from datetime import datetime, timedelta
from typing import TYPE_CHECKING, Dict, Any

from PyQt6.QtCore import pyqtProperty, pyqtSignal, pyqtSlot
from PyQt6.QtCore import Qt, QAbstractListModel, QModelIndex

from electrum.logging import get_logger
from electrum.util import Satoshis, TxMinedInfo
from electrum.address_synchronizer import TX_HEIGHT_FUTURE, TX_HEIGHT_LOCAL

from electrum.gui.common_qt.util import QtEventListener, qt_event_listener

from .qetypes import QEAmount

if TYPE_CHECKING:
    from electrum.wallet import Abstract_Wallet


class QETransactionListModel(QAbstractListModel, QtEventListener):
    _logger = get_logger(__name__)

    # define listmodel rolemap
    _ROLE_NAMES=('txid', 'fee_sat', 'height', 'confirmations', 'timestamp', 'monotonic_timestamp',
                 'incoming', 'value', 'date', 'label', 'txpos_in_block', 'fee',
                 'inputs', 'outputs', 'section', 'type', 'lightning', 'payment_hash', 'key', 'complete')
    _ROLE_KEYS = range(Qt.ItemDataRole.UserRole, Qt.ItemDataRole.UserRole + len(_ROLE_NAMES))
    _ROLE_MAP  = dict(zip(_ROLE_KEYS, [bytearray(x.encode()) for x in _ROLE_NAMES]))
    _ROLE_RMAP = dict(zip(_ROLE_NAMES, _ROLE_KEYS))

    requestRefresh = pyqtSignal()

    def __init__(self, wallet: 'Abstract_Wallet', parent=None, *, onchain_domain=None, include_lightning=True):
        super().__init__(parent)
        self.wallet = wallet
        self.onchain_domain = onchain_domain
        self.include_lightning = include_lightning

        self.tx_history = []

        self.register_callbacks()
        self.destroyed.connect(lambda: self.on_destroy())
        self.requestRefresh.connect(lambda: self.initModel())

        self._dirty = True
        self.initModel()

    def on_destroy(self):
        self.unregister_callbacks()

    @qt_event_listener
    def on_event_verified(self, wallet, txid, info):
        if wallet == self.wallet:
            self._logger.debug('verified event for txid %s' % txid)
            self.on_tx_verified(txid, info)

    @qt_event_listener
    def on_event_adb_set_future_tx(self, adb, txid):
        if adb != self.wallet.adb:
            return
        self._logger.debug(f'adb_set_future_tx event for txid {txid}')
        for i, item in enumerate(self.tx_history):
            if 'txid' in item and item['txid'] == txid:
                self._update_future_txitem(i)
                return

    @qt_event_listener
    def on_event_fee_histogram(self, histogram):
        self._logger.debug(f'fee histogram updated')
        for i, tx_item in enumerate(self.tx_history):
            if 'height' not in tx_item:  # filter to on-chain
                continue
            if tx_item['confirmations'] > 0:  # filter out already mined
                continue
            txid = tx_item['txid']
            tx = self.wallet.db.get_transaction(txid)
            if not tx:
                continue
            txinfo = self.wallet.get_tx_info(tx)
            status, status_str = self.wallet.get_tx_status(txid, txinfo.tx_mined_status)
            tx_item['date'] = status_str
            index = self.index(i, 0)
            roles = [self._ROLE_RMAP['date']]
            self.dataChanged.emit(index, index, roles)

    @qt_event_listener
    def on_event_labels_received(self, wallet, labels):
        if wallet == self.wallet:
            self.initModel(True)  # TODO: be less dramatic

    def rowCount(self, index):
        return len(self.tx_history)

    # also expose rowCount as a property
    countChanged = pyqtSignal()
    @pyqtProperty(int, notify=countChanged)
    def count(self):
        return len(self.tx_history)

    def roleNames(self):
        return self._ROLE_MAP

    def data(self, index, role):
        tx = self.tx_history[index.row()]
        role_index = role - Qt.ItemDataRole.UserRole

        try:
            value = tx[self._ROLE_NAMES[role_index]]
        except KeyError as e:
            self._logger.error(f'non-existing key "{self._ROLE_NAMES[role_index]}" requested')
            value = None

        if isinstance(value, (bool, list, int, str, QEAmount)) or value is None:
            return value
        if isinstance(value, Satoshis):
            return value.value
        return str(value)

    @pyqtSlot()
    def setDirty(self):
        self._dirty = True

    def clear(self):
        self.beginResetModel()
        self.tx_history = []
        self.endResetModel()

    def tx_to_model(self, tx_item):
        #self._logger.debug(str(tx_item))
        item = tx_item

        item['key'] = item.get('txid') or item['payment_hash'] or item['group_id'] # fixme: this is fragile

        if 'lightning' not in item:
            item['lightning'] = False

        if item['lightning']:
            item['value'] = QEAmount(amount_sat=item['value'].value, amount_msat=item['amount_msat'])
            item['incoming'] = True if item['amount_msat'] > 0 else False
            item['confirmations'] = 0
        else:
            item['value'] = QEAmount(amount_sat=item['value'].value)

        if 'txid' in item:
            tx = self.wallet.db.get_transaction(item['txid'])
            if tx:
                item['complete'] = tx.is_complete()
            else:  # due to races, tx might have already been removed from history
                item['complete'] = False

        # newly arriving txs, or (partially/fully signed) local txs have no (block) timestamp
        # FIXME just use wallet.get_tx_status, and change that as needed
        if not item['timestamp']:  # onchain: local or mempool or unverified txs
            if not item['lightning']:
                txid = item['txid']
                assert txid
                tx_mined_info = self._tx_mined_info_from_tx_item(tx_item)
                item['section'] = 'local' if tx_mined_info.is_local_like() else 'mempool'
                status, status_str = self.wallet.get_tx_status(txid, tx_mined_info=tx_mined_info)
                item['date'] = status_str
        else:  # lightning or already mined (and SPV-ed) onchain txs
            item['section'] = self.get_section_by_timestamp(item['timestamp'])
            item['date'] = self.format_date_by_section(item['section'], datetime.fromtimestamp(item['timestamp']))

        return item

    @staticmethod
    def get_section_by_timestamp(timestamp):
        txts = datetime.fromtimestamp(timestamp)
        today = datetime.today().replace(hour=0, minute=0, second=0, microsecond=0)

        if txts > today:
            return 'today'
        elif txts > today - timedelta(days=1):
            return 'yesterday'
        elif txts > today - timedelta(days=7):
            return 'lastweek'
        elif txts > today - timedelta(days=31):
            return 'lastmonth'
        else:
            return 'older'

    @staticmethod
    def format_date_by_section(section: str, date: datetime):
        # TODO: l10n
        dfmt = {
            'today': '%H:%M',
            'yesterday': '%H:%M',
            'lastweek': '%a, %H:%M',
            'lastmonth': '%a %d, %H:%M',
            'older': '%Y-%m-%d %H:%M'
        }
        if section not in dfmt:
            section = 'older'
        return date.strftime(dfmt[section])

    @staticmethod
    def _tx_mined_info_from_tx_item(tx_item: Dict[str, Any]) -> TxMinedInfo:
        # FIXME a bit hackish to have to reconstruct the TxMinedInfo... same thing in qt-gui
        tx_mined_info = TxMinedInfo(
            _height=tx_item['height'],
            conf=tx_item['confirmations'],
            timestamp=tx_item['timestamp'],
            wanted_height=tx_item.get('wanted_height', None),
        )
        return tx_mined_info

    @pyqtSlot()
    @pyqtSlot(bool)
    def initModel(self, force: bool = False):
        # only (re)construct if dirty or forced
        if not self._dirty and not force:
            return

        self._logger.debug('retrieving history')
        history = self.wallet.get_full_history(
            onchain_domain=self.onchain_domain,
            include_lightning=self.include_lightning,
        )
        txs = []
        for key, tx in history.items():
            txs.append(self.tx_to_model(tx))

        self.clear()
        self.beginInsertRows(QModelIndex(), 0, len(txs) - 1)
        self.tx_history = txs
        self.tx_history.reverse()
        self.endInsertRows()

        self.countChanged.emit()

        self._dirty = False

    def on_tx_verified(self, txid: str, info: TxMinedInfo):
        for i, tx in enumerate(self.tx_history):
            if 'txid' in tx and tx['txid'] == txid:
                tx['height'] = info.height()
                tx['confirmations'] = info.conf
                tx['timestamp'] = info.timestamp
                tx['section'] = self.get_section_by_timestamp(info.timestamp)
                tx['date'] = self.format_date_by_section(tx['section'], datetime.fromtimestamp(info.timestamp))
                index = self.index(i, 0)
                roles = [self._ROLE_RMAP[x] for x in ['section', 'height', 'confirmations', 'timestamp', 'date']]
                self.dataChanged.emit(index, index, roles)
                return

    def _update_future_txitem(self, tx_item_idx: int):
        tx_item = self.tx_history[tx_item_idx]
        # note: local txs can transition to future, as "future" state is not persisted
        if tx_item.get('height') not in (TX_HEIGHT_FUTURE, TX_HEIGHT_LOCAL):
            return
        txid = tx_item['txid']
        tx = self.wallet.db.get_transaction(txid)
        if tx is None:
            return
        txinfo = self.wallet.get_tx_info(tx)
        status, status_str = self.wallet.get_tx_status(txid, txinfo.tx_mined_status)
        tx_item['date'] = status_str
        # note: if the height changes, that might affect the history order, but we won't re-sort now.
        tx_item['height'] = self.wallet.adb.get_tx_height(txid).height()
        index = self.index(tx_item_idx, 0)
        roles = [self._ROLE_RMAP[x] for x in ['height', 'date']]
        self.dataChanged.emit(index, index, roles)

    @pyqtSlot(str, str)
    def updateTxLabel(self, key, label):
        for i, tx in enumerate(self.tx_history):
            if tx['key'] == key:
                tx['label'] = label
                index = self.index(i, 0)
                self.dataChanged.emit(index, index, [self._ROLE_RMAP['label']])
                return

    @pyqtSlot(int)
    def updateBlockchainHeight(self, height):
        self._logger.debug('updating height to %d' % height)
        for i, tx_item in enumerate(self.tx_history):
            if 'height' in tx_item:
                if tx_item['height'] > 0:
                    tx_item['confirmations'] = height - tx_item['height'] + 1
                    index = self.index(i, 0)
                    roles = [self._ROLE_RMAP['confirmations']]
                    self.dataChanged.emit(index, index, roles)
                elif tx_item['height'] in (TX_HEIGHT_FUTURE, TX_HEIGHT_LOCAL):
                    self._update_future_txitem(i)
