package domain

import (
	"context"
	"fmt"
	"time"

	"github.com/lib/pq"
	"gorm.io/datatypes"
)

// ProductCategory defines the category of a product
type ProductCategory string

const (
	ProductCategoryChemicals     ProductCategory = "chemicals"
	ProductCategoryEquipment     ProductCategory = "equipment"
	ProductCategoryMaterials     ProductCategory = "materials"
	ProductCategoryFood          ProductCategory = "food"
	ProductCategoryPackaging     ProductCategory = "packaging"
	ProductCategoryOilGas        ProductCategory = "oil_gas"
	ProductCategoryConstruction  ProductCategory = "construction"
	ProductCategoryManufacturing ProductCategory = "manufacturing"
	ProductCategoryOther         ProductCategory = "other"
)

// Product represents a product offered by an organization (database entity)
// Note: There's also a ProductJSON struct in organization.go for API serialization
type Product struct {
	ID             string          `gorm:"primaryKey;type:text"`
	Name           string          `gorm:"not null;type:text;index"`
	Category       ProductCategory `gorm:"not null;type:varchar(50);index"`
	Description    string          `gorm:"type:text"`
	UnitPrice      float64         `gorm:"type:decimal(10,2);index"` // € per unit
	MOQ            int             `gorm:"type:integer"`             // Minimum Order Quantity
	Certifications datatypes.JSON  `gorm:"default:'[]'"`             // []string

	// Business information
	OrganizationID string        `gorm:"not null;type:text;index"`
	Organization   *Organization `gorm:"foreignKey:OrganizationID"`

	// Site information (for location-based matching)
	SiteID *string `gorm:"type:text;index"`
	Site   *Site   `gorm:"foreignKey:SiteID"`

	// Location (PostGIS Point for spatial queries)
	Location Point `gorm:"type:geometry(Point,4326)"` // PostGIS geometry point

	// Discovery and search fields
	SearchKeywords     string         `gorm:"type:text"`                                  // Full-text search keywords
	Tags               pq.StringArray `gorm:"type:text[]"`                                // Searchable tags array
	AvailabilityStatus string         `gorm:"type:varchar(20);default:'available';index"` // available, limited, out_of_stock
	Images             pq.StringArray `gorm:"type:text[]"`                                // Array of image URLs

	// Additional metadata
	Capacity       string         `gorm:"type:text"`               // Production capacity info
	Specifications datatypes.JSON `gorm:"type:jsonb;default:'{}'"` // Technical specifications
	Availability   string         `gorm:"type:text"`               // Availability status (legacy field, kept for compatibility)
	Sources        datatypes.JSON `gorm:"type:jsonb"`              // Data sources

	// Timestamps
	CreatedAt time.Time `gorm:"autoCreateTime"`
	UpdatedAt time.Time `gorm:"autoUpdateTime"`
}

// TableName specifies the table name for GORM
func (Product) TableName() string {
	return "products"
}

// ProductRepository defines operations for product management
type ProductRepository interface {
	Create(ctx context.Context, product *Product) error
	GetByID(ctx context.Context, id string) (*Product, error)
	GetByOrganization(ctx context.Context, organizationID string) ([]*Product, error)
	GetByCategory(ctx context.Context, category ProductCategory) ([]*Product, error)
	SearchByName(ctx context.Context, name string) ([]*Product, error)
	GetByPriceRange(ctx context.Context, minPrice, maxPrice float64) ([]*Product, error)
	Update(ctx context.Context, product *Product) error
	Delete(ctx context.Context, id string) error
	GetAll(ctx context.Context) ([]*Product, error)
	// Discovery methods
	SearchWithLocation(ctx context.Context, query string, location *Point, radiusKm float64) ([]*Product, error)
	GetBySite(ctx context.Context, siteID string) ([]*Product, error)
	GetNearby(ctx context.Context, lat, lng, radiusKm float64) ([]*Product, error)
}

// Validate performs business rule validation
func (p *Product) Validate() error {
	if p.Name == "" {
		return fmt.Errorf("product name cannot be empty")
	}
	if p.UnitPrice < 0 {
		return fmt.Errorf("unit price cannot be negative")
	}
	if p.MOQ < 0 {
		return fmt.Errorf("minimum order quantity cannot be negative")
	}
	return nil
}