateInfrastructureSharingCosts(params)
	case SymbiosisKnowledgeSharing, SymbiosisWorkforceSharing, SymbiosisMaintenanceSvc, SymbiosisProcurement:
		return calculateServiceExchangeCosts(params)
	case SymbiosisDataSharing, SymbiosisPlatformCoop, SymbiosisIoTNetwork, SymbiosisSoftwareLicenses:
		return calculateDigitalExchangeCosts(params)
	default:
		return ExchangeCost{}, fmt.Errorf("unsupported symbiosis type: %s", params.SymbiosisType)
	}
}

// calculateResourceExchangeCosts handles physical resource exchanges (waste, utilities, energy, materials)
func calculateResourceExchangeCosts(params ExchangeParams) (ExchangeCost, error) {
	// Base costs depend on resource type and physical transport needs
	var capitalCost, annualOpex float64

	switch params.SymbiosisType {
	case SymbiosisWasteToResource, SymbiosisMaterialRecycling:
		// Material transport costs
		capitalCost = 50000.0 + (50.0 * params.DistanceKm) // Collection/processing equipment
		annualOpex = params.Volume * 0.10                  // €0.10 per unit for handling/transport
	case SymbiosisUtilitySharing, SymbiosisEnergyCascading:
		// Energy/utility sharing costs
		capitalCost = 25000.0 + (25.0 * params.DistanceKm) // Connection infrastructure
		annualOpex = params.Value * 0.03                   // 3% of exchange value for maintenance
	}

	return ExchangeCost{
		CapitalCost:    capitalCost,
		AnnualOpexCost: annualOpex,
	}, nil
}

// calculateInfrastructureSharingCosts handles shared physical infrastructure
func calculateInfrastructureSharingCosts(params ExchangeParams) (ExchangeCost, error) {
	// Infrastructure sharing has lower costs as assets already exist
	capitalCost := params.Value * 0.05 // 5% of value for integration/setup
	annualOpex := params.Value * 0.02  // 2% of value for coordination/maintenance

	return ExchangeCost{
		CapitalCost:    capitalCost,
		AnnualOpexCost: annualOpex,
	}, nil
}

// calculateServiceExchangeCosts handles knowledge, workforce, maintenance, procurement exchanges
func calculateServiceExchangeCosts(params ExchangeParams) (ExchangeCost, error) {
	// Service exchanges are primarily about coordination and expertise
	capitalCost := 10000.0            // Training/coordination setup
	annualOpex := params.Value * 0.08 // 8% for ongoing coordination and quality assurance

	return ExchangeCost{
		CapitalCost:    capitalCost,
		AnnualOpexCost: annualOpex,
	}, nil
}

// calculateDigitalExchangeCosts handles data, IoT, software, platform exchanges
func calculateDigitalExchangeCosts(params ExchangeParams) (ExchangeCost, error) {
	// Digital exchanges have minimal physical costs, focus on integration
	capitalCost := 5000.0             // API integration, security setup
	annualOpex := params.Value * 0.04 // 4% for data management and security

	return ExchangeCost{
		CapitalCost:    capitalCost,
		AnnualOpexCost: annualOpex,
	}, nil
}

// getComplexityMultiplier returns cost multiplier based on implementation complexity
func getComplexityMultiplier(complexity string) float64 {
	switch complexity {
	case "low":
		return 1.0
	case "medium":
		return 1.3
	case "high":
		return 1.8
	default:
		return 1.3 // Default to medium
	}
}

// calculateRiskMitigationCost calculates insurance and liability costs
func calculateRiskMitigationCost(value float64, riskLevel string) float64 {
	var baseRate float64
	switch riskLevel {
	case "low":
		baseRate = 0.01 // 1% of value
	case "medium":
		baseRate = 0.025 // 2.5% of value
	case "high":
		baseRate = 0.05 // 5% of value
	default:
		baseRate = 0.025
	}
	return value * baseRate
}

// calculateRegulatoryCost calculates compliance and regulatory costs
func calculateRegulatoryCost(symbiosisType SymbiosisType, value float64) float64 {
	var baseRate float64

	// Different regulatory requirements by symbiosis type
	switch symbiosisType {
	case SymbiosisWasteToResource, SymbiosisMaterialRecycling:
		baseRate = 0.03 // 3% - high regulatory burden for waste/material handling
	case SymbiosisEnergyCascading, SymbiosisUtilitySharing:
		baseRate = 0.02 // 2% - moderate regulatory burden for energy/utilities
	case SymbiosisPhysicalInfra, SymbiosisEquipmentSharing:
		baseRate = 0.015 // 1.5% - infrastructure sharing regulations
	case SymbiosisKnowledgeSharing, SymbiosisWorkforceSharing:
		baseRate = 0.01 // 1% - lighter regulations for service exchanges
	case SymbiosisDataSharing, SymbiosisIoTNetwork, SymbiosisSoftwareLicenses:
		baseRate = 0.0005 // 0.05% - data protection and IP regulations
	default:
		baseRate = 0.02 // Default 2%
	}

	return value * baseRate
}

// assessExchangeFeasibility evaluates overall feasibility of the symbiosis exchange
func assessExchangeFeasibility(params ExchangeParams) string {
	score := 0.0

	// Distance factor (closer = better)
	if params.DistanceKm <= 1.0 {
		score += 1.0
	} else if params.DistanceKm <= 5.0 {
		score += 0.7
	} else if params.DistanceKm <= 25.0 {
		score += 0.4
	} else {
		score += 0.1
	}

	// Complexity factor (lower = better)
	switch params.Complexity {
	case "low":
		score += 1.0
	case "medium":
		score += 0.6
	case "high":
		score += 0.3
	}

	// Risk factor (lower = better)
	switch params.RiskLevel {
	case "low":
		score += 1.0
	case "medium":
		score += 0.6
	case "high":
		score += 0.3
	}

	// Symbiosis type factor (some types are naturally easier)
	switch params.SymbiosisType {
	case SymbiosisDataSharing, SymbiosisSoftwareLicenses:
		score += 0.8 // Digital exchanges are easier
	case SymbiosisKnowledgeSharing, SymbiosisWorkforceSharing:
		score += 0.6 // Service exchanges are moderately easy
	case SymbiosisWasteToResource, SymbiosisMaterialRecycling:
		score += 0.4 // Physical material exchanges are challenging
	default:
		score += 0.5
	}

	// Normalize score to 0-1 and convert to feasibility level
	normalizedScore := score / 4.0 // Max possible score is 4.0

	if normalizedScore >= 0.7 {
		return "high"
	} else if normalizedScore >= 0.4 {
		return "medium"
	}
	return "low"
}

// ValidateExchangeParams checks if exchange parameters are valid
func ValidateExchangeParams(params ExchangeParams) error {
	if params.Value < 0 {
		return fmt.Errorf("exchange value cannot be negative")
	}
	if params.Volume < 0 {
		return fmt.Errorf("exchange volume cannot be negative")
	}
	if params.DistanceKm < 0 {
		return fmt.Errorf("distance cannot be negative")
	}
	if params.SymbiosisType == "" {
		return fmt.Errorf("symbiosis type is required")
	}
	if params.OperatingHours <= 0 {
		params.OperatingHours = 8000 // Default
	}
	return nil
}