package portfolio

import (
	"time"

	"github.com/google/uuid"
)

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

// PortfolioStatus represents the status of a portfolio
type PortfolioStatus string

const (
	PortfolioStatusDraft     PortfolioStatus = "DRAFT"
	PortfolioStatusActive    PortfolioStatus = "ACTIVE"
	PortfolioStatusReview    PortfolioStatus = "REVIEW"
	PortfolioStatusApproved  PortfolioStatus = "APPROVED"
	PortfolioStatusArchived  PortfolioStatus = "ARCHIVED"
)

// ItemType represents the type of item in a portfolio
type ItemType string

const (
	ItemTypeAssessment ItemType = "ASSESSMENT"
	ItemTypeRoadmap    ItemType = "ROADMAP"
	ItemTypeWorkshop   ItemType = "WORKSHOP"
	ItemTypeDocument   ItemType = "DOCUMENT"
)

// MergeStrategy defines how to merge portfolios
type MergeStrategy string

const (
	MergeStrategyUnion     MergeStrategy = "UNION"      // Combine all items (default)
	MergeStrategyIntersect MergeStrategy = "INTERSECT"  // Only overlapping items
	MergeStrategyReplace   MergeStrategy = "REPLACE"    // Replace target with source
)

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

// Portfolio represents a collection of AI use case assessments and related artifacts
type Portfolio struct {
	ID          uuid.UUID       `json:"id"`
	TenantID    uuid.UUID       `json:"tenant_id"`
	NamespaceID *uuid.UUID      `json:"namespace_id,omitempty"`

	// Info
	Name        string          `json:"name"`
	Description string          `json:"description,omitempty"`
	Status      PortfolioStatus `json:"status"`

	// Organization
	Department  string          `json:"department,omitempty"`
	BusinessUnit string         `json:"business_unit,omitempty"`
	Owner       string          `json:"owner,omitempty"`
	OwnerEmail  string          `json:"owner_email,omitempty"`

	// Aggregated metrics (computed)
	TotalAssessments    int     `json:"total_assessments"`
	TotalRoadmaps       int     `json:"total_roadmaps"`
	TotalWorkshops      int     `json:"total_workshops"`
	AvgRiskScore        float64 `json:"avg_risk_score"`
	HighRiskCount       int     `json:"high_risk_count"`
	ConditionalCount    int     `json:"conditional_count"`
	ApprovedCount       int     `json:"approved_count"`
	ComplianceScore     float64 `json:"compliance_score"` // 0-100

	// Settings
	Settings PortfolioSettings `json:"settings"`

	// Audit
	CreatedAt   time.Time  `json:"created_at"`
	UpdatedAt   time.Time  `json:"updated_at"`
	CreatedBy   uuid.UUID  `json:"created_by"`
	ApprovedAt  *time.Time `json:"approved_at,omitempty"`
	ApprovedBy  *uuid.UUID `json:"approved_by,omitempty"`
}

// PortfolioSettings contains configuration options
type PortfolioSettings struct {
	AutoUpdateMetrics  bool `json:"auto_update_metrics"`  // Recalculate on changes
	RequireApproval    bool `json:"require_approval"`     // Require approval before active
	NotifyOnHighRisk   bool `json:"notify_on_high_risk"`  // Alert on high risk items
	AllowExternalShare bool `json:"allow_external_share"` // Share with external users
}

// PortfolioItem represents an item linked to a portfolio
type PortfolioItem struct {
	ID          uuid.UUID  `json:"id"`
	PortfolioID uuid.UUID  `json:"portfolio_id"`
	ItemType    ItemType   `json:"item_type"`
	ItemID      uuid.UUID  `json:"item_id"`      // Reference to the actual item

	// Cached info from the linked item
	Title       string     `json:"title"`
	Status      string     `json:"status,omitempty"`
	RiskLevel   string     `json:"risk_level,omitempty"`
	RiskScore   int        `json:"risk_score,omitempty"`
	Feasibility string     `json:"feasibility,omitempty"`

	// Ordering and categorization
	SortOrder   int        `json:"sort_order"`
	Tags        []string   `json:"tags,omitempty"`
	Notes       string     `json:"notes,omitempty"`

	// Audit
	AddedAt     time.Time  `json:"added_at"`
	AddedBy     uuid.UUID  `json:"added_by"`
}

// ============================================================================
// Merge Operations
// ============================================================================

// MergeRequest represents a request to merge portfolios
type MergeRequest struct {
	SourcePortfolioID uuid.UUID     `json:"source_portfolio_id"`
	TargetPortfolioID uuid.UUID     `json:"target_portfolio_id"`
	Strategy          MergeStrategy `json:"strategy"`
	DeleteSource      bool          `json:"delete_source"`       // Delete source after merge
	IncludeRoadmaps   bool          `json:"include_roadmaps"`
	IncludeWorkshops  bool          `json:"include_workshops"`
}

// MergeResult represents the result of a merge operation
type MergeResult struct {
	TargetPortfolio   *Portfolio      `json:"target_portfolio"`
	ItemsAdded        int             `json:"items_added"`
	ItemsSkipped      int             `json:"items_skipped"`      // Duplicates or excluded
	ItemsUpdated      int             `json:"items_updated"`
	SourceDeleted     bool            `json:"source_deleted"`
	ConflictsResolved []MergeConflict `json:"conflicts_resolved,omitempty"`
}

// MergeConflict describes a conflict during merge
type MergeConflict struct {
	ItemID      uuid.UUID `json:"item_id"`
	ItemType    ItemType  `json:"item_type"`
	Reason      string    `json:"reason"`
	Resolution  string    `json:"resolution"` // "kept_source", "kept_target", "merged"
}

// ============================================================================
// Aggregated Views
// ============================================================================

// PortfolioSummary contains aggregated portfolio information
type PortfolioSummary struct {
	Portfolio       *Portfolio         `json:"portfolio"`
	Items           []PortfolioItem    `json:"items"`
	RiskDistribution RiskDistribution  `json:"risk_distribution"`
	FeasibilityDist  FeasibilityDist   `json:"feasibility_distribution"`
	RecentActivity   []ActivityEntry   `json:"recent_activity,omitempty"`
}

// RiskDistribution shows the distribution of risk levels
type RiskDistribution struct {
	Minimal      int `json:"minimal"`
	Low          int `json:"low"`
	Medium       int `json:"medium"`
	High         int `json:"high"`
	Unacceptable int `json:"unacceptable"`
}

// FeasibilityDist shows the distribution of feasibility verdicts
type FeasibilityDist struct {
	Yes         int `json:"yes"`
	Conditional int `json:"conditional"`
	No          int `json:"no"`
}

// ActivityEntry represents recent activity on a portfolio
type ActivityEntry struct {
	Timestamp   time.Time `json:"timestamp"`
	Action      string    `json:"action"`      // "added", "removed", "updated", "merged"
	ItemType    ItemType  `json:"item_type"`
	ItemID      uuid.UUID `json:"item_id"`
	ItemTitle   string    `json:"item_title"`
	UserID      uuid.UUID `json:"user_id"`
}

// PortfolioStats contains statistical information
type PortfolioStats struct {
	TotalItems          int                `json:"total_items"`
	ItemsByType         map[ItemType]int   `json:"items_by_type"`
	RiskDistribution    RiskDistribution   `json:"risk_distribution"`
	FeasibilityDist     FeasibilityDist    `json:"feasibility_distribution"`
	AvgRiskScore        float64            `json:"avg_risk_score"`
	ComplianceScore     float64            `json:"compliance_score"`
	DSFARequired        int                `json:"dsfa_required"`
	ControlsRequired    int                `json:"controls_required"`
	LastUpdated         time.Time          `json:"last_updated"`
}

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

// CreatePortfolioRequest is the API request for creating a portfolio
type CreatePortfolioRequest struct {
	Name         string            `json:"name"`
	Description  string            `json:"description,omitempty"`
	Department   string            `json:"department,omitempty"`
	BusinessUnit string            `json:"business_unit,omitempty"`
	Owner        string            `json:"owner,omitempty"`
	OwnerEmail   string            `json:"owner_email,omitempty"`
	Settings     PortfolioSettings `json:"settings,omitempty"`
}

// UpdatePortfolioRequest is the API request for updating a portfolio
type UpdatePortfolioRequest struct {
	Name         string            `json:"name,omitempty"`
	Description  string            `json:"description,omitempty"`
	Status       PortfolioStatus   `json:"status,omitempty"`
	Department   string            `json:"department,omitempty"`
	BusinessUnit string            `json:"business_unit,omitempty"`
	Owner        string            `json:"owner,omitempty"`
	OwnerEmail   string            `json:"owner_email,omitempty"`
	Settings     *PortfolioSettings `json:"settings,omitempty"`
}

// AddItemRequest is the API request for adding an item to a portfolio
type AddItemRequest struct {
	ItemType ItemType  `json:"item_type"`
	ItemID   uuid.UUID `json:"item_id"`
	Tags     []string  `json:"tags,omitempty"`
	Notes    string    `json:"notes,omitempty"`
}

// BulkAddItemsRequest is the API request for adding multiple items
type BulkAddItemsRequest struct {
	Items []AddItemRequest `json:"items"`
}

// BulkAddItemsResponse is the API response for bulk adding items
type BulkAddItemsResponse struct {
	Added   int      `json:"added"`
	Skipped int      `json:"skipped"`
	Errors  []string `json:"errors,omitempty"`
}

// PortfolioFilters defines filters for listing portfolios
type PortfolioFilters struct {
	Status       PortfolioStatus
	Department   string
	BusinessUnit string
	Owner        string
	MinRiskScore *float64
	MaxRiskScore *float64
	Limit        int
	Offset       int
}

// ComparePortfoliosRequest is the API request for comparing portfolios
type ComparePortfoliosRequest struct {
	PortfolioIDs []uuid.UUID `json:"portfolio_ids"` // 2-5 portfolios to compare
}

// ComparePortfoliosResponse is the API response for portfolio comparison
type ComparePortfoliosResponse struct {
	Portfolios      []Portfolio        `json:"portfolios"`
	Comparison      PortfolioComparison `json:"comparison"`
}

// PortfolioComparison contains comparative metrics
type PortfolioComparison struct {
	RiskScores       map[string]float64        `json:"risk_scores"`        // portfolio_id -> score
	ComplianceScores map[string]float64        `json:"compliance_scores"`
	ItemCounts       map[string]int            `json:"item_counts"`
	CommonItems      []uuid.UUID               `json:"common_items"`       // Items in multiple portfolios
	UniqueItems      map[string][]uuid.UUID    `json:"unique_items"`       // portfolio_id -> item_ids
}