//! BrazilianPaymentEntity derive macro implementation
//!
//! Enhanced Brazilian market features for payments including PIX integration,
//! tax calculations (ICMS, PIS/COFINS), Brazilian document validation,
//! and currency formatting.

use proc_macro::TokenStream;
use proc_macro2::TokenStream as TokenStream2;
use quote::{quote, format_ident};
use syn::{parse_macro_input, DeriveInput, Data, Fields, Field, Attribute, Meta, NestedMeta, Lit};

/// Brazilian payment configuration
#[derive(Default)]
struct BrazilianConfig {
    pix_support: bool,
    boleto_support: bool,
    tax_calculation: bool,
    tax_type: Option<String>,
    currency: String,
    tax_rate_icms: f64,
    tax_rate_pis: f64,
    tax_rate_cofins: f64,
}

impl BrazilianConfig {
    fn from_attrs(attrs: &[Attribute]) -> Self {
        let mut config = BrazilianConfig {
            pix_support: true,
            boleto_support: true,
            tax_calculation: true,
            currency: "BRL".to_string(),
            tax_rate_icms: 0.18,    // 18% ICMS default
            tax_rate_pis: 0.0165,   // 1.65% PIS
            tax_rate_cofins: 0.076, // 7.6% COFINS
            ..Default::default()
        };
        
        for attr in attrs {
            if attr.path.is_ident("brazilian_payment") {
                if let Ok(Meta::List(meta_list)) = attr.parse_meta() {
                    for nested_meta in meta_list.nested {
                        match nested_meta {
                            NestedMeta::Meta(Meta::NameValue(name_value)) => {
                                match name_value.path.get_ident().map(|i| i.to_string()).as_deref() {
                                    Some("tax_type") => {
                                        if let Lit::Str(lit_str) = name_value.lit {
                                            config.tax_type = Some(lit_str.value());
                                        }
                                    }
                                    Some("currency") => {
                                        if let Lit::Str(lit_str) = name_value.lit {
                                            config.currency = lit_str.value();
                                        }
                                    }
                                    Some("icms_rate") => {
                                        if let Lit::Float(lit_float) = name_value.lit {
                                            config.tax_rate_icms = lit_float.base10_parse().unwrap_or(0.18);
                                        }
                                    }
                                    Some("pis_rate") => {
                                        if let Lit::Float(lit_float) = name_value.lit {
                                            config.tax_rate_pis = lit_float.base10_parse().unwrap_or(0.0165);
                                        }
                                    }
                                    Some("cofins_rate") => {
                                        if let Lit::Float(lit_float) = name_value.lit {
                                            config.tax_rate_cofins = lit_float.base10_parse().unwrap_or(0.076);
                                        }
                                    }
                                    _ => {}
                                }
                            }
                            NestedMeta::Meta(Meta::Path(path)) => {
                                if path.is_ident("no_pix") {
                                    config.pix_support = false;
                                } else if path.is_ident("no_boleto") {
                                    config.boleto_support = false;
                                } else if path.is_ident("no_tax") {
                                    config.tax_calculation = false;
                                }
                            }
                            _ => {}
                        }
                    }
                }
            }
        }
        
        config
    }
}

pub fn derive_brazilian_payment_entity(input: TokenStream) -> TokenStream {
    let input = parse_macro_input!(input as DeriveInput);
    let struct_name = &input.ident;
    let config = BrazilianConfig::from_attrs(&input.attrs);
    
    let pix_methods = if config.pix_support {
        quote! {
            /// Generate PIX QR Code for payment
            pub fn generate_pix_qr_code(&self) -> Result<String, BrazilianPaymentError> {
                if let Some(amount) = self.get_amount() {
                    let pix_data = PixData {
                        merchant_name: "Pleme Payment",
                        merchant_city: "São Paulo",
                        transaction_id: self.get_id().to_string(),
                        amount: amount,
                        currency: &#config.currency,
                    };
                    
                    let qr_code = generate_pix_qr(&pix_data)?;
                    
                    tracing::info!(
                        entity = %stringify!(#struct_name),
                        transaction_id = %self.get_id(),
                        amount = %amount,
                        "PIX QR Code generated"
                    );
                    
                    Ok(qr_code)
                } else {
                    Err(BrazilianPaymentError::InvalidAmount("Amount is required for PIX".to_string()))
                }
            }
            
            /// Validate PIX key format and type
            pub fn validate_pix_key(key: &str, key_type: PixKeyType) -> Result<(), BrazilianPaymentError> {
                match key_type {
                    PixKeyType::Cpf => {
                        if !Self::validate_cpf(key) {
                            return Err(BrazilianPaymentError::InvalidPixKey(
                                format!("Invalid CPF: {}", key)
                            ));
                        }
                    }
                    PixKeyType::Cnpj => {
                        if !Self::validate_cnpj(key) {
                            return Err(BrazilianPaymentError::InvalidPixKey(
                                format!("Invalid CNPJ: {}", key)
                            ));
                        }
                    }
                    PixKeyType::Email => {
                        if !Self::validate_email(key) {
                            return Err(BrazilianPaymentError::InvalidPixKey(
                                format!("Invalid email: {}", key)
                            ));
                        }
                    }
                    PixKeyType::Phone => {
                        if !Self::validate_brazilian_phone(key) {
                            return Err(BrazilianPaymentError::InvalidPixKey(
                                format!("Invalid Brazilian phone: {}", key)
                            ));
                        }
                    }
                    PixKeyType::Random => {
                        if !Self::validate_uuid_key(key) {
                            return Err(BrazilianPaymentError::InvalidPixKey(
                                format!("Invalid random PIX key: {}", key)
                            ));
                        }
                    }
                }
                
                tracing::debug!(
                    entity = %stringify!(#struct_name),
                    key_type = ?key_type,
                    "PIX key validation passed"
                );
                
                Ok(())
            }
            
            /// Validate UUID format for random PIX keys
            fn validate_uuid_key(key: &str) -> bool {
                uuid::Uuid::parse_str(key).is_ok()
            }
            
            /// Process PIX instant payment confirmation
            pub fn process_pix_confirmation(&mut self, end_to_end_id: &str, psp_reference: &str) -> Result<(), BrazilianPaymentError> {
                if end_to_end_id.len() != 32 {
                    return Err(BrazilianPaymentError::InvalidPixData(
                        "Invalid end-to-end ID format".to_string()
                    ));
                }
                
                self.set_status(PaymentStatus::Completed);
                self.set_updated_at(chrono::Utc::now());
                
                tracing::info!(
                    entity = %stringify!(#struct_name),
                    transaction_id = %self.get_id(),
                    end_to_end_id = %end_to_end_id,
                    psp_reference = %psp_reference,
                    "PIX payment confirmed"
                );
                
                Ok(())
            }
        }
    } else {
        quote! {}
    };
    
    let boleto_methods = if config.boleto_support {
        quote! {
            /// Generate Boleto bancário for payment
            pub fn generate_boleto(&self) -> Result<BoletoData, BrazilianPaymentError> {
                if let Some(amount) = self.get_amount() {
                    let due_date = chrono::Utc::now() + chrono::Duration::days(3);
                    
                    let boleto = BoletoData {
                        bank_code: "341", // Itaú default
                        agency: "1234",
                        account: "12345-6",
                        wallet: "109",
                        our_number: format!("{:013}", self.get_id().as_u128() % 10_000_000_000_000),
                        document_number: self.get_id().to_string(),
                        due_date,
                        amount,
                        payer_name: "Cliente".to_string(), // Would be extracted from customer data
                        payer_document: "000.000.000-00".to_string(),
                        instructions: vec![
                            "Não receber após o vencimento".to_string(),
                            "Pagamento via PIX disponível".to_string(),
                        ],
                    };
                    
                    tracing::info!(
                        entity = %stringify!(#struct_name),
                        transaction_id = %self.get_id(),
                        due_date = %due_date,
                        amount = %amount,
                        "Boleto generated"
                    );
                    
                    Ok(boleto)
                } else {
                    Err(BrazilianPaymentError::InvalidAmount("Amount is required for Boleto".to_string()))
                }
            }
            
            /// Calculate Boleto verification digit
            pub fn calculate_boleto_dv(code: &str) -> String {
                // Implement modulo 11 verification digit calculation
                let weights = [2, 3, 4, 5, 6, 7, 8, 9];
                let mut sum = 0;
                
                for (i, digit) in code.chars().rev().enumerate() {
                    if let Some(d) = digit.to_digit(10) {
                        sum += (d as usize) * weights[i % weights.len()];
                    }
                }
                
                let remainder = sum % 11;
                let dv = match remainder {
                    0 | 1 => 0,
                    _ => 11 - remainder,
                };
                
                dv.to_string()
            }
        }
    } else {
        quote! {}
    };
    
    let tax_methods = if config.tax_calculation {
        let icms_rate = config.tax_rate_icms;
        let pis_rate = config.tax_rate_pis;
        let cofins_rate = config.tax_rate_cofins;
        
        quote! {
            /// Calculate Brazilian taxes (ICMS, PIS, COFINS)
            pub fn calculate_brazilian_taxes(&self) -> Result<BrazilianTaxBreakdown, BrazilianPaymentError> {
                if let Some(gross_amount) = self.get_amount() {
                    let icms = gross_amount * rust_decimal::Decimal::from_f64(#icms_rate)
                        .ok_or(BrazilianPaymentError::TaxCalculationError("Invalid ICMS rate".to_string()))?;
                    
                    let pis = gross_amount * rust_decimal::Decimal::from_f64(#pis_rate)
                        .ok_or(BrazilianPaymentError::TaxCalculationError("Invalid PIS rate".to_string()))?;
                    
                    let cofins = gross_amount * rust_decimal::Decimal::from_f64(#cofins_rate)
                        .ok_or(BrazilianPaymentError::TaxCalculationError("Invalid COFINS rate".to_string()))?;
                    
                    let total_taxes = icms + pis + cofins;
                    let net_amount = gross_amount - total_taxes;
                    
                    let breakdown = BrazilianTaxBreakdown {
                        gross_amount,
                        icms_amount: icms,
                        icms_rate: rust_decimal::Decimal::from_f64(#icms_rate).unwrap(),
                        pis_amount: pis,
                        pis_rate: rust_decimal::Decimal::from_f64(#pis_rate).unwrap(),
                        cofins_amount: cofins,
                        cofins_rate: rust_decimal::Decimal::from_f64(#cofins_rate).unwrap(),
                        total_taxes,
                        net_amount,
                        currency: #config.currency.to_string(),
                    };
                    
                    tracing::debug!(
                        entity = %stringify!(#struct_name),
                        gross_amount = %gross_amount,
                        total_taxes = %total_taxes,
                        net_amount = %net_amount,
                        "Brazilian taxes calculated"
                    );
                    
                    Ok(breakdown)
                } else {
                    Err(BrazilianPaymentError::InvalidAmount("Amount is required for tax calculation".to_string()))
                }
            }
            
            /// Apply tax exemptions based on Brazilian regulations
            pub fn apply_tax_exemptions(&self, exemptions: Vec<TaxExemption>) -> Result<BrazilianTaxBreakdown, BrazilianPaymentError> {
                let mut base_taxes = self.calculate_brazilian_taxes()?;
                
                for exemption in exemptions {
                    match exemption.tax_type {
                        TaxType::Icms => {
                            base_taxes.icms_amount = base_taxes.icms_amount * 
                                (rust_decimal::Decimal::ONE - exemption.exemption_rate);
                        }
                        TaxType::Pis => {
                            base_taxes.pis_amount = base_taxes.pis_amount * 
                                (rust_decimal::Decimal::ONE - exemption.exemption_rate);
                        }
                        TaxType::Cofins => {
                            base_taxes.cofins_amount = base_taxes.cofins_amount * 
                                (rust_decimal::Decimal::ONE - exemption.exemption_rate);
                        }
                    }
                    
                    tracing::info!(
                        entity = %stringify!(#struct_name),
                        tax_type = ?exemption.tax_type,
                        exemption_rate = %exemption.exemption_rate,
                        "Tax exemption applied"
                    );
                }
                
                base_taxes.total_taxes = base_taxes.icms_amount + base_taxes.pis_amount + base_taxes.cofins_amount;
                base_taxes.net_amount = base_taxes.gross_amount - base_taxes.total_taxes;
                
                Ok(base_taxes)
            }
        }
    } else {
        quote! {}
    };
    
    let expanded = quote! {
        impl #struct_name {
            #pix_methods
            #boleto_methods
            #tax_methods
            
            /// Format amount in Brazilian Real (BRL) with proper formatting
            pub fn format_brl_amount(amount: rust_decimal::Decimal) -> String {
                // Format as R$ 1.234,56
                let amount_str = amount.to_string();
                let parts: Vec<&str> = amount_str.split('.').collect();
                
                let integer_part = parts[0];
                let decimal_part = parts.get(1).unwrap_or(&"00");
                
                // Add thousand separators
                let mut formatted_integer = String::new();
                for (i, char) in integer_part.chars().rev().enumerate() {
                    if i > 0 && i % 3 == 0 {
                        formatted_integer.push('.');
                    }
                    formatted_integer.push(char);
                }
                
                let formatted_integer: String = formatted_integer.chars().rev().collect();
                format!("R$ {},{:0<2}", formatted_integer, &decimal_part[..2.min(decimal_part.len())])
            }
            
            /// Parse BRL formatted amount to Decimal
            pub fn parse_brl_amount(formatted: &str) -> Result<rust_decimal::Decimal, BrazilianPaymentError> {
                let cleaned = formatted
                    .replace("R$", "")
                    .replace(" ", "")
                    .replace(".", "")
                    .replace(",", ".");
                
                cleaned.parse::<rust_decimal::Decimal>()
                    .map_err(|e| BrazilianPaymentError::InvalidAmount(
                        format!("Failed to parse BRL amount '{}': {}", formatted, e)
                    ))
            }
            
            /// Validate email format for PIX keys
            fn validate_email(email: &str) -> bool {
                let email_regex = regex::Regex::new(
                    r"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"
                ).unwrap();
                email_regex.is_match(email)
            }
            
            /// Generate payment receipt in Portuguese
            pub fn generate_brazilian_receipt(&self) -> Result<BrazilianReceipt, BrazilianPaymentError> {
                let receipt = BrazilianReceipt {
                    transaction_id: self.get_id().to_string(),
                    date: chrono::Utc::now().with_timezone(&chrono_tz::America::Sao_Paulo),
                    amount: self.get_amount().ok_or(BrazilianPaymentError::InvalidAmount(
                        "Amount is required".to_string()
                    ))?,
                    formatted_amount: Self::format_brl_amount(self.get_amount().unwrap()),
                    payment_method: self.get_payment_method_description(),
                    status: self.get_payment_status_portuguese(),
                    merchant_name: "Pleme Tecnologia Ltda".to_string(),
                    merchant_cnpj: "12.345.678/0001-90".to_string(),
                    customer_document: self.get_customer_document().unwrap_or_default(),
                };
                
                tracing::info!(
                    entity = %stringify!(#struct_name),
                    transaction_id = %receipt.transaction_id,
                    "Brazilian receipt generated"
                );
                
                Ok(receipt)
            }
            
            /// Get payment status in Portuguese
            fn get_payment_status_portuguese(&self) -> String {
                match self.get_status() {
                    PaymentStatus::Pending => "Pendente".to_string(),
                    PaymentStatus::Processing => "Processando".to_string(),
                    PaymentStatus::Completed => "Concluído".to_string(),
                    PaymentStatus::Failed => "Falhou".to_string(),
                    PaymentStatus::Refunded => "Estornado".to_string(),
                    PaymentStatus::Cancelled => "Cancelado".to_string(),
                }
            }
            
            /// Get payment method description in Portuguese
            fn get_payment_method_description(&self) -> String {
                // This would be implemented based on the actual payment method field
                "PIX".to_string() // Default to PIX as primary Brazilian payment method
            }
            
            /// Check if payment complies with Brazilian Central Bank regulations
            pub fn validate_bcb_compliance(&self) -> Result<ComplianceResult, BrazilianPaymentError> {
                let mut issues = Vec::new();
                let mut warnings = Vec::new();
                
                // Check amount limits (PIX has instant transfer limits)
                if let Some(amount) = self.get_amount() {
                    if amount > rust_decimal::Decimal::from(20000) { // R$ 20,000 daily limit
                        warnings.push("Amount exceeds PIX daily limit".to_string());
                    }
                    
                    if amount > rust_decimal::Decimal::from(100000) { // R$ 100,000 monthly limit  
                        issues.push("Amount exceeds PIX monthly limit".to_string());
                    }
                }
                
                // Check business hours for larger amounts
                let now = chrono::Utc::now().with_timezone(&chrono_tz::America::Sao_Paulo);
                let hour = now.hour();
                
                if let Some(amount) = self.get_amount() {
                    if amount > rust_decimal::Decimal::from(1000) && (hour < 6 || hour > 20) {
                        warnings.push("Large amount transfer outside business hours".to_string());
                    }
                }
                
                let compliance = ComplianceResult {
                    is_compliant: issues.is_empty(),
                    issues,
                    warnings,
                    checked_at: chrono::Utc::now(),
                    regulations: vec![
                        "BCB Resolution 4,488/2016".to_string(),
                        "BCB Circular 4,027/2020".to_string(),
                    ],
                };
                
                tracing::info!(
                    entity = %stringify!(#struct_name),
                    is_compliant = %compliance.is_compliant,
                    issues_count = %compliance.issues.len(),
                    warnings_count = %compliance.warnings.len(),
                    "BCB compliance check completed"
                );
                
                Ok(compliance)
            }
            
            // Abstract methods that implementing structs must provide
            fn get_id(&self) -> uuid::Uuid;
            fn get_amount(&self) -> Option<rust_decimal::Decimal>;
            fn get_status(&self) -> PaymentStatus;
            fn set_status(&mut self, status: PaymentStatus);
            fn set_updated_at(&mut self, timestamp: chrono::DateTime<chrono::Utc>);
            fn get_customer_document(&self) -> Option<String>;
        }
        
        /// PIX QR Code data structure
        #[derive(Debug, Clone)]
        pub struct PixData {
            pub merchant_name: &'static str,
            pub merchant_city: &'static str,
            pub transaction_id: String,
            pub amount: rust_decimal::Decimal,
            pub currency: &'static str,
        }
        
        /// PIX key types supported in Brazil
        #[derive(Debug, Clone, Copy, PartialEq, Eq)]
        pub enum PixKeyType {
            Cpf,
            Cnpj,
            Email,
            Phone,
            Random,
        }
        
        /// Boleto bancário data structure
        #[derive(Debug, Clone)]
        pub struct BoletoData {
            pub bank_code: &'static str,
            pub agency: &'static str,
            pub account: &'static str,
            pub wallet: &'static str,
            pub our_number: String,
            pub document_number: String,
            pub due_date: chrono::DateTime<chrono::Utc>,
            pub amount: rust_decimal::Decimal,
            pub payer_name: String,
            pub payer_document: String,
            pub instructions: Vec<String>,
        }
        
        /// Brazilian tax breakdown
        #[derive(Debug, Clone)]
        pub struct BrazilianTaxBreakdown {
            pub gross_amount: rust_decimal::Decimal,
            pub icms_amount: rust_decimal::Decimal,
            pub icms_rate: rust_decimal::Decimal,
            pub pis_amount: rust_decimal::Decimal,
            pub pis_rate: rust_decimal::Decimal,
            pub cofins_amount: rust_decimal::Decimal,
            pub cofins_rate: rust_decimal::Decimal,
            pub total_taxes: rust_decimal::Decimal,
            pub net_amount: rust_decimal::Decimal,
            pub currency: String,
        }
        
        /// Tax exemption configuration
        #[derive(Debug, Clone)]
        pub struct TaxExemption {
            pub tax_type: TaxType,
            pub exemption_rate: rust_decimal::Decimal,
            pub reason: String,
        }
        
        /// Brazilian tax types
        #[derive(Debug, Clone, Copy)]
        pub enum TaxType {
            Icms,  // State tax on goods and services
            Pis,   // Social contribution on revenue  
            Cofins, // Social contribution on revenue
        }
        
        /// Brazilian payment receipt
        #[derive(Debug, Clone)]
        pub struct BrazilianReceipt {
            pub transaction_id: String,
            pub date: chrono::DateTime<chrono_tz::Tz>,
            pub amount: rust_decimal::Decimal,
            pub formatted_amount: String,
            pub payment_method: String,
            pub status: String,
            pub merchant_name: String,
            pub merchant_cnpj: String,
            pub customer_document: String,
        }
        
        /// BCB compliance check result
        #[derive(Debug, Clone)]
        pub struct ComplianceResult {
            pub is_compliant: bool,
            pub issues: Vec<String>,
            pub warnings: Vec<String>,
            pub checked_at: chrono::DateTime<chrono::Utc>,
            pub regulations: Vec<String>,
        }
        
        /// Brazilian payment specific errors
        #[derive(Debug, thiserror::Error)]
        pub enum BrazilianPaymentError {
            #[error("Invalid amount: {0}")]
            InvalidAmount(String),
            
            #[error("Invalid PIX key: {0}")]
            InvalidPixKey(String),
            
            #[error("Invalid PIX data: {0}")]
            InvalidPixData(String),
            
            #[error("Tax calculation error: {0}")]
            TaxCalculationError(String),
            
            #[error("Compliance violation: {0}")]
            ComplianceViolation(String),
        }
        
        /// Generate PIX QR code (placeholder implementation)
        fn generate_pix_qr(data: &PixData) -> Result<String, BrazilianPaymentError> {
            // In a real implementation, this would generate the actual PIX QR code format
            // following the Brazilian Central Bank specifications
            Ok(format!("pix://pay?amount={}&id={}", data.amount, data.transaction_id))
        }
    };
    
    eprintln!("[pleme-codegen] BrazilianPaymentEntity pattern applied to {}", struct_name);
    TokenStream::from(expanded)
}