// ACC-1155: 多类型资产协议（Multi-Token Protocol）
//
// NAC原生的多类型资产标准，专为RWA资产设计
// 不是ERC-1155的实现，是完全独立的NAC原生协议

use serde::{Deserialize, Serialize};
use std::collections::HashMap;

/// ACC-1155错误类型
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ACC1155Error {
    /// 余额不足
    InsufficientBalance,
    /// 无效的接收地址
    InvalidRecipient,
    /// 无效的金额
    InvalidAmount,
    /// 资产类型不存在
    TokenTypeNotFound,
    /// 未授权操作
    Unauthorized,
}

/// ACC-1155资产状态
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ACC1155State {
    /// 账户余额映射 (account -> token_id -> balance)
    pub balances: HashMap<String, HashMap<String, u128>>,
    /// 操作员授权映射 (owner -> operator -> bool)
    pub operator_approvals: HashMap<String, HashMap<String, bool>>,
    /// 资产URI映射 (token_id -> uri)
    pub token_uris: HashMap<String, String>,
}

/// ACC-1155接口
pub trait ACC1155 {
    /// 获取账户指定资产类型的余额
    fn balance_of(&self, account: &str, token_id: &str) -> u128;

    /// 批量获取余额
    fn balance_of_batch(&self, accounts: &[String], token_ids: &[String]) -> Vec<u128>;

    /// 转移资产
    fn safe_transfer_from(
        &mut self,
        from: &str,
        to: &str,
        token_id: &str,
        amount: u128,
    ) -> Result<(), ACC1155Error>;

    /// 批量转移资产
    fn safe_batch_transfer_from(
        &mut self,
        from: &str,
        to: &str,
        token_ids: &[String],
        amounts: &[u128],
    ) -> Result<(), ACC1155Error>;

    /// 设置操作员授权
    fn set_approval_for_all(
        &mut self,
        owner: &str,
        operator: &str,
        approved: bool,
    ) -> Result<(), ACC1155Error>;

    /// 检查操作员授权
    fn is_approved_for_all(&self, owner: &str, operator: &str) -> bool;

    /// 铸造资产
    fn mint(&mut self, to: &str, token_id: &str, amount: u128) -> Result<(), ACC1155Error>;

    /// 批量铸造资产
    fn mint_batch(
        &mut self,
        to: &str,
        token_ids: &[String],
        amounts: &[u128],
    ) -> Result<(), ACC1155Error>;

    /// 销毁资产
    fn burn(&mut self, from: &str, token_id: &str, amount: u128) -> Result<(), ACC1155Error>;

    /// 获取资产URI
    fn uri(&self, token_id: &str) -> Option<String>;
}

/// ACC-1155标准实现
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ACC1155Token {
    state: ACC1155State,
}

impl ACC1155Token {
    /// 创建新的ACC-1155资产集合
    pub fn new() -> Self {
        Self {
            state: ACC1155State {
                balances: HashMap::new(),
                operator_approvals: HashMap::new(),
                token_uris: HashMap::new(),
            },
        }
    }

    /// 获取状态的可变引用
    pub fn state_mut(&mut self) -> &mut ACC1155State {
        &mut self.state
    }

    /// 获取状态的不可变引用
    pub fn state(&self) -> &ACC1155State {
        &self.state
    }
}

impl Default for ACC1155Token {
    fn default() -> Self {
        Self::new()
    }
}

impl ACC1155 for ACC1155Token {
    fn balance_of(&self, account: &str, token_id: &str) -> u128 {
        self.state
            .balances
            .get(account)
            .and_then(|tokens| tokens.get(token_id))
            .copied()
            .unwrap_or(0)
    }

    fn balance_of_batch(&self, accounts: &[String], token_ids: &[String]) -> Vec<u128> {
        accounts
            .iter()
            .zip(token_ids.iter())
            .map(|(account, token_id)| self.balance_of(account, token_id))
            .collect()
    }

    fn safe_transfer_from(
        &mut self,
        from: &str,
        to: &str,
        token_id: &str,
        amount: u128,
    ) -> Result<(), ACC1155Error> {
        if amount == 0 {
            return Err(ACC1155Error::InvalidAmount);
        }

        let from_balance = self.balance_of(from, token_id);
        if from_balance < amount {
            return Err(ACC1155Error::InsufficientBalance);
        }

        // 更新发送方余额
        self.state
            .balances
            .entry(from.to_string())
            .or_insert_with(HashMap::new)
            .insert(token_id.to_string(), from_balance - amount);

        // 更新接收方余额
        let to_balance = self.balance_of(to, token_id);
        self.state
            .balances
            .entry(to.to_string())
            .or_insert_with(HashMap::new)
            .insert(token_id.to_string(), to_balance + amount);

        Ok(())
    }

    fn safe_batch_transfer_from(
        &mut self,
        from: &str,
        to: &str,
        token_ids: &[String],
        amounts: &[u128],
    ) -> Result<(), ACC1155Error> {
        if token_ids.len() != amounts.len() {
            return Err(ACC1155Error::InvalidAmount);
        }

        for (token_id, &amount) in token_ids.iter().zip(amounts.iter()) {
            self.safe_transfer_from(from, to, token_id, amount)?;
        }

        Ok(())
    }

    fn set_approval_for_all(
        &mut self,
        owner: &str,
        operator: &str,
        approved: bool,
    ) -> Result<(), ACC1155Error> {
        self.state
            .operator_approvals
            .entry(owner.to_string())
            .or_insert_with(HashMap::new)
            .insert(operator.to_string(), approved);

        Ok(())
    }

    fn is_approved_for_all(&self, owner: &str, operator: &str) -> bool {
        self.state
            .operator_approvals
            .get(owner)
            .and_then(|approvals| approvals.get(operator))
            .copied()
            .unwrap_or(false)
    }

    fn mint(&mut self, to: &str, token_id: &str, amount: u128) -> Result<(), ACC1155Error> {
        let to_balance = self.balance_of(to, token_id);
        self.state
            .balances
            .entry(to.to_string())
            .or_insert_with(HashMap::new)
            .insert(token_id.to_string(), to_balance + amount);

        Ok(())
    }

    fn mint_batch(
        &mut self,
        to: &str,
        token_ids: &[String],
        amounts: &[u128],
    ) -> Result<(), ACC1155Error> {
        if token_ids.len() != amounts.len() {
            return Err(ACC1155Error::InvalidAmount);
        }

        for (token_id, &amount) in token_ids.iter().zip(amounts.iter()) {
            self.mint(to, token_id, amount)?;
        }

        Ok(())
    }

    fn burn(&mut self, from: &str, token_id: &str, amount: u128) -> Result<(), ACC1155Error> {
        let from_balance = self.balance_of(from, token_id);
        if from_balance < amount {
            return Err(ACC1155Error::InsufficientBalance);
        }

        self.state
            .balances
            .entry(from.to_string())
            .or_insert_with(HashMap::new)
            .insert(token_id.to_string(), from_balance - amount);

        Ok(())
    }

    fn uri(&self, token_id: &str) -> Option<String> {
        self.state.token_uris.get(token_id).cloned()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_mint_and_balance() {
        let mut token = ACC1155Token::new();
        
        assert!(token.mint("alice", "1", 1000).is_ok());
        assert_eq!(token.balance_of("alice", "1"), 1000);
    }

    #[test]
    fn test_transfer() {
        let mut token = ACC1155Token::new();
        
        token.mint("alice", "1", 1000).unwrap();
        assert!(token.safe_transfer_from("alice", "bob", "1", 500).is_ok());
        
        assert_eq!(token.balance_of("alice", "1"), 500);
        assert_eq!(token.balance_of("bob", "1"), 500);
    }

    #[test]
    fn test_batch_transfer() {
        let mut token = ACC1155Token::new();
        
        token.mint("alice", "1", 1000).unwrap();
        token.mint("alice", "2", 2000).unwrap();
        
        let token_ids = vec!["1".to_string(), "2".to_string()];
        let amounts = vec![500, 1000];
        
        assert!(token
            .safe_batch_transfer_from("alice", "bob", &token_ids, &amounts)
            .is_ok());
        
        assert_eq!(token.balance_of("alice", "1"), 500);
        assert_eq!(token.balance_of("alice", "2"), 1000);
        assert_eq!(token.balance_of("bob", "1"), 500);
        assert_eq!(token.balance_of("bob", "2"), 1000);
    }

    #[test]
    fn test_burn() {
        let mut token = ACC1155Token::new();
        
        token.mint("alice", "1", 1000).unwrap();
        assert!(token.burn("alice", "1", 500).is_ok());
        
        assert_eq!(token.balance_of("alice", "1"), 500);
    }

    #[test]
    fn test_approval() {
        let mut token = ACC1155Token::new();
        
        assert!(token
            .set_approval_for_all("alice", "bob", true)
            .is_ok());
        assert!(token.is_approved_for_all("alice", "bob"));
        
        assert!(token
            .set_approval_for_all("alice", "bob", false)
            .is_ok());
        assert!(!token.is_approved_for_all("alice", "bob"));
    }
}