from flask import Blueprint, render_template, redirect, url_for, flash, request, jsonify
from flask_login import login_required
from flask_wtf import FlaskForm
from wtforms import StringField, SelectField, DecimalField, DateField, TextAreaField, SubmitField
from wtforms.validators import DataRequired, Optional, NumberRange, Length
from app.extensions import db
from app.models.investment import Investment, InvestmentTransaction
from app.services.investment_service import (
    get_portfolio_summary, update_prices, fetch_price,
    fetch_price_history, fetch_day_change,
    get_price_alerts,
    ASSET_COLORS, ASSET_TYPE_LABELS
)
from datetime import date
from decimal import Decimal

investments_bp = Blueprint('investments', __name__, url_prefix='/investments')

ASSET_TYPES = [
    ('stock',       'Stock'),
    ('etf',         'ETF'),
    ('crypto',      'Crypto'),
    ('real_estate', 'Real Estate'),
    ('bond',        'Bond'),
    ('cash',        'Cash'),
    ('other',       'Other'),
]

TXN_TYPES = [
    ('buy',      'Buy'),
    ('sell',     'Sell'),
    ('dividend', 'Dividend'),
    ('split',    'Split'),
]


class InvestmentForm(FlaskForm):
    asset_name = StringField('Asset Name', validators=[DataRequired(), Length(1, 100)])
    ticker = StringField('Ticker Symbol', validators=[Optional(), Length(max=20)],
                         description='e.g. AAPL, BTC-USD, VNM')
    asset_type = SelectField('Asset Type', choices=ASSET_TYPES, validators=[DataRequired()])
    shares = DecimalField('Shares / Units', validators=[Optional(), NumberRange(min=0)],
                          places=8, default=Decimal('0'))
    avg_cost_basis = DecimalField('Avg Cost per Share', validators=[Optional(), NumberRange(min=0)],
                                  places=4, default=Decimal('0'))
    notes = TextAreaField('Notes', validators=[Optional()])
    submit = SubmitField('Save')


class InvestmentTransactionForm(FlaskForm):
    transaction_type = SelectField('Type', choices=TXN_TYPES, validators=[DataRequired()])
    shares = DecimalField('Shares / Units', validators=[DataRequired(), NumberRange(min=0.000001)],
                          places=8)
    price_per_share = DecimalField('Price per Share', validators=[DataRequired(), NumberRange(min=0)],
                                   places=4)
    fees = DecimalField('Fees', validators=[Optional()], places=2, default=0)
    date = DateField('Date', validators=[DataRequired()], default=date.today)
    notes = StringField('Notes', validators=[Optional(), Length(max=255)])
    submit = SubmitField('Record Transaction')


def _recalc_holding(investment):
    """
    Recalculate shares and avg_cost_basis from transaction log (FIFO approach).
    """
    txns = investment.inv_transactions.order_by(
        InvestmentTransaction.date.asc()
    ).all()

    total_shares = Decimal('0')
    total_cost = Decimal('0')

    for txn in txns:
        shares = Decimal(str(txn.shares))
        price = Decimal(str(txn.price_per_share))
        fees = Decimal(str(txn.fees or 0))

        if txn.transaction_type == 'buy':
            total_cost += (shares * price) + fees
            total_shares += shares
        elif txn.transaction_type == 'sell':
            if total_shares > 0:
                avg = total_cost / total_shares
                total_cost -= avg * min(shares, total_shares)
            total_shares = max(total_shares - shares, Decimal('0'))
        elif txn.transaction_type == 'dividend':
            pass  # dividends don't change cost basis
        elif txn.transaction_type == 'split':
            # treat split ratio as shares multiplier
            total_shares += shares

    investment.shares = total_shares
    investment.avg_cost_basis = (total_cost / total_shares) if total_shares > 0 else Decimal('0')
    db.session.commit()


@investments_bp.route('/sync-schwab', methods=['POST'])
@login_required
def sync_schwab():
    """Sync balance + positions for every mapped Schwab account, then return here."""
    from app.models.schwab_connection import SchwabConnection, SchwabAccount
    from app.services.schwab_service import sync_account_snapshot
    import logging
    log = logging.getLogger(__name__)

    # Use the active connection for ALL mapped accounts regardless of which
    # connection_id was stored — accounts may still reference an old connection
    # after a reconnect if the callback didn't update every record.
    connection = SchwabConnection.query.filter_by(is_active=True).first()
    if not connection:
        flash('No active Schwab connection. Connect at the Schwab page first.', 'warning')
        return redirect(url_for('investments.index'))

    accounts = SchwabAccount.query.filter(
        SchwabAccount.pfm_account_id != None,
        SchwabAccount.is_active == True,
    ).all()

    if not accounts:
        flash('No Schwab accounts mapped yet. Map them on the Schwab page first.', 'warning')
        return redirect(url_for('investments.index'))

    # Patch every account to use the active connection before syncing
    for sa in accounts:
        sa.connection = connection

    ok_accounts, fail_accounts = [], []
    total_pos = 0
    for sa in accounts:
        try:
            _, pos = sync_account_snapshot(sa)
            total_pos += pos
            ok_accounts.append(sa.account_name)
        except Exception as e:
            log.error('[schwab] sync_schwab failed for %s: %s', sa.account_name, e, exc_info=True)
            fail_accounts.append(f'{sa.account_name} ({e})')

    if ok_accounts:
        flash(f'Synced {len(ok_accounts)} account(s)'
              f'{f", {total_pos} position(s)" if total_pos else ""}.'
              f' ({", ".join(ok_accounts)})', 'success')
    if fail_accounts:
        flash(f'Failed: {"; ".join(fail_accounts)}', 'danger')
    if not ok_accounts and not fail_accounts:
        flash('No mapped Schwab accounts found.', 'info')
    return redirect(url_for('investments.index'))


@investments_bp.route('/')
@login_required
def index():
    portfolio = get_portfolio_summary()

    # Build allocation chart data
    chart_labels = [ASSET_TYPE_LABELS.get(a['type'], a['type']) for a in portfolio['allocation']]
    chart_values = [round(a['value'], 2) for a in portfolio['allocation']]
    chart_colors = [a['color'] for a in portfolio['allocation']]

    return render_template('investments/index.html',
                           portfolio=portfolio,
                           chart_labels=chart_labels,
                           chart_values=chart_values,
                           chart_colors=chart_colors,
                           asset_colors=ASSET_COLORS,
                           asset_labels=ASSET_TYPE_LABELS)


@investments_bp.route('/new', methods=['GET', 'POST'])
@login_required
def new():
    form = InvestmentForm()
    if form.validate_on_submit():
        inv = Investment(
            asset_name=form.asset_name.data.strip(),
            ticker=form.ticker.data.strip().upper() if form.ticker.data else None,
            asset_type=form.asset_type.data,
            shares=0,
            avg_cost_basis=0,
            notes=form.notes.data,
        )
        db.session.add(inv)
        db.session.commit()
        # Fetch initial price if ticker provided
        if inv.ticker:
            price = fetch_price(inv.ticker)
            if price:
                inv.current_price = price
                from datetime import datetime
                inv.last_price_update = datetime.utcnow()
                db.session.commit()
        flash(f'"{inv.asset_name}" added. Record your first buy transaction.', 'success')
        return redirect(url_for('investments.detail', id=inv.id))
    return render_template('investments/form.html', form=form, title='Add Investment')


@investments_bp.route('/<int:id>')
@login_required
def detail(id):
    inv = db.get_or_404(Investment, id)
    txns = inv.inv_transactions.order_by(
        InvestmentTransaction.date.desc()
    ).all()
    return render_template('investments/detail.html', inv=inv, txns=txns,
                           asset_labels=ASSET_TYPE_LABELS,
                           asset_colors=ASSET_COLORS)


@investments_bp.route('/<int:id>/edit', methods=['GET', 'POST'])
@login_required
def edit(id):
    inv = db.get_or_404(Investment, id)
    form = InvestmentForm(obj=inv)
    if form.validate_on_submit():
        inv.asset_name = form.asset_name.data.strip()
        inv.ticker = form.ticker.data.strip().upper() if form.ticker.data else None
        inv.asset_type = form.asset_type.data
        inv.notes = form.notes.data
        # Manual override of shares/cost basis — only update if user provided values
        if form.shares.data is not None:
            inv.shares = form.shares.data
        if form.avg_cost_basis.data is not None:
            inv.avg_cost_basis = form.avg_cost_basis.data
        db.session.commit()
        flash('Investment updated.', 'success')
        return redirect(url_for('investments.detail', id=inv.id))
    # Pre-populate shares/cost for edit form
    if request.method == 'GET':
        form.shares.data = inv.shares
        form.avg_cost_basis.data = inv.avg_cost_basis
    return render_template('investments/form.html', form=form, title='Edit Investment', inv=inv)


@investments_bp.route('/<int:id>/delete', methods=['POST'])
@login_required
def delete(id):
    inv = db.get_or_404(Investment, id)
    inv.is_active = False
    db.session.commit()
    flash(f'"{inv.asset_name}" removed.', 'info')
    return redirect(url_for('investments.index'))


@investments_bp.route('/<int:id>/transactions/new', methods=['GET', 'POST'])
@login_required
def add_transaction(id):
    inv = db.get_or_404(Investment, id)
    form = InvestmentTransactionForm()

    if form.validate_on_submit():
        shares = form.shares.data
        price = form.price_per_share.data
        fees = form.fees.data or 0
        total = float(shares) * float(price)

        txn = InvestmentTransaction(
            investment_id=inv.id,
            transaction_type=form.transaction_type.data,
            shares=shares,
            price_per_share=price,
            total_amount=total,
            fees=fees,
            date=form.date.data,
            notes=form.notes.data,
        )
        db.session.add(txn)
        db.session.commit()

        # Recalculate holding from transaction log
        _recalc_holding(inv)

        # Update current price if no price yet
        if inv.current_price is None and inv.ticker:
            p = fetch_price(inv.ticker)
            if p:
                from datetime import datetime
                inv.current_price = p
                inv.last_price_update = datetime.utcnow()
                db.session.commit()

        flash(f'{form.transaction_type.data.title()} transaction recorded.', 'success')
        return redirect(url_for('investments.detail', id=inv.id))

    return render_template('investments/transaction_form.html',
                           form=form, inv=inv,
                           title=f'New Transaction — {inv.asset_name}')


@investments_bp.route('/transactions/<int:id>/delete', methods=['POST'])
@login_required
def delete_transaction(id):
    txn = db.get_or_404(InvestmentTransaction, id)
    inv = txn.investment
    db.session.delete(txn)
    db.session.commit()
    _recalc_holding(inv)
    flash('Transaction deleted.', 'info')
    return redirect(url_for('investments.detail', id=inv.id))


@investments_bp.route('/refresh-prices', methods=['POST'])
@login_required
def refresh_prices():
    updated = update_prices()
    if updated:
        flash(f'Updated prices for: {", ".join(updated.keys())}', 'success')
    else:
        flash('No prices updated (no tickers or fetch failed).', 'warning')
    return redirect(url_for('investments.index'))


@investments_bp.route('/api/price/<ticker>')
@login_required
def api_price(ticker):
    """Live price lookup for a ticker — used in the add/edit investment form."""
    ticker = ticker.upper().strip()
    error = None
    price = None
    try:
        price = fetch_price(ticker)
        if price is None:
            error = f'No data returned for {ticker}. Check the ticker format.'
    except Exception as e:
        error = str(e)

    return jsonify({
        'ticker': ticker,
        'price':  price,
        'error':  error,
    })


@investments_bp.route('/api/daychange/<ticker>')
@login_required
def api_day_change(ticker):
    """
    Lightweight endpoint: return today's open-to-current day change only.
    Used by the portfolio page to load change badges quickly.
    """
    data = fetch_day_change(ticker.upper().strip())
    if data is None:
        return jsonify({'error': f'No data for {ticker}'}), 404
    return jsonify(data)


@investments_bp.route('/api/price-alerts')
@login_required
def api_price_alerts():
    """Return today's price-alert list (holdings that moved >= 5% intraday)."""
    return jsonify({'alerts': get_price_alerts()})


@investments_bp.route('/api/history/<ticker>')
@login_required
def api_price_history(ticker):
    """
    Return OHLC history + day/period change for a ticker.
    Query param: tf = 1W | 1M | 3M | 6M | 1Y  (default 1M)
    Used by the portfolio page inline charts.
    """
    tf = request.args.get('tf', '1M').upper()
    if tf not in ('1W', '1M', '3M', '6M', '1Y'):
        tf = '1M'

    data = fetch_price_history(ticker.upper().strip(), tf)
    if data is None:
        return jsonify({'error': f'No history data available for {ticker}'}), 404

    return jsonify(data)