#!/usr/bin/env python3

import re
import subprocess
import sys

if len(sys.argv) == 2:
    year = sys.argv[1]
else:
    year = '2023'

def ledger_amount(query):
    p = subprocess.run("ledger -p '%s' -n -J --yearly reg %s" % (year, query,),
            shell=True, stdout=subprocess.PIPE, text=True)
    parts = p.stdout.split(' ')
    if len(parts) == 2:
        return float(parts[1])
    else:
        return 0.0

def parse_tax_table(input):
    filing_status = 2 # Married/Jointly
    table = []
    delta = 0
    prev_max_tax = 0
    for line in input.split("\n"):
        if not line:
            continue
        cols = line.split("\t")
        rate = float(cols[0].strip(' %')) / 100.0
        brk = re.sub('[$,]', '', cols[filing_status]).split(' ')
        lower = brk[0]
        upper = brk[2]
        delta
        if upper == 'more':
            table.append((float(lower), None, rate, delta))
        else:
            delta += rate * float(lower) - prev_max_tax
            prev_max_tax = float(upper) * rate
            table.append((float(lower), float(upper), rate, delta))
    return table

    
income_tax_table = {}

# c&p from https://taxfoundation.org/2022-tax-brackets/
income_tax_table['2022'] = parse_tax_table('''
10% 	$0 to $10,275 	$0 to $20,550 	$0 to $14,650
12% 	$10,275 to $41,775 	$20,550 to $83,550 	$14,650 to $55,900
22% 	$41,775 to $89,075 	$83,550 to $178,150 	$55,900 to $89,050
24% 	$89,075 to $170,050 	$178,150 to $340,100 	$89,050 to $170,050
32% 	$170,050 to $215,950 	$340,100 to $431,900 	$170,050 to $215,950
35% 	$215,950 to $539,900 	$431,900 to $647,850 	$215,950 to $539,900
37% 	$539,900 or more 	$647,850 or more 	$539,900 or more
''')

# c&p from https://taxfoundation.org/2023-tax-brackets/
income_tax_table['2023'] = parse_tax_table('''
10% 	$0 to $11,000 	$0 to $22,000 	$0 to $15,700
12% 	$11,000 to $44,725 	$22,000 to $89,450 	$15,700 to $59,850
22% 	$44,725 to $95,375 	$89,450 to $190,750 	$59,850 to $95,350
24% 	$95,375 to $182,100 	$190,750 to $364,200 	$95,350 to $182,100
32% 	$182,100 to $231,250 	$364,200 to $462,500 	$182,100 to $231,250
35% 	$231,250 to $578,125 	$462,500 to $693,750 	$231,250 to $578,100
37% 	$578,125 or more 	$693,750 or more 	$578,100 or more
''')

def compute_income_tax(income):
    for (lower, upper, rate, sub) in income_tax_table[year]:
        if income > lower and (upper is None or income <= upper):
            return round(income * rate - sub)
    raise Exception("Failed to compute tax")

def compute_tax_worksheet(taxable_income, qualified_dividends, schedule_d):
    line       = {}
    line['1']  = taxable_income
    line['2']  = qualified_dividends
    line['3']  = max(0, min(schedule_d['15'], schedule_d['16']))
    line['4']  = line['2'] + line['3']
    line['5']  = max(0, taxable_income - line['4'])
    line['6']  = 83350.00 # TODO Tax table (this number from 2022)
    line['7']  = min(taxable_income, line['6'])
    line['8']  = min(line['5'], line['7'])
    line['9']  = line['7'] - line['8'] # 0% tax amount
    line['10'] = min(taxable_income, line['4'])
    line['11'] = line['9']
    line['12'] = line['10'] - line['11']
    line['13'] = 517200.00 # TODO Tax table (this number from 2022)
    line['14'] = min(taxable_income, line['13'])
    line['15'] = line['5'] + line['9']
    line['16'] = max(0, line['14'] - line['15'])
    line['17'] = min(line['12'], line['16'])
    line['18'] = line['17'] * 0.15
    line['19'] = line['9'] + line['17']
    line['20'] = line['10'] - line['19']
    line['21'] = line['20'] * 0.20
    line['22'] = compute_income_tax(line['5'])
    line['23'] = line['18'] + line['21'] + line['22']
    line['24'] = compute_income_tax(taxable_income)
    line['25'] = min(line['23'], line['24'])
    return line

def compute_schedule_d(net_st, net_lt):
    line       = {}
    line['7']  = net_st
    line['15'] = net_lt
    line['16'] = line['7'] + line['15']

    # N.B. this deviates from the instructions 
    # For simplicity, Form 1040 will always get line 7 from schedule D line 21.
    line['21'] = line['16']

    if line['16'] > 0:
        if line['15'] > 0:
            line['17'] = 'Yes'
            line['18'] = 0.00 # TODO: 28% Rate Gain Worksheet
            line['19'] = 0.00 # TODO: Section 1250 Worksheet
            if line['18'] == 0.00 and line['19'] == 0.00:
                line['20'] = 'Yes'
                return line
            else:
                line['20'] = 'No'
                raise Exception("TODO: Implement Schedule D worksheet")
        else:
            line['17'] = 'No'
            # Goto line 22
    elif line['16'] < 0:
        # Goto Line 21 (and 22)
        line['21'] = max(-3000.00, line['16'])

    # Line 22 - Do you have qualified dividends?

    return line

def compute_deduction(deductions, limited):
    itemized  = deductions 
    itemized += min(10000, limited)
    standard = 25900  # TODO Tax table
    return max(itemized, standard)

def credit_limit_worksheet_a(line18):
    line       = {}
    line['1']  = line18
    line['2']  = 0.00                   # TODO: Schedule 3
    line['3']  = line['1'] - line['2']
    line['4']  = 0                      # TODO: Credit Limit Worksheet B
    line['5']  = line['3'] - line['4']
    return line

# Schedule 8812
def compute_child_tax_credit(agi, dependants, line18):
    line       = {}
    line['1']  = agi
    line['3']  = line['1']
    line['4']  = dependants
    line['5']  = line['4'] * 2000.00
    line['6']  = 0
    line['7']  = line['6'] * 500.00
    line['8']  = line['5'] + line['7']
    line['9']  = 400000.00 # Married, filing jointly
    line['10'] = max(0, round((line['3'] - line['9'])/1000) * 1000)
    line['11'] = line['10'] * 0.05
    if line['8'] > line['11']:
        line['12'] = line['8'] - line['11']
    else:
        line['14'] = 0
        line['27'] = 0
        return line
    line['13'] = credit_limit_worksheet_a(line18)['5']
    line['14'] = min(line['12'], line['13'])
    return line


    

print("Tax report for %s" % (year))
print("-------------------")

#################################
# Gather ledger values

# Income
income              = 0 - ledger_amount('tag EarnedIncome')
taxable_interest    = 0 - ledger_amount('"Interest and not HSA"')
qualified_dividends = 0 - ledger_amount('tag QualifiedDividends')
ordinary_dividends  = 0 - ledger_amount('tag OrdinaryDividends')
net_st              = 0 - ledger_amount('tag ShortTermGains')
net_lt              = 0 - ledger_amount('tag LongTermGains')

# Expenses
total_payments      = ledger_amount('tag TaxesPaid')
deductions          = ledger_amount('tag ^TaxDeductible$')
deductions_limited  = ledger_amount('tag ^TaxDeductibleLimited$')

# Other
dependants          = 2


############################
# Compute taxes


schedule_d = compute_schedule_d(net_st, net_lt)

line       = {}

# Income
line['1z'] = income
line['2b'] = taxable_interest
line['3a'] = qualified_dividends
line['3b'] = ordinary_dividends
line['4b'] = 0.00                # TODO: IRA Distribution
line['5b'] = 0.00                # TODO: Pension
line['6b'] = 0.00                # TODO: Social security
line['7']  = schedule_d['21']
line['8']  = 0.00 # TODO: Schedule 1
line['9']  = line['1z'] + line['2b'] + line['3b'] + line['4b'] + \
             line['5b'] + line['6b'] + line['7'] + line['8']

line['10'] = 0.00                # TODO Schedule 1 (line 26)
line['11'] = line['9'] - line['10']

line['12'] = compute_deduction(deductions, deductions_limited)
line['13'] = 0.00                # TODO: Form 8995
line['14'] = line['12'] + line['13']
line['15'] = max(0, line['11'] - line['14'])

# Tax and Credits
tax_worksheet = compute_tax_worksheet(line['15'], line['3a'], schedule_d)
line['16'] = tax_worksheet['25']
line['17'] = 0.00                # TODO: Schedule 2 (line 3)
line['18'] = line['16'] + line['17']
line['19'] = compute_child_tax_credit(line['11'], dependants, line['18'])['14']
line['20'] = 0.00                # TODO: Schedule 3 (line 8)
line['21'] = line['19'] + line['20']
line['22'] = max(0, line['18'] - line['21'])
line['23'] = 0.00                # TODO Schedule 2 (line 21)
line['24'] = line['22'] + line['23']

# Payments
line['33'] = total_payments

# Refund
line['34'] = max(0, line['33'] - line['24'])

# Amount You Owe
line['37'] = max(0, line['24'] - line['33'])
# TODO Penalty


####################

print(" 1z. Total income         ${:>12,.0f}".format(line['1z']))
print(" 2b. Taxable interest     ${:>12,.0f}".format(line['2b']))
print(" 3b. Ordinary dividends   ${:>12,.0f}".format(line['3b']))
print("  7. Capital gain (loss)  ${:>12,.0f}".format(line['7']))
print("  8. Other income         ${:>12,.0f}".format(line['8']))
print("  9. Total income         ${:>12,.0f}".format(line['9']))
print(" 10. Adjustments          ${:>12,.0f}".format(line['10']))
print(" 11. AGI                  ${:>12,.0f}".format(line['11']))
print() 

print(" 12. Deductions           ${:>12,.0f}".format(line['12']))
print(" 13. Business deduction   ${:>12,.0f}".format(line['13']))
print(" 15. Taxable income       ${:>12,.0f}".format(line['15']))
print()

print(" 16. Tax                  ${:>12,.0f}".format(line['16']))
print(" 16. Total tax            ${:>12,.0f}".format(line['24']))
print(" 33. Total payments       ${:>12,.0f}".format(line['33']))

if line['34'] > 0:
    print(" 34. Tax refund           ${:>12,.0f}".format(line['34']))
else:
    print(" 37. Taxes owed           ${:>12,.0f}".format(line['37']))