// Copyright 2017-2021 DERO Project. All rights reserved.
// Use of this source code in any form is governed by RESEARCH license.
// license can be found in the LICENSE file.
// GPG: 0F39 E425 8C65 3947 702A  8234 08B2 0360 A03A 9DE8
//
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package main

import "fmt"
import "time"
import "context"
import "runtime/debug"
import "golang.org/x/time/rate"
import "github.com/deroproject/derohe/rpc"

// rate limiter is deployed, in case RPC is exposed over internet
// someone should not be just giving fake inputs and delay chain syncing
var get_block_limiter = rate.NewLimiter(16.0, 8) // 16 req per sec, burst of 8 req is okay

func (DERO_RPC_APIS) GetBlockTemplate(ctx context.Context, p rpc.GetBlockTemplate_Params) (result rpc.GetBlockTemplate_Result, err error) {

	defer func() { // safety so if anything wrong happens, we return error
		if r := recover(); r != nil {
			err = fmt.Errorf("panic occured. stack trace %s", debug.Stack())
		}
	}()
	/*
			if !get_block_limiter.Allow() { // if rate limiter allows, then add block to chain
				logger.Warnf("Too many get block template requests per sec rejected by chain.")

		                return nil,&jsonrpc.Error{
				Code:    jsonrpc.ErrorCodeInvalidRequest,
				Message: "Too many get block template requests per sec rejected by chain.",
			}


			}
	*/

	// validate address
	miner_address, err := rpc.NewAddress(p.Wallet_Address)
	if err != nil {
		return result, fmt.Errorf("Address could not be parsed, err:%s", err)
	}

	if p.Reserve_size > 255 || p.Reserve_size < 1 {
		return result, fmt.Errorf("Reserve size should be > 0 and < 255")
	}

	bl, block_hashing_blob_hex, block_template_hex, reserved_pos := chain.Create_new_block_template_mining(chain.Get_Top_ID(), *miner_address, int(p.Reserve_size))

	prev_hash := ""
	for i := range bl.Tips {
		prev_hash = prev_hash + bl.Tips[i].String()
	}
	return rpc.GetBlockTemplate_Result{
		Blocktemplate_blob: block_template_hex,
		Blockhashing_blob:  block_hashing_blob_hex,
		Reserved_Offset:    uint64(reserved_pos),
		Expected_reward:    0, // fill in actual reward
		Height:             bl.Height,
		Prev_Hash:          prev_hash,
		Epoch:              uint64(uint64(time.Now().UTC().Unix())), // expiry time of this block
		Difficulty:         chain.Get_Difficulty_At_Tips(bl.Tips).Uint64(),
		Status:             "OK",
	}, nil

}