# standard imports
import os
import json
import logging

# external imports
from hexathon import strip_0x
from chainlib.eth.tx import (
        Tx,
        pack,
        )
from leveldir.numeric import NumDir
from leveldir.hex import HexDir

logg = logging.getLogger(__name__)

default_base_dir = '/var/lib'


def chain_dir_for(chain_spec, base_dir=default_base_dir):
    chain_dir = os.path.join(base_dir, str(chain_spec).replace(':', '/'))
    return os.path.join(chain_dir, 'eth_cache')


class FileStore:

    def put_tx(self, tx, include_data=False):
        raw = pack(tx.src, self.chain_spec)
        tx_hash_dirnormal = strip_0x(tx.hash).upper()
        tx_hash_bytes = bytes.fromhex(tx_hash_dirnormal)
        self.tx_raw_dir.add(tx_hash_bytes, raw)
        addresses = []
        if self.address_rules != None:
            for a in tx.outputs + tx.inputs:
                if a not in addresses:
                    addresses.append(a)
        else:
            for a in tx.outputs + tx.inputs:
                addresses.append(a)

        for a in addresses:
            a_hex = strip_0x(a).upper()
            a = bytes.fromhex(a_hex)
            self.address_dir.add_dir(tx_hash_dirnormal, a, b'')
            dirpath = self.address_dir.to_filepath(a_hex)
            fp = os.path.join(dirpath, '.start')
            num = tx.block.number
            num_compare = 0
            try:
                f = open(fp, 'rb')
                r = f.read(8)
                f.close()
                num_compare = int.from_bytes(r, 'big')
            except FileNotFoundError:
                pass

            if num_compare == 0 or num < num_compare:
                logg.debug('recoding new start block {} for {}'.format(num, a))
                num_bytes = num.to_bytes(8, 'big')
                f = open(fp, 'wb')
                f.write(num_bytes)
                f.close()

        if include_data:
            src = json.dumps(tx.src).encode('utf-8')
            self.tx_dir.add(bytes.fromhex(strip_0x(tx.hash)), src)

            rcpt_src = tx.result.src
            logg.debug('rcpt {}'.format(rcpt_src))
            if rcpt_src != None:
                rcpt_src = json.dumps(rcpt_src).encode('utf-8')
                self.rcpt_dir.add(bytes.fromhex(strip_0x(tx.hash)), rcpt_src)



    def put_block(self, block, include_data=False):
        hash_bytes = bytes.fromhex(strip_0x(block.hash))
        self.block_num_dir.add(block.number, hash_bytes)
        num_bytes = block.number.to_bytes(8, 'big')
        self.block_hash_dir.add(hash_bytes, num_bytes)
        if include_data:
            src = json.dumps(block.src).encode('utf-8')
            self.block_src_dir.add(hash_bytes, src)


    def get_block_number(self, block_number):
        fp = self.block_num_dir.to_filepath(block_number)
        f = open(fp, 'rb')
        r = f.read()
        f.close()
        return self.get_block(r.hex())


    def get_block(self, block_hash):
        fp = self.block_src_dir.to_filepath(block_hash)
        f = open(fp, 'rb')
        r = f.read()
        f.close()
        return r


    def get_tx(self, tx_hash):
        fp = self.tx_dir.to_filepath(tx_hash)
        f = open(fp, 'rb')
        r = f.read()
        f.close()
        return r


    def get_rcpt(self, tx_hash):
        fp = self.rcpt_dir.to_filepath(tx_hash)
        f = open(fp, 'rb')
        r = f.read()
        f.close()
        return r


    def get_address_tx(self, address):
        fp = self.address_dir.to_filepath(address)
        tx_hashes = []
        for tx_hash in os.listdir(fp):
            if tx_hash[0] == '.':
                continue
            tx_hashes.append(tx_hash)
        return tx_hashes


    def __init__(self, chain_spec, cache_root=default_base_dir, address_rules=None):
        self.chain_dir = chain_dir_for(chain_spec, cache_root)
        self.cache_dir = self.chain_dir
        self.block_src_path = os.path.join(self.cache_dir, 'block', 'src')
        self.block_src_dir = HexDir(self.block_src_path, 32, levels=2)
        self.block_num_path = os.path.join(self.cache_dir, 'block', 'num')
        self.block_num_dir = NumDir(self.block_num_path, [100000, 1000])
        self.block_hash_path = os.path.join(self.cache_dir, 'block', 'hash')
        self.block_hash_dir = HexDir(self.block_hash_path, 32, levels=2)
        self.tx_path = os.path.join(self.cache_dir, 'tx', 'src')
        self.tx_raw_path = os.path.join(self.cache_dir, 'tx', 'raw')
        self.tx_dir = HexDir(self.tx_path, 32, levels=2)
        self.tx_raw_dir = HexDir(self.tx_raw_path, 32, levels=2)
        self.rcpt_path = os.path.join(self.cache_dir, 'rcpt', 'src')
        self.rcpt_raw_path = os.path.join(self.cache_dir, 'rcpt', 'raw')
        self.rcpt_dir = HexDir(self.rcpt_path, 32, levels=2)
        self.rcpt_raw_dir = HexDir(self.rcpt_raw_path, 32, levels=2)
        self.address_path = os.path.join(self.cache_dir, 'address')
        self.address_dir = HexDir(self.address_path, 20, levels=2)
        self.chain_spec = chain_spec
        self.address_rules = address_rules


    def __str__(self):
        return 'FileStore: root {}'.format(self.cache_dir)