// Copyright 2015, 2016 Ethcore (UK) Ltd.
// This file is part of Parity.

// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity.  If not, see <http://www.gnu.org/licenses/>.

//! Traces api implementation.

use std::sync::{Weak, Arc};
use jsonrpc_core::*;
use std::collections::BTreeMap;
use util::{H256, U256, FixedHash, Uint};
use serde;
use ethcore::client::{BlockChainClient, CallAnalytics, TransactionID, TraceId};
use ethcore::trace::VMTrace;
use ethcore::miner::MinerService;
use ethcore::state_diff::StateDiff;
use ethcore::account_diff::{Diff, Existance};
use ethcore::transaction::{Transaction as EthTransaction, SignedTransaction, Action};
use v1::traits::Traces;
use v1::types::{TraceFilter, Trace, BlockNumber, Index, CallRequest};

/// Traces api implementation.
pub struct TracesClient<C, M> where C: BlockChainClient, M: MinerService {
	client: Weak<C>,
	miner: Weak<M>,
}

impl<C, M> TracesClient<C, M> where C: BlockChainClient, M: MinerService {
	/// Creates new Traces client.
	pub fn new(client: &Arc<C>, miner: &Arc<M>) -> Self {
		TracesClient {
			client: Arc::downgrade(client),
			miner: Arc::downgrade(miner),
		}
	}

	// TODO: share with eth.rs
	fn sign_call(&self, request: CallRequest) -> Result<SignedTransaction, Error> {
		let client = take_weak!(self.client);
		let miner = take_weak!(self.miner);
		let from = request.from.unwrap_or(0.into());
		Ok(EthTransaction {
			nonce: request.nonce.unwrap_or_else(|| client.latest_nonce(&from)),
			action: request.to.map_or(Action::Create, Action::Call),
			gas: request.gas.unwrap_or(50_000_000.into()),
			gas_price: request.gas_price.unwrap_or_else(|| miner.sensible_gas_price()),
			value: request.value.unwrap_or(0.into()),
			data: request.data.map_or_else(Vec::new, |d| d.to_vec())
		}.fake_sign(from))
	}
}

fn vm_trace_to_object(t: &VMTrace) -> Value {
	let mut ret = BTreeMap::new();
	ret.insert("code".to_owned(), to_value(&t.code).unwrap());

	let mut subs = t.subs.iter();
	let mut next_sub = subs.next();

	let ops = t.operations
		.iter()
		.enumerate()
		.map(|(i, op)| {
			let mut m = map![
				"pc".to_owned() => to_value(&op.pc).unwrap(),
				"cost".to_owned() => match op.gas_cost <= U256::from(!0u64) {
					true => to_value(&op.gas_cost.low_u64()),
					false => to_value(&op.gas_cost),
				}.unwrap()
			];
			if let Some(ref ex) = op.executed {
				let mut em = map![
					"used".to_owned() => to_value(&ex.gas_used.low_u64()).unwrap(),
					"push".to_owned() => to_value(&ex.stack_push).unwrap()
				];
				if let Some(ref md) = ex.mem_diff {
					em.insert("mem".to_owned(), Value::Object(map![
						"off".to_owned() => to_value(&md.offset).unwrap(),
						"data".to_owned() => to_value(&md.data).unwrap()
					]));
				}
				if let Some(ref sd) = ex.store_diff {
					em.insert("store".to_owned(), Value::Object(map![
						"key".to_owned() => to_value(&sd.location).unwrap(),
						"val".to_owned() => to_value(&sd.value).unwrap()
					]));
				}
				m.insert("ex".to_owned(), Value::Object(em));
			}
			if next_sub.is_some() && next_sub.unwrap().parent_step == i {
				m.insert("sub".to_owned(), vm_trace_to_object(next_sub.unwrap()));
				next_sub = subs.next();
			}
			Value::Object(m)
		})
		.collect::<Vec<_>>();
	ret.insert("ops".to_owned(), Value::Array(ops));
	Value::Object(ret)
}

fn diff_to_object<T>(d: &Diff<T>) -> Value where T: serde::Serialize + Eq {
	let mut ret = BTreeMap::new();
	match *d {
		Diff::Same => {
			ret.insert("diff".to_owned(), Value::String("=".to_owned()));
		}
		Diff::Born(ref x) => {
			ret.insert("diff".to_owned(), Value::String("+".to_owned()));
			ret.insert("+".to_owned(), to_value(x).unwrap());
		}
		Diff::Died(ref x) => {
			ret.insert("diff".to_owned(), Value::String("-".to_owned()));
			ret.insert("-".to_owned(), to_value(x).unwrap());
		}
		Diff::Changed(ref from, ref to) => {
			ret.insert("diff".to_owned(), Value::String("*".to_owned()));
			ret.insert("-".to_owned(), to_value(from).unwrap());
			ret.insert("+".to_owned(), to_value(to).unwrap());
		}
	};
	Value::Object(ret)
}

fn state_diff_to_object(t: &StateDiff) -> Value {
	Value::Object(t.iter().map(|(address, account)| {
		(address.hex(), Value::Object(map![
			"existance".to_owned() => Value::String(match account.existance() {
				Existance::Born => "+",
				Existance::Alive => ".",
				Existance::Died => "-",
			}.to_owned()),
			"balance".to_owned() => diff_to_object(&account.balance),
			"nonce".to_owned() => diff_to_object(&account.nonce),
			"code".to_owned() => diff_to_object(&account.code),
			"storage".to_owned() => Value::Object(account.storage.iter().map(|(key, val)| {
				(key.hex(), diff_to_object(&val))
			}).collect::<BTreeMap<_, _>>())
		]))
	}).collect::<BTreeMap<_, _>>())
}

impl<C, M> Traces for TracesClient<C, M> where C: BlockChainClient + 'static, M: MinerService + 'static {
	fn filter(&self, params: Params) -> Result<Value, Error> {
		from_params::<(TraceFilter,)>(params)
			.and_then(|(filter, )| {
				let client = take_weak!(self.client);
				let traces = client.filter_traces(filter.into());
				let traces = traces.map_or_else(Vec::new, |traces| traces.into_iter().map(Trace::from).collect());
				to_value(&traces)
			})
	}

	fn block_traces(&self, params: Params) -> Result<Value, Error> {
		from_params::<(BlockNumber,)>(params)
			.and_then(|(block_number,)| {
				let client = take_weak!(self.client);
				let traces = client.block_traces(block_number.into());
				let traces = traces.map_or_else(Vec::new, |traces| traces.into_iter().map(Trace::from).collect());
				to_value(&traces)
			})
	}

	fn transaction_traces(&self, params: Params) -> Result<Value, Error> {
		from_params::<(H256,)>(params)
			.and_then(|(transaction_hash,)| {
				let client = take_weak!(self.client);
				let traces = client.transaction_traces(TransactionID::Hash(transaction_hash));
				let traces = traces.map_or_else(Vec::new, |traces| traces.into_iter().map(Trace::from).collect());
				to_value(&traces)
			})
	}

	fn trace(&self, params: Params) -> Result<Value, Error> {
		from_params::<(H256, Vec<Index>)>(params)
			.and_then(|(transaction_hash, address)| {
				let client = take_weak!(self.client);
				let id = TraceId {
					transaction: TransactionID::Hash(transaction_hash),
					address: address.into_iter().map(|i| i.value()).collect()
				};
				let trace = client.trace(id);
				let trace = trace.map(Trace::from);
				to_value(&trace)
			})
	}

	fn vm_trace_call(&self, params: Params) -> Result<Value, Error> {
		trace!(target: "jsonrpc", "vm_trace_call: {:?}", params);
		from_params(params)
			.and_then(|(request,)| {
				let signed = try!(self.sign_call(request));
				let r = take_weak!(self.client).call(&signed, CallAnalytics{ vm_tracing: true, state_diffing: false });
				if let Ok(executed) = r {
					if let Some(vm_trace) = executed.vm_trace {
						return Ok(vm_trace_to_object(&vm_trace));
					}
				}
				Ok(Value::Null)
			})
	}

	fn state_diff_call(&self, params: Params) -> Result<Value, Error> {
		trace!(target: "jsonrpc", "state_diff_call: {:?}", params);
		from_params(params)
			.and_then(|(request,)| {
				let signed = try!(self.sign_call(request));
				let r = take_weak!(self.client).call(&signed, CallAnalytics{ vm_tracing: false, state_diffing: true });
				if let Ok(executed) = r {
					if let Some(state_diff) = executed.state_diff {
						return Ok(state_diff_to_object(&state_diff));
					}
				}
				Ok(Value::Null)
			})
	}
}