// Procurement & Trading Domain
// Contains Procurement, Contract, Harvest, and related trading models

// Procurement-specific Enums
enum ProcurementStatus {
    PENDING
    QUALITY_ASSESSMENT
    APPROVED
    REJECTED
    IN_TRANSIT
    DELIVERED
    INVOICED
    PAID
    COMPLETED
    CANCELLED
    PARTIALLY_REJECTED
}

enum AgreementType {
    PURCHASE_AGREEMENT
    SUPPLY_CONTRACT
    EXCLUSIVE_SUPPLY
    SEASONAL_CONTRACT
    FORWARD_CONTRACT
    SPOT_CONTRACT
    CONSIGNMENT
    PARTNERSHIP
}

enum ContractStatus {
    DRAFT
    PENDING_REVIEW
    PENDING_SIGNATURE
    ACTIVE
    FULFILLED
    EXPIRED
    TERMINATED
    CANCELLED
    BREACH
    RENEWED
}

enum ProcurementAttachmentType {
    PRODUCT_PHOTO
    QUALITY_ASSESSMENT_PHOTO
    WEIGHING_PHOTO
    PACKAGING_PHOTO
    LOADING_PHOTO
    DELIVERY_PHOTO
    CONTRACT_DOCUMENT
    INVOICE
    RECEIPT
    PAYMENT_PROOF
    QUALITY_CERTIFICATE
    TRANSPORT_DOCUMENT
    REJECTION_PHOTO
    SIGNATURE_DOCUMENT
    OTHER_DOCUMENT
}

// Procurement Models
model Harvest {
    id           String         @id @default(cuid())
    farmerId     String
    farmId       String
    plotId       String?
    variantId    String
    quantity     Decimal // in kg
    harvestDate  DateTime
    qualityGrade QualityGrade
    waterContent Decimal? // percentage
    density      Decimal? // kg/m3
    notes        String?
    createdAt    DateTime       @default(now())
    updatedAt    DateTime       @updatedAt

    // Relations
    farmer      Farmer           @relation(fields: [farmerId], references: [id])
    farm        Farm             @relation(fields: [farmId], references: [id])
    plot        Plot?            @relation(fields: [plotId], references: [id])
    variant     ProductVariant   @relation(fields: [variantId], references: [id])
    procurement Procurement?
    modifiers   HarvestModifier[]

    @@index([farmerId, farmId])
    @@index([harvestDate])
    @@index([variantId])
    @@index([qualityGrade])
    @@index([plotId])
    @@map("harvests")
}

model Procurement {
    id              String            @id @default(cuid())
    procurementCode String            @unique
    farmerId        String
    buyerId         String?
    harvestId       String            @unique
    variantId       String
    
    // Quantity and quality details
    quantity        Decimal // in kg
    qualityGrade    QualityGrade
    waterContent    Decimal? // percentage
    density         Decimal? // kg/m3
    
    // Pricing details
    basePrice       Decimal // price per kg
    premiumRate     Decimal             @default(0) // percentage
    totalPrice      Decimal
    transportCost   Decimal?            @default(0)
    processingCost  Decimal?            @default(0)
    finalAmount     Decimal // total amount to be paid
    
    // Location and logistics
    pickupLocation  String?
    deliveryLocation String?
    pickupDate      DateTime?
    deliveryDate    DateTime?
    transportMethod String? // truck, motorcycle, etc.
    
    // Quality assessment
    assessedBy      String? // quality assessor ID
    assessmentDate  DateTime?
    assessmentNotes String?
    rejectedQuantity Decimal?           @default(0)
    rejectionReason String?
    
    // Payment details
    paymentMethod   PaymentMethod?
    paymentReference String?
    bankAccount     String?
    
    // Status and tracking
    status          ProcurementStatus @default(PENDING)
    procurementDate DateTime          @default(now())
    approvedDate    DateTime?
    approvedBy      String? // admin ID who approved
    paymentDate     DateTime?
    completedDate   DateTime?
    
    // Documentation
    contractId      String?           // link to formal contract
    contractNumber  String?
    invoiceNumber   String?
    receiptNumber   String?
    
    notes           String?
    createdAt       DateTime          @default(now())
    updatedAt       DateTime          @updatedAt

    // Relations
    farmer      Farmer                @relation(fields: [farmerId], references: [id])
    buyer       Buyer?                @relation(fields: [buyerId], references: [id])
    harvest     Harvest               @relation(fields: [harvestId], references: [id])
    variant     ProductVariant        @relation(fields: [variantId], references: [id])
    contract    Contract?             @relation(fields: [contractId], references: [id])
    attachments ProcurementAttachment[]

    @@index([procurementCode])
    @@index([farmerId, buyerId])
    @@index([status])
    @@index([procurementDate])
    @@index([variantId])
    @@index([qualityGrade])
    @@index([paymentMethod])
    @@map("procurements")
}

model Contract {
    id                String        @id @default(cuid())
    contractNumber    String        @unique
    farmerId          String
    buyerId           String
    productId         String?
    variantId         String?
    
    // Contract terms
    title             String
    description       String?
    contractType      AgreementType  @default(PURCHASE_AGREEMENT)
    
    // Pricing and quantity
    agreedPrice       Decimal       // price per unit
    minimumQuantity   Decimal?
    maximumQuantity   Decimal?
    totalValue        Decimal?
    unit              String        @default("kg")
    
    // Quality specifications
    qualityGrade      QualityGrade?
    qualityRequirements String?
    
    // Timeline
    startDate         DateTime
    endDate           DateTime
    deliverySchedule  String?       // delivery frequency/schedule
    
    // Payment terms
    paymentTerms      String?       // payment conditions
    paymentMethod     PaymentMethod?
    advancePayment    Decimal?      @default(0)
    advancePercentage Decimal?      @default(0)
    
    // Legal and compliance
    terms             String?       // full terms and conditions
    penalties         String?       // penalty clauses
    forcemajeure      String?       // force majeure clause
    governingLaw      String?       // applicable law
    
    // Status and tracking
    status            ContractStatus @default(DRAFT)
    signedDate        DateTime?
    signedByFarmer    Boolean       @default(false)
    signedByBuyer     Boolean       @default(false)
    farmerSignature   String?       // signature data or URL
    buyerSignature    String?       // signature data or URL
    witnessName       String?
    witnessSignature  String?
    
    // Performance tracking
    totalDelivered    Decimal?      @default(0)
    totalPaid         Decimal?      @default(0)
    deliveryCount     Int           @default(0)
    
    // Renewal and amendments
    renewalDate       DateTime?
    amendmentCount    Int           @default(0)
    parentContractId  String?       // for contract renewals
    
    // Documentation
    documentUrl       String?       // contract document
    attachmentUrls    String[]      // supporting documents
    
    notes             String?
    createdAt         DateTime      @default(now())
    updatedAt         DateTime      @updatedAt

    // Relations
    farmer            Farmer        @relation(fields: [farmerId], references: [id])
    buyer             Buyer         @relation(fields: [buyerId], references: [id])
    product           Product?      @relation(fields: [productId], references: [id])
    variant           ProductVariant? @relation(fields: [variantId], references: [id])
    parentContract    Contract?     @relation("ContractRenewal", fields: [parentContractId], references: [id])
    renewalContracts  Contract[]    @relation("ContractRenewal")
    procurements      Procurement[] // deliveries under this contract

    @@index([contractNumber])
    @@index([farmerId, buyerId])
    @@index([status])
    @@index([startDate, endDate])
    @@index([productId, variantId])
    @@index([signedDate])
    @@map("contracts")
}

model ProcurementAttachment {
    id            String                    @id @default(cuid())
    procurementId String
    type          ProcurementAttachmentType
    title         String
    description   String?
    fileUrl       String
    fileName      String
    fileSize      Int? // in bytes
    mimeType      String?
    uploadedBy    String? // user ID who uploaded
    takenDate     DateTime? // when photo was taken
    gpsLocation   Json? // GeoJSON point where photo was taken
    isVerified    Boolean                   @default(false)
    verifiedBy    String? // admin ID who verified
    verifiedAt    DateTime?
    createdAt     DateTime                  @default(now())
    updatedAt     DateTime                  @updatedAt

    // Relations
    procurement Procurement @relation(fields: [procurementId], references: [id], onDelete: Cascade)

    @@index([procurementId])
    @@index([type])
    @@index([isVerified])
    @@index([createdAt])
    @@map("procurement_attachments")
}