// 治理投票执行系统
// 自动执行通过的提案

use std::collections::HashMap;

/// 提案执行状态
#[derive(Debug, Clone, PartialEq)]
pub enum ExecutionStatus {
    Pending,      // 待执行
    Executing,    // 执行中
    Completed,    // 已完成
    Failed,       // 执行失败
}

/// 执行结果
#[derive(Debug, Clone)]
pub struct ExecutionResult {
    pub success: bool,
    pub message: String,
    pub timestamp: u64,
}

/// 提案执行记录
#[derive(Debug, Clone)]
pub struct ExecutionRecord {
    pub proposal_id: String,
    pub status: ExecutionStatus,
    pub result: Option<ExecutionResult>,
    pub retry_count: u32,
}

/// 提案执行系统
pub struct ProposalExecutionSystem {
    executions: HashMap<String, ExecutionRecord>,
    stats: ExecutionStats,
}

#[derive(Debug, Clone, Default)]
pub struct ExecutionStats {
    pub total_executions: u64,
    pub successful_executions: u64,
    pub failed_executions: u64,
    pub pending_executions: u64,
}

impl ProposalExecutionSystem {
    pub fn new() -> Self {
        Self {
            executions: HashMap::new(),
            stats: ExecutionStats::default(),
        }
    }

    /// 提交执行请求
    pub fn submit_execution(&mut self, proposal_id: String) {
        let record = ExecutionRecord {
            proposal_id: proposal_id.clone(),
            status: ExecutionStatus::Pending,
            result: None,
            retry_count: 0,
        };

        self.executions.insert(proposal_id, record);
        self.stats.total_executions += 1;
        self.stats.pending_executions += 1;
    }

    /// 执行提案
    pub fn execute_proposal(&mut self, proposal_id: &str) -> Result<ExecutionResult, String> {
        let record = self.executions.get_mut(proposal_id)
            .ok_or("Proposal not found")?;

        if record.status != ExecutionStatus::Pending {
            return Err("Proposal is not in pending status".to_string());
        }

        // 更新状态为执行中
        record.status = ExecutionStatus::Executing;

        // 模拟执行（实际应调用相应的执行逻辑）
        let success = true; // 简化实现

        let result = ExecutionResult {
            success,
            message: if success {
                "Proposal executed successfully".to_string()
            } else {
                "Proposal execution failed".to_string()
            },
            timestamp: 1000,
        };

        // 更新执行记录
        record.status = if success {
            ExecutionStatus::Completed
        } else {
            ExecutionStatus::Failed
        };
        record.result = Some(result.clone());

        // 更新统计
        if success {
            self.stats.successful_executions += 1;
        } else {
            self.stats.failed_executions += 1;
        }
        self.stats.pending_executions = self.stats.pending_executions.saturating_sub(1);

        Ok(result)
    }

    /// 重试失败的执行
    pub fn retry_execution(&mut self, proposal_id: &str) -> Result<(), String> {
        let record = self.executions.get_mut(proposal_id)
            .ok_or("Proposal not found")?;

        if record.status != ExecutionStatus::Failed {
            return Err("Only failed executions can be retried".to_string());
        }

        if record.retry_count >= 3 {
            return Err("Maximum retry count reached".to_string());
        }

        record.status = ExecutionStatus::Pending;
        record.retry_count += 1;
        self.stats.pending_executions += 1;

        Ok(())
    }

    /// 获取执行记录
    pub fn get_execution_record(&self, proposal_id: &str) -> Option<ExecutionRecord> {
        self.executions.get(proposal_id).cloned()
    }

    /// 获取统计信息
    pub fn get_stats(&self) -> ExecutionStats {
        self.stats.clone()
    }
}

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

    #[test]
    fn test_proposal_execution() {
        let mut system = ProposalExecutionSystem::new();

        // 提交执行请求
        system.submit_execution("proposal_001".to_string());

        // 检查待执行状态
        let record = system.get_execution_record("proposal_001").expect("mainnet: handle error");
        assert_eq!(record.status, ExecutionStatus::Pending);

        // 执行提案
        let result = system.execute_proposal("proposal_001").expect("mainnet: handle error");
        assert!(result.success);

        // 检查完成状态
        let record = system.get_execution_record("proposal_001").expect("mainnet: handle error");
        assert_eq!(record.status, ExecutionStatus::Completed);

        // 检查统计
        let stats = system.get_stats();
        assert_eq!(stats.total_executions, 1);
        assert_eq!(stats.successful_executions, 1);
        assert_eq!(stats.pending_executions, 0);
    }
}