# report.py

import fileparse
from stock import Stock
from portfolio import Portfolio
import tableformat

def read_portfolio(filename, **opts):
    '''
    Read a stock portfolio file into a list of dictionaries with keys
    name, shares, and price.
    '''
    with open(filename) as lines:
        return Portfolio.from_csv(lines, **opts)

def read_prices(filename, **opts):
    '''
    Read a CSV file of price data into a dict mapping names to prices.
    '''
    with open(filename) as lines:
        return dict(fileparse.parse_csv(lines, types=[str,float], has_headers=False, **opts))

def make_report(portfolio, prices):
    '''
    Make a list of (name, shares, price, change) tuples given a portfolio list
    and prices dictionary.
    '''
    rows = []
    for s in portfolio:
        current_price = prices[s.name]
        change = current_price - s.price
        summary = (s.name, s.shares, current_price, change)
        rows.append(summary)
    return rows

def print_report(reportdata, formatter):
    '''
    Print a nicely formated table from a list of (name, shares, price, change) tuples.
    '''
    formatter.headings(['Name','Shares','Price','Change'])
    for name, shares, price, change in reportdata:
        rowdata = [ name, str(shares), f'{price:0.2f}', f'{change:0.2f}' ]
        formatter.row(rowdata)

def portfolio_report(portfoliofile, pricefile, fmt='txt'):
    '''
    Make a stock report given portfolio and price data files.
    '''
    # Read data files 
    portfolio = read_portfolio(portfoliofile)
    prices = read_prices(pricefile)

    # Create the report data
    report = make_report(portfolio, prices)

    # Print it out
    formatter = tableformat.create_formatter(fmt)
    print_report(report, formatter)

def main(args):
    if len(args) != 4:
        raise SystemExit('Usage: %s portfile pricefile format' % args[0])
    portfolio_report(args[1], args[2], args[3])

if __name__ == '__main__':
    import sys
    main(sys.argv)