package core

import (
	"context"
	"errors"
	"github.com/matchsystems/werr"
	"mic-wallet/common"
	"time"
)

type IBlocksCreator interface {
	Run(ctx context.Context) error
	WriteTx(opts *common.NewTxOpts) error
	// GetTx Searches for tx in every block
	GetTx(block int64, hash string) *common.NewTxOpts
	GetTxs() []*common.NewTxOpts
}

type BlocksCreator struct {
	blocks        map[int64]*Block
	commiter      IBlocksCommiter
	prevBlockHash []byte
}

func NewBlocksCreator(commiter IBlocksCommiter) *BlocksCreator {
	return &BlocksCreator{
		blocks:   make(map[int64]*Block),
		commiter: commiter,
	}
}

func (bc *BlocksCreator) Run(ctx context.Context) error {
	var blockID int64
	for {
		blockID = common.GetBlockId(time.Now())
		if oldBlock, ok := bc.blocks[blockID-100]; ok { // Commit and delete old block
			bc.prevBlockHash = oldBlock.CalcHash()
			bc.commiter.CommitBlock(ctx, oldBlock)
			delete(bc.blocks, blockID-100)
		}
		bc.blocks[blockID] = NewBlock(blockID, bc.prevBlockHash)
		time.Sleep(time.Until(time.Unix(blockID+100, 0)))
	}
}

func (bc *BlocksCreator) WriteTx(opts *common.NewTxOpts) error {
	currentBlockID := common.GetBlockId(time.Now())
	if currentBlockID < opts.BlockId {
		return errors.New("block with such id wasn't created yet. " +
			"Ensure that you generate block IDs in UTC timezone")
	} else if currentBlockID > opts.BlockId {
		return errors.New("block id is out of date")
	}
	return werr.Wrapf(bc.blocks[currentBlockID].AddTx(opts),
		"error adding transaction to block %d", currentBlockID)
}