package iace

import (
	"encoding/json"
	"time"

	"github.com/google/uuid"
)

// ============================================================================
// Constants / Enums
// ============================================================================

// ProjectStatus represents the lifecycle status of an IACE project
type ProjectStatus string

const (
	ProjectStatusDraft          ProjectStatus = "draft"
	ProjectStatusOnboarding     ProjectStatus = "onboarding"
	ProjectStatusClassification ProjectStatus = "classification"
	ProjectStatusHazardAnalysis ProjectStatus = "hazard_analysis"
	ProjectStatusMitigation     ProjectStatus = "mitigation"
	ProjectStatusVerification   ProjectStatus = "verification"
	ProjectStatusTechFile       ProjectStatus = "tech_file"
	ProjectStatusCompleted      ProjectStatus = "completed"
	ProjectStatusArchived       ProjectStatus = "archived"
)

// ComponentType represents the type of a system component
type ComponentType string

const (
	ComponentTypeSoftware   ComponentType = "software"
	ComponentTypeFirmware   ComponentType = "firmware"
	ComponentTypeAIModel    ComponentType = "ai_model"
	ComponentTypeHMI        ComponentType = "hmi"
	ComponentTypeSensor     ComponentType = "sensor"
	ComponentTypeActuator   ComponentType = "actuator"
	ComponentTypeController ComponentType = "controller"
	ComponentTypeNetwork    ComponentType = "network"
	ComponentTypeOther      ComponentType = "other"
)

// RegulationType represents the applicable EU regulation
type RegulationType string

const (
	RegulationNIS2                RegulationType = "nis2"
	RegulationAIAct               RegulationType = "ai_act"
	RegulationCRA                 RegulationType = "cra"
	RegulationMachineryRegulation RegulationType = "machinery_regulation"
)

// HazardStatus represents the lifecycle status of a hazard
type HazardStatus string

const (
	HazardStatusIdentified HazardStatus = "identified"
	HazardStatusAssessed   HazardStatus = "assessed"
	HazardStatusMitigated  HazardStatus = "mitigated"
	HazardStatusAccepted   HazardStatus = "accepted"
	HazardStatusClosed     HazardStatus = "closed"
)

// AssessmentType represents the type of risk assessment
type AssessmentType string

const (
	AssessmentTypeInitial        AssessmentType = "initial"
	AssessmentTypePostMitigation AssessmentType = "post_mitigation"
	AssessmentTypeReassessment   AssessmentType = "reassessment"
)

// RiskLevel represents the severity level of a risk
type RiskLevel string

const (
	RiskLevelCritical   RiskLevel = "critical"
	RiskLevelHigh       RiskLevel = "high"
	RiskLevelMedium     RiskLevel = "medium"
	RiskLevelLow        RiskLevel = "low"
	RiskLevelNegligible RiskLevel = "negligible"
)

// ReductionType represents the type of risk reduction measure
type ReductionType string

const (
	ReductionTypeDesign      ReductionType = "design"
	ReductionTypeProtective  ReductionType = "protective"
	ReductionTypeInformation ReductionType = "information"
)

// MitigationStatus represents the lifecycle status of a mitigation measure
type MitigationStatus string

const (
	MitigationStatusPlanned     MitigationStatus = "planned"
	MitigationStatusImplemented MitigationStatus = "implemented"
	MitigationStatusVerified    MitigationStatus = "verified"
	MitigationStatusRejected    MitigationStatus = "rejected"
)

// VerificationMethod represents the method used for verification
type VerificationMethod string

const (
	VerificationMethodTest       VerificationMethod = "test"
	VerificationMethodAnalysis   VerificationMethod = "analysis"
	VerificationMethodInspection VerificationMethod = "inspection"
	VerificationMethodReview     VerificationMethod = "review"
)

// TechFileSectionStatus represents the status of a technical file section
type TechFileSectionStatus string

const (
	TechFileSectionStatusDraft     TechFileSectionStatus = "draft"
	TechFileSectionStatusGenerated TechFileSectionStatus = "generated"
	TechFileSectionStatusReviewed  TechFileSectionStatus = "reviewed"
	TechFileSectionStatusApproved  TechFileSectionStatus = "approved"
)

// MonitoringEventType represents the type of monitoring event
type MonitoringEventType string

const (
	MonitoringEventTypeIncident        MonitoringEventType = "incident"
	MonitoringEventTypeUpdate          MonitoringEventType = "update"
	MonitoringEventTypeDriftAlert      MonitoringEventType = "drift_alert"
	MonitoringEventTypeRegulationChange MonitoringEventType = "regulation_change"
	MonitoringEventTypeAudit           MonitoringEventType = "audit"
)

// AuditAction represents the type of action recorded in the audit trail
type AuditAction string

const (
	AuditActionCreate  AuditAction = "create"
	AuditActionUpdate  AuditAction = "update"
	AuditActionDelete  AuditAction = "delete"
	AuditActionApprove AuditAction = "approve"
	AuditActionVerify  AuditAction = "verify"
)

// ============================================================================
// Main Entities
// ============================================================================

// Project represents an IACE compliance project for a machine or system
type Project struct {
	ID                   uuid.UUID        `json:"id"`
	TenantID             uuid.UUID        `json:"tenant_id"`
	MachineName          string           `json:"machine_name"`
	MachineType          string           `json:"machine_type"`
	Manufacturer         string           `json:"manufacturer"`
	Description          string           `json:"description,omitempty"`
	NarrativeText        string           `json:"narrative_text,omitempty"`
	Status               ProjectStatus    `json:"status"`
	CEMarkingTarget      string           `json:"ce_marking_target,omitempty"`
	CompletenessScore    float64          `json:"completeness_score"`
	RiskSummary          map[string]int   `json:"risk_summary,omitempty"`
	TriggeredRegulations json.RawMessage  `json:"triggered_regulations,omitempty"`
	Metadata             json.RawMessage  `json:"metadata,omitempty"`
	CreatedAt            time.Time        `json:"created_at"`
	UpdatedAt            time.Time        `json:"updated_at"`
	ArchivedAt           *time.Time       `json:"archived_at,omitempty"`
}

// Component represents a system component within a project
type Component struct {
	ID                uuid.UUID       `json:"id"`
	ProjectID         uuid.UUID       `json:"project_id"`
	ParentID          *uuid.UUID      `json:"parent_id,omitempty"`
	Name              string          `json:"name"`
	ComponentType     ComponentType   `json:"component_type"`
	Version           string          `json:"version,omitempty"`
	Description       string          `json:"description,omitempty"`
	IsSafetyRelevant  bool            `json:"is_safety_relevant"`
	IsNetworked       bool            `json:"is_networked"`
	Metadata          json.RawMessage `json:"metadata,omitempty"`
	SortOrder         int             `json:"sort_order"`
	CreatedAt         time.Time       `json:"created_at"`
	UpdatedAt         time.Time       `json:"updated_at"`
}

// RegulatoryClassification represents the classification result for a regulation
type RegulatoryClassification struct {
	ID                   uuid.UUID       `json:"id"`
	ProjectID            uuid.UUID       `json:"project_id"`
	Regulation           RegulationType  `json:"regulation"`
	ClassificationResult string          `json:"classification_result"`
	RiskLevel            RiskLevel       `json:"risk_level"`
	Confidence           float64         `json:"confidence"`
	Reasoning            string          `json:"reasoning,omitempty"`
	RAGSources           json.RawMessage `json:"rag_sources,omitempty"`
	Requirements         json.RawMessage `json:"requirements,omitempty"`
	CreatedAt            time.Time       `json:"created_at"`
	UpdatedAt            time.Time       `json:"updated_at"`
}

// HazardLibraryEntry represents a reusable hazard template from the library
type HazardLibraryEntry struct {
	ID                       uuid.UUID       `json:"id"`
	Category                 string          `json:"category"`
	Name                     string          `json:"name"`
	Description              string          `json:"description,omitempty"`
	DefaultSeverity          int             `json:"default_severity"`
	DefaultProbability       int             `json:"default_probability"`
	ApplicableComponentTypes []string        `json:"applicable_component_types"`
	RegulationReferences     []string        `json:"regulation_references"`
	SuggestedMitigations     json.RawMessage `json:"suggested_mitigations,omitempty"`
	IsBuiltin                bool            `json:"is_builtin"`
	TenantID                 *uuid.UUID      `json:"tenant_id,omitempty"`
	CreatedAt                time.Time       `json:"created_at"`
}

// Hazard represents a specific hazard identified within a project
type Hazard struct {
	ID              uuid.UUID    `json:"id"`
	ProjectID       uuid.UUID    `json:"project_id"`
	ComponentID     uuid.UUID    `json:"component_id"`
	LibraryHazardID *uuid.UUID   `json:"library_hazard_id,omitempty"`
	Name            string       `json:"name"`
	Description     string       `json:"description,omitempty"`
	Scenario        string       `json:"scenario,omitempty"`
	Category        string       `json:"category"`
	Status          HazardStatus `json:"status"`
	CreatedAt       time.Time    `json:"created_at"`
	UpdatedAt       time.Time    `json:"updated_at"`
}

// RiskAssessment represents a quantitative risk assessment for a hazard
type RiskAssessment struct {
	ID                      uuid.UUID      `json:"id"`
	HazardID                uuid.UUID      `json:"hazard_id"`
	Version                 int            `json:"version"`
	AssessmentType          AssessmentType `json:"assessment_type"`
	Severity                int            `json:"severity"`
	Exposure                int            `json:"exposure"`
	Probability             int            `json:"probability"`
	Avoidance               int            `json:"avoidance,omitempty"` // 0=disabled, 1-5 (3=neutral)
	InherentRisk            float64        `json:"inherent_risk"`
	ControlMaturity         int            `json:"control_maturity"`
	ControlCoverage         float64        `json:"control_coverage"`
	TestEvidenceStrength    float64        `json:"test_evidence_strength"`
	CEff                    float64        `json:"c_eff"`
	ResidualRisk            float64        `json:"residual_risk"`
	RiskLevel               RiskLevel      `json:"risk_level"`
	IsAcceptable            bool           `json:"is_acceptable"`
	AcceptanceJustification string         `json:"acceptance_justification,omitempty"`
	AssessedBy              uuid.UUID      `json:"assessed_by"`
	CreatedAt               time.Time      `json:"created_at"`
}

// Mitigation represents a risk reduction measure applied to a hazard
type Mitigation struct {
	ID                 uuid.UUID          `json:"id"`
	HazardID           uuid.UUID          `json:"hazard_id"`
	ReductionType      ReductionType      `json:"reduction_type"`
	Name               string             `json:"name"`
	Description        string             `json:"description,omitempty"`
	Status             MitigationStatus   `json:"status"`
	VerificationMethod VerificationMethod `json:"verification_method,omitempty"`
	VerificationResult string             `json:"verification_result,omitempty"`
	VerifiedAt         *time.Time         `json:"verified_at,omitempty"`
	VerifiedBy         uuid.UUID          `json:"verified_by,omitempty"`
	CreatedAt          time.Time          `json:"created_at"`
	UpdatedAt          time.Time          `json:"updated_at"`
}

// Evidence represents an uploaded file that serves as evidence for compliance
type Evidence struct {
	ID                 uuid.UUID  `json:"id"`
	ProjectID          uuid.UUID  `json:"project_id"`
	MitigationID       *uuid.UUID `json:"mitigation_id,omitempty"`
	VerificationPlanID *uuid.UUID `json:"verification_plan_id,omitempty"`
	FileName           string     `json:"file_name"`
	FilePath           string     `json:"file_path"`
	FileHash           string     `json:"file_hash"`
	FileSize           int64      `json:"file_size"`
	MimeType           string     `json:"mime_type"`
	Description        string     `json:"description,omitempty"`
	UploadedBy         uuid.UUID  `json:"uploaded_by"`
	CreatedAt          time.Time  `json:"created_at"`
}

// VerificationPlan represents a plan for verifying compliance measures
type VerificationPlan struct {
	ID                 uuid.UUID          `json:"id"`
	ProjectID          uuid.UUID          `json:"project_id"`
	HazardID           *uuid.UUID         `json:"hazard_id,omitempty"`
	MitigationID       *uuid.UUID         `json:"mitigation_id,omitempty"`
	Title              string             `json:"title"`
	Description        string             `json:"description,omitempty"`
	AcceptanceCriteria string             `json:"acceptance_criteria,omitempty"`
	Method             VerificationMethod `json:"method"`
	Status             string             `json:"status"`
	Result             string             `json:"result,omitempty"`
	CompletedAt        *time.Time         `json:"completed_at,omitempty"`
	CompletedBy        uuid.UUID          `json:"completed_by,omitempty"`
	CreatedAt          time.Time          `json:"created_at"`
	UpdatedAt          time.Time          `json:"updated_at"`
}

// TechFileSection represents a section of the technical documentation file
type TechFileSection struct {
	ID          uuid.UUID             `json:"id"`
	ProjectID   uuid.UUID             `json:"project_id"`
	SectionType string                `json:"section_type"`
	Title       string                `json:"title"`
	Content     string                `json:"content,omitempty"`
	Version     int                   `json:"version"`
	Status      TechFileSectionStatus `json:"status"`
	ApprovedBy  uuid.UUID             `json:"approved_by,omitempty"`
	ApprovedAt  *time.Time            `json:"approved_at,omitempty"`
	Metadata    json.RawMessage       `json:"metadata,omitempty"`
	CreatedAt   time.Time             `json:"created_at"`
	UpdatedAt   time.Time             `json:"updated_at"`
}

// MonitoringEvent represents a post-market monitoring event
type MonitoringEvent struct {
	ID               uuid.UUID           `json:"id"`
	ProjectID        uuid.UUID           `json:"project_id"`
	EventType        MonitoringEventType `json:"event_type"`
	Title            string              `json:"title"`
	Description      string              `json:"description,omitempty"`
	Severity         string              `json:"severity"`
	ImpactAssessment string              `json:"impact_assessment,omitempty"`
	Status           string              `json:"status"`
	ResolvedAt       *time.Time          `json:"resolved_at,omitempty"`
	ResolvedBy       uuid.UUID           `json:"resolved_by,omitempty"`
	Metadata         json.RawMessage     `json:"metadata,omitempty"`
	CreatedAt        time.Time           `json:"created_at"`
	UpdatedAt        time.Time           `json:"updated_at"`
}

// AuditTrailEntry represents an immutable audit log entry for compliance traceability
type AuditTrailEntry struct {
	ID         uuid.UUID       `json:"id"`
	ProjectID  uuid.UUID       `json:"project_id"`
	EntityType string          `json:"entity_type"`
	EntityID   uuid.UUID       `json:"entity_id"`
	Action     AuditAction     `json:"action"`
	UserID     uuid.UUID       `json:"user_id"`
	OldValues  json.RawMessage `json:"old_values,omitempty"`
	NewValues  json.RawMessage `json:"new_values,omitempty"`
	Hash       string          `json:"hash"`
	CreatedAt  time.Time       `json:"created_at"`
}

// ============================================================================
// API Request Types
// ============================================================================

// CreateProjectRequest is the API request for creating a new IACE project
type CreateProjectRequest struct {
	MachineName     string          `json:"machine_name" binding:"required"`
	MachineType     string          `json:"machine_type" binding:"required"`
	Manufacturer    string          `json:"manufacturer" binding:"required"`
	Description     string          `json:"description,omitempty"`
	NarrativeText   string          `json:"narrative_text,omitempty"`
	CEMarkingTarget string          `json:"ce_marking_target,omitempty"`
	Metadata        json.RawMessage `json:"metadata,omitempty"`
}

// UpdateProjectRequest is the API request for updating an existing project
type UpdateProjectRequest struct {
	MachineName     *string          `json:"machine_name,omitempty"`
	MachineType     *string          `json:"machine_type,omitempty"`
	Manufacturer    *string          `json:"manufacturer,omitempty"`
	Description     *string          `json:"description,omitempty"`
	NarrativeText   *string          `json:"narrative_text,omitempty"`
	CEMarkingTarget *string          `json:"ce_marking_target,omitempty"`
	Metadata        *json.RawMessage `json:"metadata,omitempty"`
}

// CreateComponentRequest is the API request for adding a component to a project
type CreateComponentRequest struct {
	ProjectID        uuid.UUID     `json:"project_id" binding:"required"`
	ParentID         *uuid.UUID    `json:"parent_id,omitempty"`
	Name             string        `json:"name" binding:"required"`
	ComponentType    ComponentType `json:"component_type" binding:"required"`
	Version          string        `json:"version,omitempty"`
	Description      string        `json:"description,omitempty"`
	IsSafetyRelevant bool          `json:"is_safety_relevant"`
	IsNetworked      bool          `json:"is_networked"`
}

// CreateHazardRequest is the API request for creating a new hazard
type CreateHazardRequest struct {
	ProjectID       uuid.UUID  `json:"project_id" binding:"required"`
	ComponentID     uuid.UUID  `json:"component_id" binding:"required"`
	LibraryHazardID *uuid.UUID `json:"library_hazard_id,omitempty"`
	Name            string     `json:"name" binding:"required"`
	Description     string     `json:"description,omitempty"`
	Scenario        string     `json:"scenario,omitempty"`
	Category        string     `json:"category" binding:"required"`
}

// AssessRiskRequest is the API request for performing a risk assessment
type AssessRiskRequest struct {
	HazardID                uuid.UUID `json:"hazard_id" binding:"required"`
	Severity                int       `json:"severity" binding:"required"`
	Exposure                int       `json:"exposure" binding:"required"`
	Probability             int       `json:"probability" binding:"required"`
	Avoidance               int       `json:"avoidance,omitempty"`           // 0=disabled, 1-5 (3=neutral)
	ControlMaturity         int       `json:"control_maturity" binding:"required"`
	ControlCoverage         float64   `json:"control_coverage" binding:"required"`
	TestEvidenceStrength    float64   `json:"test_evidence_strength" binding:"required"`
	AcceptanceJustification string    `json:"acceptance_justification,omitempty"`
}

// CreateMitigationRequest is the API request for creating a mitigation measure
type CreateMitigationRequest struct {
	HazardID      uuid.UUID     `json:"hazard_id" binding:"required"`
	ReductionType ReductionType `json:"reduction_type" binding:"required"`
	Name          string        `json:"name" binding:"required"`
	Description   string        `json:"description,omitempty"`
}

// CreateVerificationPlanRequest is the API request for creating a verification plan
type CreateVerificationPlanRequest struct {
	ProjectID          uuid.UUID          `json:"project_id" binding:"required"`
	HazardID           *uuid.UUID         `json:"hazard_id,omitempty"`
	MitigationID       *uuid.UUID         `json:"mitigation_id,omitempty"`
	Title              string             `json:"title" binding:"required"`
	Description        string             `json:"description,omitempty"`
	AcceptanceCriteria string             `json:"acceptance_criteria,omitempty"`
	Method             VerificationMethod `json:"method" binding:"required"`
}

// CreateMonitoringEventRequest is the API request for logging a monitoring event
type CreateMonitoringEventRequest struct {
	ProjectID   uuid.UUID           `json:"project_id" binding:"required"`
	EventType   MonitoringEventType `json:"event_type" binding:"required"`
	Title       string              `json:"title" binding:"required"`
	Description string              `json:"description,omitempty"`
	Severity    string              `json:"severity" binding:"required"`
}

// InitFromProfileRequest is the API request for initializing a project from a company profile
type InitFromProfileRequest struct {
	CompanyProfile  json.RawMessage `json:"company_profile" binding:"required"`
	ComplianceScope json.RawMessage `json:"compliance_scope" binding:"required"`
}

// ============================================================================
// API Response Types
// ============================================================================

// ProjectListResponse is the API response for listing projects
type ProjectListResponse struct {
	Projects []Project `json:"projects"`
	Total    int       `json:"total"`
}

// ProjectDetailResponse is the API response for a single project with related entities
type ProjectDetailResponse struct {
	Project
	Components      []Component               `json:"components"`
	Classifications []RegulatoryClassification `json:"classifications"`
	CompletenessGates []CompletenessGate       `json:"completeness_gates"`
}

// RiskSummaryResponse is the API response for an aggregated risk overview
type RiskSummaryResponse struct {
	TotalHazards     int       `json:"total_hazards"`
	Critical         int       `json:"critical"`
	High             int       `json:"high"`
	Medium           int       `json:"medium"`
	Low              int       `json:"low"`
	Negligible       int       `json:"negligible"`
	OverallRiskLevel RiskLevel `json:"overall_risk_level"`
	AllAcceptable    bool      `json:"all_acceptable"`
}

// CompletenessGate represents a single gate in the project completeness checklist
type CompletenessGate struct {
	ID       string `json:"id"`
	Category string `json:"category"`
	Label    string `json:"label"`
	Required bool   `json:"required"`
	Passed   bool   `json:"passed"`
	Details  string `json:"details,omitempty"`
}