package vendor

import (
	"encoding/json"
	"time"

	"github.com/google/uuid"
)

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

// VendorRole represents the GDPR role of a vendor in data processing
type VendorRole string

const (
	VendorRoleProcessor       VendorRole = "PROCESSOR"
	VendorRoleController      VendorRole = "CONTROLLER"
	VendorRoleJointController VendorRole = "JOINT_CONTROLLER"
	VendorRoleSubProcessor    VendorRole = "SUB_PROCESSOR"
	VendorRoleThirdParty      VendorRole = "THIRD_PARTY"
)

// VendorStatus represents the lifecycle status of a vendor
type VendorStatus string

const (
	VendorStatusActive        VendorStatus = "ACTIVE"
	VendorStatusInactive      VendorStatus = "INACTIVE"
	VendorStatusPendingReview VendorStatus = "PENDING_REVIEW"
	VendorStatusTerminated    VendorStatus = "TERMINATED"
)

// DocumentType represents the type of a contract/compliance document
type DocumentType string

const (
	DocumentTypeAVV              DocumentType = "AVV"
	DocumentTypeMSA              DocumentType = "MSA"
	DocumentTypeSLA              DocumentType = "SLA"
	DocumentTypeSCC              DocumentType = "SCC"
	DocumentTypeNDA              DocumentType = "NDA"
	DocumentTypeTOMAnnex         DocumentType = "TOM_ANNEX"
	DocumentTypeCertification    DocumentType = "CERTIFICATION"
	DocumentTypeSubProcessorList DocumentType = "SUB_PROCESSOR_LIST"
)

// FindingType represents the type of a compliance finding
type FindingType string

const (
	FindingTypeOK      FindingType = "OK"
	FindingTypeGap     FindingType = "GAP"
	FindingTypeRisk    FindingType = "RISK"
	FindingTypeUnknown FindingType = "UNKNOWN"
)

// FindingStatus represents the resolution status of a finding
type FindingStatus string

const (
	FindingStatusOpen          FindingStatus = "OPEN"
	FindingStatusInProgress    FindingStatus = "IN_PROGRESS"
	FindingStatusResolved      FindingStatus = "RESOLVED"
	FindingStatusAccepted      FindingStatus = "ACCEPTED"
	FindingStatusFalsePositive FindingStatus = "FALSE_POSITIVE"
)

// ControlStatus represents the assessment status of a control instance
type ControlStatus string

const (
	ControlStatusPass          ControlStatus = "PASS"
	ControlStatusPartial       ControlStatus = "PARTIAL"
	ControlStatusFail          ControlStatus = "FAIL"
	ControlStatusNotApplicable ControlStatus = "NOT_APPLICABLE"
	ControlStatusPlanned       ControlStatus = "PLANNED"
)

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

// Vendor represents a third-party vendor/service provider subject to GDPR compliance
type Vendor struct {
	ID       uuid.UUID `json:"id" db:"id"`
	TenantID uuid.UUID `json:"tenant_id" db:"tenant_id"`

	// Basic info
	Name      string `json:"name" db:"name"`
	LegalForm string `json:"legal_form,omitempty" db:"legal_form"`
	Country   string `json:"country" db:"country"`
	Address   json.RawMessage `json:"address,omitempty" db:"address"`
	Website   string `json:"website,omitempty" db:"website"`

	// Contact
	ContactName       string `json:"contact_name,omitempty" db:"contact_name"`
	ContactEmail      string `json:"contact_email,omitempty" db:"contact_email"`
	ContactPhone      string `json:"contact_phone,omitempty" db:"contact_phone"`
	ContactDepartment string `json:"contact_department,omitempty" db:"contact_department"`

	// GDPR role & service
	Role               VendorRole `json:"role" db:"role"`
	ServiceCategory    string     `json:"service_category,omitempty" db:"service_category"`
	ServiceDescription string     `json:"service_description,omitempty" db:"service_description"`
	DataAccessLevel    string     `json:"data_access_level,omitempty" db:"data_access_level"`

	// Processing details (JSONB)
	ProcessingLocations json.RawMessage `json:"processing_locations,omitempty" db:"processing_locations"`
	Certifications      json.RawMessage `json:"certifications,omitempty" db:"certifications"`

	// Risk scoring
	InherentRiskScore    *int `json:"inherent_risk_score,omitempty" db:"inherent_risk_score"`
	ResidualRiskScore    *int `json:"residual_risk_score,omitempty" db:"residual_risk_score"`
	ManualRiskAdjustment *int `json:"manual_risk_adjustment,omitempty" db:"manual_risk_adjustment"`

	// Review schedule
	ReviewFrequency string     `json:"review_frequency,omitempty" db:"review_frequency"`
	LastReviewDate  *time.Time `json:"last_review_date,omitempty" db:"last_review_date"`
	NextReviewDate  *time.Time `json:"next_review_date,omitempty" db:"next_review_date"`

	// Links to processing activities (JSONB)
	ProcessingActivityIDs json.RawMessage `json:"processing_activity_ids,omitempty" db:"processing_activity_ids"`

	// Status & template
	Status     VendorStatus `json:"status" db:"status"`
	TemplateID *string      `json:"template_id,omitempty" db:"template_id"`

	// Audit
	CreatedAt time.Time `json:"created_at" db:"created_at"`
	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
	CreatedBy string    `json:"created_by" db:"created_by"`
}

// Contract represents a contract/AVV document associated with a vendor
type Contract struct {
	ID       uuid.UUID `json:"id" db:"id"`
	TenantID uuid.UUID `json:"tenant_id" db:"tenant_id"`
	VendorID uuid.UUID `json:"vendor_id" db:"vendor_id"`

	// File metadata
	FileName     string `json:"file_name" db:"file_name"`
	OriginalName string `json:"original_name" db:"original_name"`
	MimeType     string `json:"mime_type" db:"mime_type"`
	FileSize     *int64 `json:"file_size,omitempty" db:"file_size"`
	StoragePath  string `json:"storage_path" db:"storage_path"`

	// Document classification
	DocumentType DocumentType `json:"document_type" db:"document_type"`

	// Contract details
	Parties            json.RawMessage `json:"parties,omitempty" db:"parties"`
	EffectiveDate      *time.Time      `json:"effective_date,omitempty" db:"effective_date"`
	ExpirationDate     *time.Time      `json:"expiration_date,omitempty" db:"expiration_date"`
	AutoRenewal        bool            `json:"auto_renewal" db:"auto_renewal"`
	RenewalNoticePeriod string         `json:"renewal_notice_period,omitempty" db:"renewal_notice_period"`

	// Review
	ReviewStatus     string     `json:"review_status" db:"review_status"`
	ReviewCompletedAt *time.Time `json:"review_completed_at,omitempty" db:"review_completed_at"`
	ComplianceScore  *int       `json:"compliance_score,omitempty" db:"compliance_score"`

	// Versioning
	Version           string  `json:"version" db:"version"`
	PreviousVersionID *string `json:"previous_version_id,omitempty" db:"previous_version_id"`

	// Extracted content
	ExtractedText string `json:"extracted_text,omitempty" db:"extracted_text"`
	PageCount     *int   `json:"page_count,omitempty" db:"page_count"`

	// Audit
	CreatedAt time.Time `json:"created_at" db:"created_at"`
	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
	CreatedBy string    `json:"created_by" db:"created_by"`
}

// Finding represents a compliance finding from a contract review
type Finding struct {
	ID         uuid.UUID `json:"id" db:"id"`
	TenantID   uuid.UUID `json:"tenant_id" db:"tenant_id"`
	ContractID *string   `json:"contract_id,omitempty" db:"contract_id"`
	VendorID   uuid.UUID `json:"vendor_id" db:"vendor_id"`

	// Finding details
	FindingType    FindingType `json:"finding_type" db:"finding_type"`
	Category       string      `json:"category" db:"category"`
	Severity       string      `json:"severity" db:"severity"`
	Title          string      `json:"title" db:"title"`
	Description    string      `json:"description" db:"description"`
	Recommendation string      `json:"recommendation,omitempty" db:"recommendation"`

	// Evidence (JSONB)
	Citations json.RawMessage `json:"citations,omitempty" db:"citations"`

	// Resolution workflow
	Status     FindingStatus `json:"status" db:"status"`
	Assignee   string        `json:"assignee,omitempty" db:"assignee"`
	DueDate    *time.Time    `json:"due_date,omitempty" db:"due_date"`
	Resolution string        `json:"resolution,omitempty" db:"resolution"`
	ResolvedAt *time.Time    `json:"resolved_at,omitempty" db:"resolved_at"`
	ResolvedBy *string       `json:"resolved_by,omitempty" db:"resolved_by"`

	// Audit
	CreatedAt time.Time `json:"created_at" db:"created_at"`
	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
}

// ControlInstance represents an applied control assessment for a specific vendor
type ControlInstance struct {
	ID       uuid.UUID `json:"id" db:"id"`
	TenantID uuid.UUID `json:"tenant_id" db:"tenant_id"`
	VendorID uuid.UUID `json:"vendor_id" db:"vendor_id"`

	// Control reference
	ControlID     string `json:"control_id" db:"control_id"`
	ControlDomain string `json:"control_domain" db:"control_domain"`

	// Assessment
	Status      ControlStatus   `json:"status" db:"status"`
	EvidenceIDs json.RawMessage `json:"evidence_ids,omitempty" db:"evidence_ids"`
	Notes       string          `json:"notes,omitempty" db:"notes"`

	// Assessment tracking
	LastAssessedAt   *time.Time `json:"last_assessed_at,omitempty" db:"last_assessed_at"`
	LastAssessedBy   *string    `json:"last_assessed_by,omitempty" db:"last_assessed_by"`
	NextAssessmentDate *time.Time `json:"next_assessment_date,omitempty" db:"next_assessment_date"`

	// Audit
	CreatedAt time.Time `json:"created_at" db:"created_at"`
	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
}

// Template represents a pre-filled vendor compliance template
type Template struct {
	ID       uuid.UUID `json:"id" db:"id"`
	TenantID *string   `json:"tenant_id,omitempty" db:"tenant_id"`

	// Template classification
	TemplateType string `json:"template_type" db:"template_type"`
	TemplateID   string `json:"template_id" db:"template_id"`
	Category     string `json:"category" db:"category"`

	// Localized names & descriptions
	NameDE        string `json:"name_de" db:"name_de"`
	NameEN        string `json:"name_en" db:"name_en"`
	DescriptionDE string `json:"description_de" db:"description_de"`
	DescriptionEN string `json:"description_en" db:"description_en"`

	// Template content (JSONB)
	TemplateData json.RawMessage `json:"template_data" db:"template_data"`

	// Classification
	Industry string          `json:"industry,omitempty" db:"industry"`
	Tags     json.RawMessage `json:"tags,omitempty" db:"tags"`

	// Flags
	IsSystem bool `json:"is_system" db:"is_system"`
	IsActive bool `json:"is_active" db:"is_active"`

	// Usage tracking
	UsageCount int `json:"usage_count" db:"usage_count"`

	// Audit
	CreatedAt time.Time `json:"created_at" db:"created_at"`
	UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
}

// ============================================================================
// Statistics
// ============================================================================

// VendorStats contains aggregated vendor compliance statistics for a tenant
type VendorStats struct {
	TotalVendors     int            `json:"total_vendors"`
	ByStatus         map[string]int `json:"by_status"`
	ByRole           map[string]int `json:"by_role"`
	ByRiskLevel      map[string]int `json:"by_risk_level"`
	PendingReviews   int            `json:"pending_reviews"`
	ExpiredContracts int            `json:"expired_contracts"`
}

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

// -- Vendor -------------------------------------------------------------------

// CreateVendorRequest is the API request for creating a vendor
type CreateVendorRequest struct {
	Name               string          `json:"name" binding:"required"`
	LegalForm          string          `json:"legal_form,omitempty"`
	Country            string          `json:"country" binding:"required"`
	Address            json.RawMessage `json:"address,omitempty"`
	Website            string          `json:"website,omitempty"`
	ContactName        string          `json:"contact_name,omitempty"`
	ContactEmail       string          `json:"contact_email,omitempty"`
	ContactPhone       string          `json:"contact_phone,omitempty"`
	ContactDepartment  string          `json:"contact_department,omitempty"`
	Role               VendorRole      `json:"role" binding:"required"`
	ServiceCategory    string          `json:"service_category,omitempty"`
	ServiceDescription string          `json:"service_description,omitempty"`
	DataAccessLevel    string          `json:"data_access_level,omitempty"`
	ProcessingLocations json.RawMessage `json:"processing_locations,omitempty"`
	Certifications     json.RawMessage `json:"certifications,omitempty"`
	ReviewFrequency    string          `json:"review_frequency,omitempty"`
	ProcessingActivityIDs json.RawMessage `json:"processing_activity_ids,omitempty"`
	TemplateID         *string         `json:"template_id,omitempty"`
}

// UpdateVendorRequest is the API request for updating a vendor
type UpdateVendorRequest struct {
	Name               *string         `json:"name,omitempty"`
	LegalForm          *string         `json:"legal_form,omitempty"`
	Country            *string         `json:"country,omitempty"`
	Address            json.RawMessage `json:"address,omitempty"`
	Website            *string         `json:"website,omitempty"`
	ContactName        *string         `json:"contact_name,omitempty"`
	ContactEmail       *string         `json:"contact_email,omitempty"`
	ContactPhone       *string         `json:"contact_phone,omitempty"`
	ContactDepartment  *string         `json:"contact_department,omitempty"`
	Role               *VendorRole     `json:"role,omitempty"`
	ServiceCategory    *string         `json:"service_category,omitempty"`
	ServiceDescription *string         `json:"service_description,omitempty"`
	DataAccessLevel    *string         `json:"data_access_level,omitempty"`
	ProcessingLocations json.RawMessage `json:"processing_locations,omitempty"`
	Certifications     json.RawMessage `json:"certifications,omitempty"`
	InherentRiskScore  *int            `json:"inherent_risk_score,omitempty"`
	ResidualRiskScore  *int            `json:"residual_risk_score,omitempty"`
	ManualRiskAdjustment *int          `json:"manual_risk_adjustment,omitempty"`
	ReviewFrequency    *string         `json:"review_frequency,omitempty"`
	LastReviewDate     *time.Time      `json:"last_review_date,omitempty"`
	NextReviewDate     *time.Time      `json:"next_review_date,omitempty"`
	ProcessingActivityIDs json.RawMessage `json:"processing_activity_ids,omitempty"`
	Status             *VendorStatus   `json:"status,omitempty"`
	TemplateID         *string         `json:"template_id,omitempty"`
}

// -- Contract -----------------------------------------------------------------

// CreateContractRequest is the API request for creating a contract
type CreateContractRequest struct {
	VendorID           uuid.UUID       `json:"vendor_id" binding:"required"`
	FileName           string          `json:"file_name" binding:"required"`
	OriginalName       string          `json:"original_name" binding:"required"`
	MimeType           string          `json:"mime_type" binding:"required"`
	FileSize           *int64          `json:"file_size,omitempty"`
	StoragePath        string          `json:"storage_path" binding:"required"`
	DocumentType       DocumentType    `json:"document_type" binding:"required"`
	Parties            json.RawMessage `json:"parties,omitempty"`
	EffectiveDate      *time.Time      `json:"effective_date,omitempty"`
	ExpirationDate     *time.Time      `json:"expiration_date,omitempty"`
	AutoRenewal        bool            `json:"auto_renewal"`
	RenewalNoticePeriod string         `json:"renewal_notice_period,omitempty"`
	Version            string          `json:"version,omitempty"`
	PreviousVersionID  *string         `json:"previous_version_id,omitempty"`
}

// UpdateContractRequest is the API request for updating a contract
type UpdateContractRequest struct {
	DocumentType       *DocumentType   `json:"document_type,omitempty"`
	Parties            json.RawMessage `json:"parties,omitempty"`
	EffectiveDate      *time.Time      `json:"effective_date,omitempty"`
	ExpirationDate     *time.Time      `json:"expiration_date,omitempty"`
	AutoRenewal        *bool           `json:"auto_renewal,omitempty"`
	RenewalNoticePeriod *string        `json:"renewal_notice_period,omitempty"`
	ReviewStatus       *string         `json:"review_status,omitempty"`
	ReviewCompletedAt  *time.Time      `json:"review_completed_at,omitempty"`
	ComplianceScore    *int            `json:"compliance_score,omitempty"`
	Version            *string         `json:"version,omitempty"`
	ExtractedText      *string         `json:"extracted_text,omitempty"`
	PageCount          *int            `json:"page_count,omitempty"`
}

// -- Finding ------------------------------------------------------------------

// CreateFindingRequest is the API request for creating a compliance finding
type CreateFindingRequest struct {
	ContractID     *string         `json:"contract_id,omitempty"`
	VendorID       uuid.UUID       `json:"vendor_id" binding:"required"`
	FindingType    FindingType     `json:"finding_type" binding:"required"`
	Category       string          `json:"category" binding:"required"`
	Severity       string          `json:"severity" binding:"required"`
	Title          string          `json:"title" binding:"required"`
	Description    string          `json:"description" binding:"required"`
	Recommendation string          `json:"recommendation,omitempty"`
	Citations      json.RawMessage `json:"citations,omitempty"`
	Assignee       string          `json:"assignee,omitempty"`
	DueDate        *time.Time      `json:"due_date,omitempty"`
}

// UpdateFindingRequest is the API request for updating a finding
type UpdateFindingRequest struct {
	FindingType    *FindingType    `json:"finding_type,omitempty"`
	Category       *string         `json:"category,omitempty"`
	Severity       *string         `json:"severity,omitempty"`
	Title          *string         `json:"title,omitempty"`
	Description    *string         `json:"description,omitempty"`
	Recommendation *string         `json:"recommendation,omitempty"`
	Citations      json.RawMessage `json:"citations,omitempty"`
	Status         *FindingStatus  `json:"status,omitempty"`
	Assignee       *string         `json:"assignee,omitempty"`
	DueDate        *time.Time      `json:"due_date,omitempty"`
	Resolution     *string         `json:"resolution,omitempty"`
}

// ResolveFindingRequest is the API request for resolving a finding
type ResolveFindingRequest struct {
	Resolution string `json:"resolution" binding:"required"`
}

// -- ControlInstance ----------------------------------------------------------

// UpdateControlInstanceRequest is the API request for updating a control instance
type UpdateControlInstanceRequest struct {
	Status             *ControlStatus  `json:"status,omitempty"`
	EvidenceIDs        json.RawMessage `json:"evidence_ids,omitempty"`
	Notes              *string         `json:"notes,omitempty"`
	NextAssessmentDate *time.Time      `json:"next_assessment_date,omitempty"`
}

// -- Template -----------------------------------------------------------------

// CreateTemplateRequest is the API request for creating a vendor template
type CreateTemplateRequest struct {
	TemplateType  string          `json:"template_type" binding:"required"`
	TemplateID    string          `json:"template_id" binding:"required"`
	Category      string          `json:"category" binding:"required"`
	NameDE        string          `json:"name_de" binding:"required"`
	NameEN        string          `json:"name_en" binding:"required"`
	DescriptionDE string          `json:"description_de,omitempty"`
	DescriptionEN string          `json:"description_en,omitempty"`
	TemplateData  json.RawMessage `json:"template_data" binding:"required"`
	Industry      string          `json:"industry,omitempty"`
	Tags          json.RawMessage `json:"tags,omitempty"`
	IsSystem      bool            `json:"is_system"`
}

// ============================================================================
// List / Filter Types
// ============================================================================

// VendorFilters defines filters for listing vendors
type VendorFilters struct {
	Status VendorStatus
	Role   VendorRole
	Search string
	Limit  int
	Offset int
}

// ContractFilters defines filters for listing contracts
type ContractFilters struct {
	VendorID     *uuid.UUID
	DocumentType DocumentType
	ReviewStatus string
	Limit        int
	Offset       int
}

// FindingFilters defines filters for listing findings
type FindingFilters struct {
	VendorID   *uuid.UUID
	ContractID *string
	Status     FindingStatus
	FindingType FindingType
	Severity   string
	Limit      int
	Offset     int
}

// VendorListResponse is the API response for listing vendors
type VendorListResponse struct {
	Vendors []Vendor `json:"vendors"`
	Total   int      `json:"total"`
}

// ContractListResponse is the API response for listing contracts
type ContractListResponse struct {
	Contracts []Contract `json:"contracts"`
	Total     int        `json:"total"`
}

// FindingListResponse is the API response for listing findings
type FindingListResponse struct {
	Findings []Finding `json:"findings"`
	Total    int       `json:"total"`
}