use anyhow::Result;
use solana_hash::Hash;
use solana_sdk::{
    instruction::Instruction, message::AddressLookupTableAccount, pubkey::Pubkey,
    signature::Keypair, signature::Signature,
};
use std::{sync::Arc, time::{Duration, Instant}};
#[allow(unused_imports)]
use tracing::{info, trace, warn};

use crate::{
    common::{nonce_cache::DurableNonceInfo, GasFeeStrategy, SolanaRpcClient},
    perf::syscall_bypass::SystemCallBypassManager,
    swqos::common::poll_transaction_confirmation,
    trading::core::{
        async_executor::execute_parallel,
        execution::{InstructionProcessor, Prefetch},
        traits::TradeExecutor,
    },
    trading::MiddlewareManager,
};
use once_cell::sync::Lazy;
use crate::swqos::TradeType;
use super::{params::SwapParams, traits::InstructionBuilder};

/// Global syscall bypass manager (reserved for future time/IO optimizations).
/// 全局系统调用绕过管理器（预留，后续可接入时间/IO 等优化）。
#[allow(dead_code)]
static SYSCALL_BYPASS: Lazy<SystemCallBypassManager> = Lazy::new(|| {
    use crate::perf::syscall_bypass::SyscallBypassConfig;
    SystemCallBypassManager::new(SyscallBypassConfig::default())
        .expect("Failed to create SystemCallBypassManager")
});

/// Generic trade executor implementation
pub struct GenericTradeExecutor {
    instruction_builder: Arc<dyn InstructionBuilder>,
    protocol_name: &'static str,
}

impl GenericTradeExecutor {
    pub fn new(
        instruction_builder: Arc<dyn InstructionBuilder>,
        protocol_name: &'static str,
    ) -> Self {
        Self { instruction_builder, protocol_name }
    }
}

#[async_trait::async_trait]
impl TradeExecutor for GenericTradeExecutor {
    async fn swap(&self, params: SwapParams) -> Result<(bool, Vec<Signature>, Option<anyhow::Error>)> {
        // Sample total start only when logging or simulate. 仅在有日志或 simulate 时取起点。
        let total_start = (params.log_enabled || params.simulate).then(Instant::now);
        let timing_start_us: Option<i64> = if params.log_enabled {
            Some(params.grpc_recv_us.unwrap_or_else(crate::common::clock::now_micros))
        } else {
            None
        };

        let is_buy = params.trade_type == TradeType::Buy || params.trade_type == TradeType::CreateAndBuy;

        Prefetch::keypair(&params.payer);

        // Time build only when log_enabled to avoid cold-path syscalls. 仅 log_enabled 时计时，减少冷路径 syscall。
        let build_start = params.log_enabled.then(Instant::now);
        let instructions = if is_buy {
            self.instruction_builder.build_buy_instructions(&params).await?
        } else {
            self.instruction_builder.build_sell_instructions(&params).await?
        };
        let build_elapsed = build_start.map(|s| s.elapsed()).unwrap_or(Duration::ZERO);

        InstructionProcessor::preprocess(&instructions)?;

        let final_instructions = match &params.middleware_manager {
            Some(middleware_manager) => middleware_manager
                .apply_middlewares_process_protocol_instructions(
                    instructions,
                    self.protocol_name.to_string(),
                    is_buy,
                )?,
            None => instructions,
        };

        let before_submit_elapsed = total_start.as_ref().map(|s| s.elapsed()).unwrap_or(Duration::ZERO);

        if params.simulate {
            let send_start = crate::common::sdk_log::sdk_log_enabled().then(Instant::now);
            let result = simulate_transaction(
                params.rpc,
                params.payer,
                final_instructions,
                params.address_lookup_table_account,
                params.recent_blockhash,
                params.durable_nonce,
                params.middleware_manager,
                self.protocol_name,
                is_buy,
                if is_buy { true } else { params.with_tip },
                params.gas_fee_strategy,
            )
            .await;
            let send_elapsed = send_start.map(|s| s.elapsed()).unwrap_or(Duration::ZERO);
            let total_elapsed = total_start.as_ref().map(|s| s.elapsed()).unwrap_or(Duration::ZERO);

            if crate::common::sdk_log::sdk_log_enabled() {
                let dir = if is_buy { "Buy" } else { "Sell" };
                println!(" [SDK] {} timing(sim) build_instructions: {:.2}ms before_submit: {:.2}ms simulate: {:.2}ms total: {:.2}ms", dir, build_elapsed.as_secs_f64() * 1000.0, before_submit_elapsed.as_secs_f64() * 1000.0, send_elapsed.as_secs_f64() * 1000.0, total_elapsed.as_secs_f64() * 1000.0);
            }

            return result;
        }

        let need_confirm = params.wait_transaction_confirmed;
        let send_start = params.log_enabled.then(Instant::now);
        let result = execute_parallel(
            &params.swqos_clients,
            params.payer,
            params.rpc.clone(),
            final_instructions,
            params.address_lookup_table_account,
            params.recent_blockhash,
            params.durable_nonce,
            params.middleware_manager,
            self.protocol_name,
            is_buy,
            false, // submit only here; confirmation and log timing handled below
            if is_buy { true } else { params.with_tip },
            params.gas_fee_strategy,
            params.use_core_affinity,
        )
        .await;
        let send_elapsed = send_start.map(|s| s.elapsed()).unwrap_or(Duration::ZERO);

        if params.log_enabled && crate::common::sdk_log::sdk_log_enabled() {
            let dir = if is_buy { "Buy" } else { "Sell" };
            let build_ms = build_elapsed.as_secs_f64() * 1000.0;
            let before_ms = before_submit_elapsed.as_secs_f64() * 1000.0;
            let send_ms = send_elapsed.as_secs_f64() * 1000.0;
            if let Some(start_us) = timing_start_us {
                let now_us = crate::common::clock::now_micros();
                let start_to_submit_us = (now_us - start_us).max(0);
                println!(" [SDK] {} timing(after_submit) build_instructions: {:.2}ms before_submit: {:.2}ms submit: {:.2}ms start_to_submit: {} μs", dir, build_ms, before_ms, send_ms, start_to_submit_us);
            } else {
                println!(" [SDK] {} timing(after_submit) build_instructions: {:.2}ms before_submit: {:.2}ms submit: {:.2}ms", dir, build_ms, before_ms, send_ms);
            }
        }

        let result = if need_confirm {
            let (ok, sigs, err) = match &result {
                Ok((success, signatures, last_error)) => (
                    *success,
                    signatures.clone(),
                    last_error.as_ref().map(|e| anyhow::anyhow!("{}", e)),
                ),
                Err(e) => (false, vec![], Some(anyhow::anyhow!("{}", e))),
            };
            let first_sig = sigs.first().copied();
            let confirm_result = if let (Some(rpc), Some(sig)) = (params.rpc.as_ref(), first_sig) {
                let confirm_start = (params.log_enabled && crate::common::sdk_log::sdk_log_enabled()).then(Instant::now);
                let poll_res = poll_transaction_confirmation(rpc, sig, true).await;
                let confirm_elapsed = confirm_start.map(|s| s.elapsed()).unwrap_or(Duration::ZERO);
                if params.log_enabled && crate::common::sdk_log::sdk_log_enabled() {
                    let dir = if is_buy { "Buy" } else { "Sell" };
                    let confirm_ms = confirm_elapsed.as_secs_f64() * 1000.0;
                    let total_ms = total_start.as_ref().map(|s| s.elapsed()).unwrap_or(Duration::ZERO).as_secs_f64() * 1000.0;
                    println!(" [SDK] {} timing(after_confirm) confirm: {:.2}ms total: {:.2}ms", dir, confirm_ms, total_ms);
                }
                match poll_res {
                    Ok(_) => (true, sigs, None),
                    Err(e) => (false, sigs, Some(e)),
                }
            } else {
                (ok, sigs, err)
            };
            Ok(confirm_result)
        } else {
            if params.log_enabled && crate::common::sdk_log::sdk_log_enabled() {
                let total_ms = total_start.as_ref().map(|s| s.elapsed()).unwrap_or(Duration::ZERO).as_secs_f64() * 1000.0;
                let dir = if is_buy { "Buy" } else { "Sell" };
                println!(" [SDK] {} timing total: {:.2}ms", dir, total_ms);
            }
            result
        };

        result
    }

    fn protocol_name(&self) -> &'static str {
        self.protocol_name
    }
}

/// Simulate mode: single RPC simulation, returns Vec<Signature> for API consistency.
/// 模拟模式：单次 RPC 模拟，返回 Vec<Signature> 以与 API 一致。
async fn simulate_transaction(
    rpc: Option<Arc<SolanaRpcClient>>,
    payer: Arc<Keypair>,
    instructions: Vec<Instruction>,
    address_lookup_table_account: Option<AddressLookupTableAccount>,
    recent_blockhash: Option<Hash>,
    durable_nonce: Option<DurableNonceInfo>,
    middleware_manager: Option<Arc<MiddlewareManager>>,
    protocol_name: &'static str,
    is_buy: bool,
    with_tip: bool,
    gas_fee_strategy: GasFeeStrategy,
) -> Result<(bool, Vec<Signature>, Option<anyhow::Error>)> {
    use crate::trading::common::build_transaction;
    use solana_client::rpc_config::RpcSimulateTransactionConfig;
    use solana_commitment_config::CommitmentLevel;
    use solana_transaction_status::UiTransactionEncoding;

    let rpc = rpc.ok_or_else(|| anyhow::anyhow!("RPC client is required for simulation"))?;

    // Get gas fee strategy for simulation (use Default swqos type)
    let trade_type =
        if is_buy { crate::swqos::TradeType::Buy } else { crate::swqos::TradeType::Sell };
    let gas_fee_configs = gas_fee_strategy.get_strategies(trade_type);

    let default_config = gas_fee_configs
        .iter()
        .find(|config| config.0 == crate::swqos::SwqosType::Default)
        .ok_or_else(|| anyhow::anyhow!("No default gas fee strategy found"))?;

    let tip = if with_tip { default_config.2.tip } else { 0.0 };
    let unit_limit = default_config.2.cu_limit;
    let unit_price = default_config.2.cu_price;

    // Build transaction for simulation
    let transaction = build_transaction(
        payer.clone(),
        Some(rpc.clone()),
        unit_limit,
        unit_price,
        &instructions,
        address_lookup_table_account,
        recent_blockhash,
        middleware_manager,
        protocol_name,
        is_buy,
        false, // simulate doesn't need tip instruction
        &Pubkey::default(),
        tip,
        durable_nonce,
    )
    .await?;

    // Simulate the transaction
    use solana_commitment_config::CommitmentConfig;
    let simulate_result = rpc
        .simulate_transaction_with_config(
            &transaction,
            RpcSimulateTransactionConfig {
                sig_verify: false,               // Don't verify signature during simulation for speed
                replace_recent_blockhash: false, // Use actual blockhash from transaction
                commitment: Some(CommitmentConfig {
                    commitment: CommitmentLevel::Processed, // Use Processed level to get latest state
                }),
                encoding: Some(UiTransactionEncoding::Base64), // Base64 encoding
                accounts: None,           // Don't return specific account states (can be specified if needed)
                min_context_slot: None,   // Don't specify minimum context slot
                inner_instructions: true, // Enable inner instructions for debugging and detailed execution flow
            },
        )
        .await?;

    let signature = transaction
        .signatures
        .first()
        .ok_or_else(|| anyhow::anyhow!("Transaction has no signatures"))?
        .clone();

    if let Some(err) = simulate_result.value.err {
        #[cfg(feature = "perf-trace")]
        {
            warn!(target: "sol_trade_sdk", "[Simulation Failed] error={:?} signature={:?}", err, signature);
            if let Some(logs) = &simulate_result.value.logs {
                trace!(target: "sol_trade_sdk", "Transaction logs: {:?}", logs);
            }
            if let Some(units_consumed) = simulate_result.value.units_consumed {
                trace!(target: "sol_trade_sdk", "Compute Units Consumed: {}", units_consumed);
            }
        }
        return Ok((false, vec![signature], Some(anyhow::anyhow!("{:?}", err))));
    }

    // Simulation succeeded
    #[cfg(feature = "perf-trace")]
    {
        info!(target: "sol_trade_sdk", "[Simulation Succeeded] signature={:?}", signature);
        if let Some(units_consumed) = simulate_result.value.units_consumed {
            trace!(target: "sol_trade_sdk", "Compute Units Consumed: {}", units_consumed);
        }
        if let Some(logs) = &simulate_result.value.logs {
            trace!(target: "sol_trade_sdk", "Transaction logs: {:?}", logs);
        }
    }

    Ok((true, vec![signature], None))
}