// ACC-Governance: 资产治理协议（Governance Protocol）
//
// NAC原生的资产治理标准，用于去中心化治理和投票
// 100% NAC原生协议，不是任何现有标准的实现

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

/// 提案状态
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ProposalStatus {
    /// 草稿
    Draft,
    /// 活跃（投票中）
    Active,
    /// 已通过
    Passed,
    /// 已拒绝
    Rejected,
    /// 已执行
    Executed,
    /// 已取消
    Cancelled,
}

/// 投票选项
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum VoteOption {
    /// 赞成
    For,
    /// 反对
    Against,
    /// 弃权
    Abstain,
}

/// 提案类型
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum ProposalType {
    /// 参数修改
    ParameterChange,
    /// 资金分配
    FundingAllocation,
    /// 协议升级
    ProtocolUpgrade,
    /// 资产管理
    AssetManagement,
    /// 其他
    Other(String),
}

/// 治理提案
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GovernanceProposal {
    /// 提案ID
    pub proposal_id: String,
    /// 资产ID
    pub asset_id: String,
    /// 提案人地址
    pub proposer: String,
    /// 提案类型
    pub proposal_type: ProposalType,
    /// 提案标题
    pub title: String,
    /// 提案描述
    pub description: String,
    /// 提案状态
    pub status: ProposalStatus,
    /// 创建时间
    pub created_at: u64,
    /// 投票开始时间
    pub voting_start: u64,
    /// 投票结束时间
    pub voting_end: u64,
    /// 执行时间
    pub executed_at: Option<u64>,
    /// 赞成票数
    pub votes_for: u128,
    /// 反对票数
    pub votes_against: u128,
    /// 弃权票数
    pub votes_abstain: u128,
    /// 通过阈值（百分比，如5000表示50%）
    pub quorum_threshold: u16,
    /// 投票记录 (voter -> VoteOption)
    pub votes: HashMap<String, VoteOption>,
}

/// 投票记录
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct VoteRecord {
    /// 投票ID
    pub vote_id: String,
    /// 提案ID
    pub proposal_id: String,
    /// 投票人地址
    pub voter: String,
    /// 投票选项
    pub option: VoteOption,
    /// 投票权重
    pub voting_power: u128,
    /// 投票时间
    pub voted_at: u64,
}

/// 治理错误类型
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum GovernanceError {
    /// 提案不存在
    ProposalNotFound,
    /// 提案已存在
    ProposalAlreadyExists,
    /// 投票未开始
    VotingNotStarted,
    /// 投票已结束
    VotingEnded,
    /// 已投票
    AlreadyVoted,
    /// 提案未通过
    ProposalNotPassed,
    /// 提案已执行
    ProposalAlreadyExecuted,
    /// 未授权操作
    Unauthorized,
    /// 无效的投票权重
    InvalidVotingPower,
}

/// 治理状态
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GovernanceState {
    /// 提案映射 (proposal_id -> GovernanceProposal)
    pub proposals: HashMap<String, GovernanceProposal>,
    /// 资产提案列表 (asset_id -> [proposal_ids])
    pub asset_proposals: HashMap<String, Vec<String>>,
    /// 提案人提案列表 (proposer -> [proposal_ids])
    pub proposer_proposals: HashMap<String, Vec<String>>,
    /// 投票记录 (vote_id -> VoteRecord)
    pub vote_records: HashMap<String, VoteRecord>,
}

/// ACC-Governance接口
pub trait ACCGovernance {
    /// 创建提案
    fn create_proposal(&mut self, proposal: GovernanceProposal) -> Result<(), GovernanceError>;

    /// 获取提案
    fn get_proposal(&self, proposal_id: &str) -> Result<GovernanceProposal, GovernanceError>;

    /// 投票
    fn vote(
        &mut self,
        proposal_id: &str,
        voter: &str,
        option: VoteOption,
        voting_power: u128,
    ) -> Result<(), GovernanceError>;

    /// 执行提案
    fn execute_proposal(&mut self, proposal_id: &str) -> Result<(), GovernanceError>;

    /// 取消提案
    fn cancel_proposal(&mut self, proposal_id: &str) -> Result<(), GovernanceError>;

    /// 获取提案结果
    fn get_proposal_result(&self, proposal_id: &str) -> Result<(u128, u128, u128), GovernanceError>;

    /// 检查提案是否通过
    fn is_proposal_passed(&self, proposal_id: &str) -> bool;

    /// 获取资产的提案列表
    fn get_asset_proposals(&self, asset_id: &str) -> Vec<GovernanceProposal>;

    /// 获取提案人的提案列表
    fn get_proposer_proposals(&self, proposer: &str) -> Vec<GovernanceProposal>;

    /// 获取投票记录
    fn get_vote_record(&self, vote_id: &str) -> Result<VoteRecord, GovernanceError>;

    /// 获取活跃提案列表
    fn get_active_proposals(&self) -> Vec<GovernanceProposal>;

    /// 更新提案状态
    fn update_proposal_status(
        &mut self,
        proposal_id: &str,
        status: ProposalStatus,
    ) -> Result<(), GovernanceError>;
}

/// ACC-Governance标准实现
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GovernanceToken {
    state: GovernanceState,
}

impl GovernanceToken {
    /// 创建新的治理管理器
    pub fn new() -> Self {
        Self {
            state: GovernanceState {
                proposals: HashMap::new(),
                asset_proposals: HashMap::new(),
                proposer_proposals: HashMap::new(),
                vote_records: HashMap::new(),
            },
        }
    }

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

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

    /// 检查投票是否有效
    fn is_voting_active(&self, proposal: &GovernanceProposal) -> bool {
        let now = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();
        now >= proposal.voting_start && now <= proposal.voting_end
    }
}

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

impl ACCGovernance for GovernanceToken {
    fn create_proposal(&mut self, mut proposal: GovernanceProposal) -> Result<(), GovernanceError> {
        // 检查提案是否已存在
        if self.state.proposals.contains_key(&proposal.proposal_id) {
            return Err(GovernanceError::ProposalAlreadyExists);
        }

        let now = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        proposal.created_at = now;
        proposal.status = ProposalStatus::Active;
        proposal.votes_for = 0;
        proposal.votes_against = 0;
        proposal.votes_abstain = 0;

        let proposal_id = proposal.proposal_id.clone();
        let asset_id = proposal.asset_id.clone();
        let proposer = proposal.proposer.clone();

        // 保存提案
        self.state
            .proposals
            .insert(proposal_id.clone(), proposal);

        // 更新资产提案列表
        self.state
            .asset_proposals
            .entry(asset_id)
            .or_insert_with(Vec::new)
            .push(proposal_id.clone());

        // 更新提案人提案列表
        self.state
            .proposer_proposals
            .entry(proposer)
            .or_insert_with(Vec::new)
            .push(proposal_id);

        Ok(())
    }

    fn get_proposal(&self, proposal_id: &str) -> Result<GovernanceProposal, GovernanceError> {
        self.state
            .proposals
            .get(proposal_id)
            .cloned()
            .ok_or(GovernanceError::ProposalNotFound)
    }

    fn vote(
        &mut self,
        proposal_id: &str,
        voter: &str,
        option: VoteOption,
        voting_power: u128,
    ) -> Result<(), GovernanceError> {
        let mut proposal = self.get_proposal(proposal_id)?;

        // 检查投票是否有效
        if !self.is_voting_active(&proposal) {
            let now = std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs();
            if now < proposal.voting_start {
                return Err(GovernanceError::VotingNotStarted);
            } else {
                return Err(GovernanceError::VotingEnded);
            }
        }

        // 检查是否已投票
        if proposal.votes.contains_key(voter) {
            return Err(GovernanceError::AlreadyVoted);
        }

        // 检查投票权重
        if voting_power == 0 {
            return Err(GovernanceError::InvalidVotingPower);
        }

        let now = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        // 更新投票统计
        match option {
            VoteOption::For => proposal.votes_for += voting_power,
            VoteOption::Against => proposal.votes_against += voting_power,
            VoteOption::Abstain => proposal.votes_abstain += voting_power,
        }

        // 记录投票
        proposal.votes.insert(voter.to_string(), option.clone());

        // 保存提案
        self.state
            .proposals
            .insert(proposal_id.to_string(), proposal);

        // 创建投票记录
        let vote_id = format!("{}_{}", proposal_id, voter);
        let vote_record = VoteRecord {
            vote_id: vote_id.clone(),
            proposal_id: proposal_id.to_string(),
            voter: voter.to_string(),
            option,
            voting_power,
            voted_at: now,
        };

        self.state.vote_records.insert(vote_id, vote_record);

        Ok(())
    }

    fn execute_proposal(&mut self, proposal_id: &str) -> Result<(), GovernanceError> {
        let mut proposal = self.get_proposal(proposal_id)?;

        // 检查提案是否通过
        if !self.is_proposal_passed(proposal_id) {
            return Err(GovernanceError::ProposalNotPassed);
        }

        // 检查提案是否已执行
        if proposal.status == ProposalStatus::Executed {
            return Err(GovernanceError::ProposalAlreadyExecuted);
        }

        let now = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        proposal.status = ProposalStatus::Executed;
        proposal.executed_at = Some(now);

        self.state
            .proposals
            .insert(proposal_id.to_string(), proposal);

        Ok(())
    }

    fn cancel_proposal(&mut self, proposal_id: &str) -> Result<(), GovernanceError> {
        let mut proposal = self.get_proposal(proposal_id)?;

        if proposal.status == ProposalStatus::Executed {
            return Err(GovernanceError::ProposalAlreadyExecuted);
        }

        proposal.status = ProposalStatus::Cancelled;

        self.state
            .proposals
            .insert(proposal_id.to_string(), proposal);

        Ok(())
    }

    fn get_proposal_result(&self, proposal_id: &str) -> Result<(u128, u128, u128), GovernanceError> {
        let proposal = self.get_proposal(proposal_id)?;
        Ok((
            proposal.votes_for,
            proposal.votes_against,
            proposal.votes_abstain,
        ))
    }

    fn is_proposal_passed(&self, proposal_id: &str) -> bool {
        if let Ok(proposal) = self.get_proposal(proposal_id) {
            let total_votes = proposal.votes_for + proposal.votes_against + proposal.votes_abstain;
            if total_votes == 0 {
                return false;
            }

            let approval_rate = (proposal.votes_for * 10000 / total_votes) as u16;
            approval_rate >= proposal.quorum_threshold
        } else {
            false
        }
    }

    fn get_asset_proposals(&self, asset_id: &str) -> Vec<GovernanceProposal> {
        self.state
            .asset_proposals
            .get(asset_id)
            .map(|proposal_ids| {
                proposal_ids
                    .iter()
                    .filter_map(|id| self.state.proposals.get(id).cloned())
                    .collect()
            })
            .unwrap_or_default()
    }

    fn get_proposer_proposals(&self, proposer: &str) -> Vec<GovernanceProposal> {
        self.state
            .proposer_proposals
            .get(proposer)
            .map(|proposal_ids| {
                proposal_ids
                    .iter()
                    .filter_map(|id| self.state.proposals.get(id).cloned())
                    .collect()
            })
            .unwrap_or_default()
    }

    fn get_vote_record(&self, vote_id: &str) -> Result<VoteRecord, GovernanceError> {
        self.state
            .vote_records
            .get(vote_id)
            .cloned()
            .ok_or(GovernanceError::ProposalNotFound)
    }

    fn get_active_proposals(&self) -> Vec<GovernanceProposal> {
        self.state
            .proposals
            .values()
            .filter(|proposal| proposal.status == ProposalStatus::Active)
            .cloned()
            .collect()
    }

    fn update_proposal_status(
        &mut self,
        proposal_id: &str,
        status: ProposalStatus,
    ) -> Result<(), GovernanceError> {
        let mut proposal = self.get_proposal(proposal_id)?;
        proposal.status = status;
        self.state
            .proposals
            .insert(proposal_id.to_string(), proposal);
        Ok(())
    }
}

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

    fn create_test_proposal() -> GovernanceProposal {
        let now = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        GovernanceProposal {
            proposal_id: "PROP-001".to_string(),
            asset_id: "RWA-001".to_string(),
            proposer: "alice".to_string(),
            proposal_type: ProposalType::ParameterChange,
            title: "Test Proposal".to_string(),
            description: "This is a test proposal".to_string(),
            status: ProposalStatus::Active,
            created_at: now,
            voting_start: now - 3600, // 1小时前开始
            voting_end: now + 86400 * 7, // 7天后结束
            executed_at: None,
            votes_for: 0,
            votes_against: 0,
            votes_abstain: 0,
            quorum_threshold: 5000, // 50%
            votes: HashMap::new(),
        }
    }

    #[test]
    fn test_create_proposal() {
        let mut governance = GovernanceToken::new();
        let proposal = create_test_proposal();
        assert!(governance.create_proposal(proposal).is_ok());
    }

    #[test]
    fn test_vote() {
        let mut governance = GovernanceToken::new();
        let proposal = create_test_proposal();
        governance.create_proposal(proposal).unwrap();

        assert!(governance
            .vote("PROP-001", "bob", VoteOption::For, 1000)
            .is_ok());

        let (votes_for, _, _) = governance.get_proposal_result("PROP-001").unwrap();
        assert_eq!(votes_for, 1000);
    }

    #[test]
    fn test_is_proposal_passed() {
        let mut governance = GovernanceToken::new();
        let proposal = create_test_proposal();
        governance.create_proposal(proposal).unwrap();

        governance
            .vote("PROP-001", "bob", VoteOption::For, 6000)
            .unwrap();
        governance
            .vote("PROP-001", "charlie", VoteOption::Against, 4000)
            .unwrap();

        assert!(governance.is_proposal_passed("PROP-001"));
    }

    #[test]
    fn test_execute_proposal() {
        let mut governance = GovernanceToken::new();
        let proposal = create_test_proposal();
        governance.create_proposal(proposal).unwrap();

        governance
            .vote("PROP-001", "bob", VoteOption::For, 6000)
            .unwrap();
        governance
            .vote("PROP-001", "charlie", VoteOption::Against, 4000)
            .unwrap();

        assert!(governance.execute_proposal("PROP-001").is_ok());
        assert_eq!(
            governance.get_proposal("PROP-001").unwrap().status,
            ProposalStatus::Executed
        );
    }

    #[test]
    fn test_cancel_proposal() {
        let mut governance = GovernanceToken::new();
        let proposal = create_test_proposal();
        governance.create_proposal(proposal).unwrap();

        assert!(governance.cancel_proposal("PROP-001").is_ok());
        assert_eq!(
            governance.get_proposal("PROP-001").unwrap().status,
            ProposalStatus::Cancelled
        );
    }
}