"""R01 原创构造底稿：独立 Decimal 按月模型，不导入网站计算代码。"""
from decimal import Decimal as D, ROUND_HALF_UP, getcontext
from pathlib import Path
import argparse
import json
import re

getcontext().prec = 48
CENT = D('0.01')
ZERO = D(0)
HERE = Path(__file__).resolve().parent

def money(v):
    return D(str(v)).quantize(CENT, rounding=ROUND_HALF_UP)

def installment(balance, rate, months):
    if rate == 0:
        return balance / months
    a = (1 + rate) ** months
    return balance * rate * a / (a - 1)

def count_months(balance, rate, payment, method, remaining):
    """逐月模拟且不超当前到期月，末期清余本，防整分尾差把期限延长。"""
    for n in range(1, remaining+1):
        interest = money(balance * rate)
        principal = min(balance, money(payment) if method == 'principal' else money(payment)-interest)
        if n == remaining:
            principal = balance
        if principal <= 0:
            raise ValueError('正常付款不能摊还本金')
        balance -= principal
        if balance == 0:
            return n
    raise ValueError('超过600期')

def simulate(principal, annual_pct, months, method='annuity', events=None, rates=None, early_order=False):
    """期初调率、计息/正常付款、额外还本；early_order仅供文内独立对照。"""
    assert method in ('annuity', 'principal') and 1 <= months <= 600
    events = events or []
    assert len(events) <= 24
    rate_map = {e['month']: D(str(e['annual_pct']))/1200 for e in (rates or [])}
    event_map = {}
    for e in events:
        m = e['month']
        if m in event_map:
            assert event_map[m]['mode'] == e['mode'], '同月选择冲突'
            event_map[m]['amount'] += money(e['amount'])
            event_map[m]['fee'] += money(e.get('fee', 0))
        else:
            event_map[m] = {'mode': e['mode'], 'amount': money(e['amount']), 'fee': money(e.get('fee', 0))}
    balance = money(principal)
    initial = balance
    rate = D(str(annual_pct))/1200
    end = months
    payment = installment(balance, rate, months) if method == 'annuity' else balance/months
    rows = []
    for m in range(1, 601):
        if balance == 0:
            break
        opening = balance
        old_end = end
        event = event_map.get(m)
        requested = event['amount'] if event else ZERO
        extra = ZERO
        # DJ2-002的B约定：当月额外本金在整月计息前生效。
        if early_order and event:
            extra = min(balance, requested)
            balance -= extra
        if m in rate_map:
            rate = rate_map[m]
            if method == 'annuity':
                payment = installment(balance, rate, end-m+1)
        elif early_order and event and method == 'annuity':
            payment = installment(balance, rate, end-m+1)
        interest_base = balance
        interest = money(balance*rate)
        if method == 'annuity':
            normal_principal = min(balance, money(payment)-interest)
        else:
            normal_principal = min(balance, money(payment))
        if m == end:
            normal_principal = balance
        assert normal_principal > 0 or balance == 0
        normal = normal_principal+interest
        balance -= normal_principal
        after_normal = balance
        if event and not early_order:
            extra = min(balance, requested)
            balance -= extra
        fee = event['fee'] if event else ZERO
        if event and extra > 0 and balance > 0:
            if event['mode'] == 'reduce':
                payment = installment(balance, rate, end-m) if method == 'annuity' else balance/(end-m)
            else:
                end = m+count_months(balance, rate, payment, method, end-m)
        rows.append({'month': m, 'opening': opening, 'annual_pct': rate*1200,
                     'interest_base': interest_base,
                     'interest': interest, 'normal': normal, 'normal_principal': normal_principal,
                     'after_normal': after_normal, 'requested_extra': requested, 'extra': extra,
                     'unused_extra': requested-extra, 'fee': fee, 'cash': normal+extra+fee,
                     'closing': balance, 'previous_end': old_end, 'planned_end': m if balance == 0 else end,
                     'next_payment_or_q': money(payment), 'mode': event['mode'] if event else None})
        assert opening-normal_principal-extra == balance
    assert balance == 0
    skipped = [{'month': m, 'requested_extra': e['amount'], 'extra': ZERO, 'unused_extra': e['amount'],
                'fee': ZERO} for m, e in event_map.items() if m > len(rows)]
    total_principal = sum((r['normal_principal']+r['extra'] for r in rows), ZERO)
    total_interest = sum((r['interest'] for r in rows), ZERO)
    total_fees = sum((r['fee'] for r in rows), ZERO)
    total_cash = sum((r['cash'] for r in rows), ZERO)
    assert total_principal == initial and total_cash == initial+total_interest+total_fees
    return {'rows': rows, 'skipped_events': skipped, 'payoff_month': len(rows),
            'total_normal_principal': sum((r['normal_principal'] for r in rows), ZERO),
            'total_extra': sum((r['extra'] for r in rows), ZERO), 'total_principal': total_principal,
            'total_interest': total_interest, 'total_fees': total_fees, 'total_cash': total_cash,
            'unused_extra': sum((r['unused_extra'] for r in rows), ZERO)+sum((r['unused_extra'] for r in skipped), ZERO)}

def ev(m, amount, mode='shorten', fee=0):
    return {'month': m, 'amount': amount, 'mode': mode, 'fee': fee}

def row(plan, month):
    return plan['rows'][month-1] if month <= len(plan['rows']) else {'interest': ZERO, 'closing': ZERO, 'cash': ZERO}

def build():
    out = {}
    i = {'principal': 120000, 'annual_pct': '3.6', 'months': 24,
         'events': [ev(3,15000,'reduce'), ev(8,12000), ev(12,8000,'reduce')]}
    p = simulate(**i); base = simulate(120000,'3.6',24)
    out['DJ2-001'] = {'input': i, 'outputs': {'plan': p, 'baseline': base,
        'interest_difference': base['total_interest']-p['total_interest']}}
    i = {'principal': 120000, 'annual_pct': '4.8', 'months': 24,
         'rates': [{'month':4,'annual_pct':'3.6'}], 'events': [ev(4,20000,'reduce')]}
    a = simulate(**i); b = simulate(**i,early_order=True)
    comparison = []
    for m in (3,4,5,24):
        comparison.append({'month':m,'a_interest':row(a,m)['interest'],'b_interest':row(b,m)['interest'],
            'a_normal':row(a,m).get('normal',ZERO),'b_normal':row(b,m).get('normal',ZERO),
            'a_closing':row(a,m)['closing'],'b_closing':row(b,m)['closing']})
    out['DJ2-002'] = {'input': {**i,'B_order':'当月额外还本先于整月计息，之后调率、重算当期正常付款；仅文内构造'},
        'outputs': {'standard_A':a,'independent_B':b,'comparison':comparison,
                    'interest_difference_A_minus_B':a['total_interest']-b['total_interest']}}
    i = {'principal':60000,'annual_pct':'6','months':12,'events':[ev(2,12000),ev(5,6000,'reduce')]}
    p = simulate(**i); all_reduce = simulate(60000,'6',12,events=[ev(2,12000,'reduce'),ev(5,6000,'reduce')])
    out['DJ2-003'] = {'input':i,'outputs':{'mixed':p,'both_reduce':all_reduce}}
    # 奖金计划：先按原正常计划取得每月正常付款，再以同一家庭现金路径选额外额。
    bonuses = {12:50000,24:20000,36:45000}
    annual_costs = {12:15000,24:25000,36:20000}
    def budget_plan(policy):
        events=[]; cash=D(30000); ledger=[]; loan=simulate(360000,'3.6',60)
        for m in range(1,37):
            normal=row(loan,m).get('normal',ZERO)
            before=cash+D(15000)-D(8000)-normal+D(bonuses.get(m,0))-D(annual_costs.get(m,0))
            extra=ZERO
            if m in bonuses:
                extra=D(30000) if policy=='fixed' else max(ZERO,before-D(30000))
                events.append(ev(m,str(extra)))
                loan=simulate(360000,'3.6',60,events=events)
                extra=row(loan,m)['extra']
            cash=before-extra
            ledger.append({'month':m,'opening_cash':ledger[-1]['closing_cash'] if ledger else D(30000),
                'income':D(15000),'living':D(8000),'normal':normal,'bonus':D(bonuses.get(m,0)),
                'annual_cost':D(annual_costs.get(m,0)),'before_extra':before,'extra':extra,'closing_cash':cash,
                'below_floor':max(ZERO,D(30000)-cash),'loan_closing':row(loan,m)['closing']})
        totals={k:sum((r[k] for r in ledger),ZERO) for k in ('income','living','normal','bonus','annual_cost','extra')}
        assert D(30000)+totals['income']+totals['bonus']-totals['living']-totals['normal']-totals['annual_cost']-totals['extra']==cash
        return {'cash_rows':ledger,'loan':loan,'minimum_cash':min(r['closing_cash'] for r in ledger),
                'end_cash':cash,'events':events,'cash_totals':totals,'total_extra_36':totals['extra']}
    out['DJ2-004']={'input':{'principal':360000,'annual_pct':'3.6','months':60,'opening_cash':30000,
        'monthly_income':15000,'monthly_living':8000,'cash_floor':30000,'bonuses':bonuses,'annual_costs':annual_costs,
        'observation_months':36,'fixed_extra':30000,'event_mode':'shorten','cash_interest':0},
        'outputs':{'fixed':budget_plan('fixed'),'surplus':budget_plan('surplus')}}
    i={'principal':10000,'annual_pct':'12','months':6,'events':[ev(2,9000),ev(4,2000)]}
    p=simulate(**i)
    out['DJ2-005']={'input':{**i,'opening_cash':15000},'outputs':{'plan':p,'cash_after_payoff':D(15000)-p['total_cash'],
        'wrong_cash_if_all_requested_debited':D(15000)-sum((r['normal'] for r in p['rows']),ZERO)-D(11000)}}
    base=simulate(120000,'6',24); p=simulate(120000,'6',24,events=[ev(3,30000,'reduce',900)])
    assert max(D(300),p['total_extra']*D('0.03'))==p['total_fees']==D(900)
    cumulative=ZERO; fee_rows=[]
    for m in range(1,25):
        delta=row(base,m)['interest']-row(p,m)['interest']; cumulative+=delta
        fee_rows.append({'month':m,'baseline_interest':row(base,m)['interest'],'event_interest':row(p,m)['interest'],
            'interest_difference':delta,'cumulative_difference':cumulative,'net_after_fee':cumulative-D(900)})
    thresholds=[{'fee':D(f),'first_month':next((r['month'] for r in fee_rows if r['month']>=3 and r['cumulative_difference']>=D(f)),None),
                 'lifetime_net':cumulative-D(f)} for f in (0,900,10000)]
    out['DJ2-006']={'input':{'principal':120000,'annual_pct':'6','months':24,'events':[ev(3,30000,'reduce',900)],
        'fee_rule':'构造：max(300元,实际额外还本的3%)，额外还本同月另付','comparison_fees':[0,900,10000]},
        'outputs':{'baseline':base,'event_plan':p,'monthly_comparison':fee_rows,'thresholds':thresholds}}
    planned=simulate(120000,'6',24,events=[ev(4,20000),ev(10,10000,'reduce')])
    delayed=simulate(120000,'6',24,events=[ev(7,20000),ev(10,10000,'reduce')])
    cancelled=simulate(120000,'6',24,events=[ev(10,10000,'reduce')])
    comparisons=[]
    for m in (4,7,10):
        comparisons.append({'month':m,'planned_balance':row(planned,m)['closing'],'delayed_balance':row(delayed,m)['closing'],
            'cancelled_balance':row(cancelled,m)['closing'],'delayed_minus_planned':row(delayed,m)['closing']-row(planned,m)['closing'],
            'cancelled_minus_planned':row(cancelled,m)['closing']-row(planned,m)['closing']})
    out['DJ2-007']={'input':{'principal':120000,'annual_pct':'6','months':24,'planned_events':[ev(4,20000),ev(10,10000,'reduce')],
        'delayed_events':[ev(7,20000),ev(10,10000,'reduce')],'cancelled_events':[ev(10,10000,'reduce')],'cash_interest':0},
        'outputs':{'baseline':base,'planned':planned,'delayed':delayed,'cancelled':cancelled,'balance_comparison':comparisons,
        'interest_savings':{k:base['total_interest']-v['total_interest'] for k,v in [('planned',planned),('delayed',delayed),('cancelled',cancelled)]},
        'delayed_extra_interest':delayed['total_interest']-planned['total_interest']}}
    a=simulate(120000,'4.8',24,events=[ev(3,20000),ev(8,5000,'reduce')])
    b=simulate(80000,'3',24,method='principal',events=[ev(3,10000,'reduce'),ev(8,5000)])
    a2=simulate(120000,'4.8',24,events=[ev(3,30000),ev(8,10000,'reduce')])
    b2=simulate(80000,'3',24,method='principal')
    def combine(a,b):
        rows=[]
        for m in range(1,max(a['payoff_month'],b['payoff_month'])+1):
            ar=row(a,m);br=row(b,m)
            rows.append({'month':m,'a_normal':ar.get('normal',ZERO),'b_normal':br.get('normal',ZERO),
                'a_extra':ar.get('extra',ZERO),'b_extra':br.get('extra',ZERO),'cash':ar['cash']+br['cash'],
                'balance':ar['closing']+br['closing']})
        assert sum((r['cash'] for r in rows),ZERO)==a['total_cash']+b['total_cash']
        assert rows[-1]['balance']==0
        return {'rows':rows,'total_interest':a['total_interest']+b['total_interest'],
                'total_cash':a['total_cash']+b['total_cash'],'payoff_month':len(rows),'total_extra':a['total_extra']+b['total_extra']}
    out['DJ2-008']={'input':{'A':{'principal':120000,'annual_pct':'4.8','months':24,'method':'annuity',
        'events':[ev(3,20000),ev(8,5000,'reduce')]},'B':{'principal':80000,'annual_pct':'3','months':24,'method':'principal',
        'events':[ev(3,10000,'reduce'),ev(8,5000)]},'alternate_A_events':[ev(3,30000),ev(8,10000,'reduce')],
        'alternate_B_events':[],'fees':0},'outputs':{'A':a,'B':b,'combined':combine(a,b),
        'alternate_A':a2,'alternate_B':b2,'alternate_combined':combine(a2,b2)}}
    i={'principal':24000,'annual_pct':'6','months':12,'method':'principal','rates':[{'month':4,'annual_pct':'3.6'}],
       'events':[ev(2,5000,'shorten',30),ev(5,3000,'reduce',20)]}
    p=simulate(**i);base=simulate(24000,'6',12,method='principal',rates=i['rates'])
    sums=[]
    for start,end in ((1,2),(3,5),(6,p['payoff_month'])):
        rr=p['rows'][start-1:end]
        sums.append({'start':start,'end':end,'opening':rr[0]['opening'],'normal_principal':sum((r['normal_principal'] for r in rr),ZERO),
            'extra':sum((r['extra'] for r in rr),ZERO),'interest':sum((r['interest'] for r in rr),ZERO),
            'fees':sum((r['fee'] for r in rr),ZERO),'cash':sum((r['cash'] for r in rr),ZERO),'closing':rr[-1]['closing']})
    out['DJ2-009']={'input':i,'outputs':{'plan':p,'baseline':base,'segment_audit':sums,
        'interest_difference':base['total_interest']-p['total_interest'],
        'net_cost_difference':base['total_cash']-p['total_cash']}}
    # 结构与守恒反例：零利率、同月同模式合并、超额、等本金调率不改变q。
    z=simulate(100,0,3,events=[ev(1,30,'reduce')]);assert z['total_interest']==0 and z['total_principal']==100
    x=simulate(1000,0,10,events=[ev(2,100),ev(2,200)]);y=simulate(1000,0,10,events=[ev(2,300)])
    assert x['rows']==y['rows']
    assert out['DJ2-005']['outputs']['plan']['unused_extra']>0
    assert p['rows'][3]['normal_principal']==2000
    tiny=simulate(1,0,7,events=[ev(1,'0.01')])
    assert tiny['payoff_month']==7 and tiny['rows'][-1]['normal']==D('0.15')
    unchanged=simulate(1000,'3.6',12,events=[ev(2,0,'reduce')])
    noevent=simulate(1000,'3.6',12)
    assert unchanged['total_interest']==noevent['total_interest'] and unchanged['total_cash']==noevent['total_cash']
    fee_after_normal=simulate('0.10',0,1,events=[ev(1,1,'shorten','0.20'),ev(2,1,'shorten',2)])
    assert fee_after_normal['total_extra']==0 and fee_after_normal['total_fees']==D('0.20')
    assert fee_after_normal['skipped_events'][0]['fee']==0
    assumptions={'interest':'期初有效年利率除12，期初本金计息，利息按分half-up',
        'cash':'正常付款按分half-up，本金=正常付款-利息；末期归还剩余本金',
        'order':'期初调率→正常计息与付款→额外还本；DJ2-002 B为独立另序对照',
        'shorten':'保留正常月供/每期还本额，模拟整数期且不超当前到期月，允许缩0期',
        'reduce':'保留当前到期月重算下一期计划；实际额外还本为0不重排',
        'fee':'月初仍有贷款时按已录入独立费用扣现金；更早结清后事件费用不再扣',
        'sample':'全部金额、利率、日期与条款均为原创构造；无日息、预测或真实合同认定'}
    for record in out.values():
        record['input']['model_assumptions']=assumptions
        if 'principal' in record['input']:
            record['input'].setdefault('method','annuity')
    out['DJ2-001']['input']['baseline_events']=[]
    out['DJ2-003']['input']['both_reduce_events']=[ev(2,12000,'reduce'),ev(5,6000,'reduce')]
    out['DJ2-006']['input']['baseline_events']=[]
    out['DJ2-007']['input']['baseline_events']=[]
    out['DJ2-009']['input']['baseline_events']=[]
    return out

def serial(v):
    if isinstance(v,D): return format(v.quantize(CENT,rounding=ROUND_HALF_UP),'f')
    raise TypeError(type(v).__name__)

def verify_article_tables(result):
    """可选仓库内核对：把正文每张表的全部数字逐行与独立结果对照。"""
    x={k:v['outputs'] for k,v in result.items()}
    def fields(rows,keys,months=None):
        return [[r[k] for k in keys] for r in rows if months is None or r['month'] in months]
    def rows(id,key,keys,months=None):return fields(x[id][key]['rows'],keys,months)
    main=['month','opening','interest','normal','normal_principal','extra','closing']
    expected={}
    y=x['DJ2-001']['plan']
    expected['DJ2-001']=[rows('DJ2-001','plan',main,[1,3,4,8,9,12,13,22]),
        fields(y['rows'],['month','previous_end','planned_end','next_payment_or_q'],[3,8,12])]
    expected['DJ2-002']=[fields(x['DJ2-002']['comparison'],
        ['month','a_interest','b_interest','a_normal','b_normal','a_closing','b_closing'])]
    expected['DJ2-003']=[rows('DJ2-003','mixed',main),
        [[x['DJ2-003'][k][f] for f in ['total_normal_principal','total_extra','total_interest','payoff_month']]
         for k in ['mixed','both_reduce']]]
    y=x['DJ2-004']
    expected['DJ2-004']=[[v for k in ['fixed','surplus'] for v in fields(y[k]['cash_rows'],
        ['month','before_extra','bonus','annual_cost','extra','closing_cash','loan_closing'],[12,24,36])],
        [[36,y['fixed']['total_extra_36'],y['surplus']['total_extra_36']],
         [y['fixed']['minimum_cash'],y['surplus']['minimum_cash']],
         [36,y['fixed']['end_cash'],y['surplus']['end_cash']],
         [36,y['fixed']['loan']['rows'][35]['closing'],y['surplus']['loan']['rows'][35]['closing']],
         [y['fixed']['loan']['payoff_month'],y['surplus']['loan']['payoff_month']],
         [y['fixed']['loan']['total_interest'],y['surplus']['loan']['total_interest']]]]
    y=x['DJ2-005']['plan']
    expected['DJ2-005']=[fields(y['rows'],['month','opening','interest','normal','normal_principal','requested_extra','extra','closing']),
        [[2,9000,y['rows'][1]['extra'],y['rows'][1]['unused_extra']],[4,2000,0,2000],[11000,y['total_extra'],y['unused_extra']]]]
    y=x['DJ2-006']
    expected['DJ2-006']=[fields(y['monthly_comparison'],['month','baseline_interest','event_interest',
        'interest_difference','cumulative_difference','net_after_fee'],range(3,12)),
        [[t['fee']]+([t['first_month']] if t['first_month'] is not None else [])+[t['lifetime_net']] for t in y['thresholds']]]
    y=x['DJ2-007']
    expected['DJ2-007']=[fields(y['balance_comparison'],['month','planned_balance','delayed_balance','cancelled_balance',
        'delayed_minus_planned','cancelled_minus_planned']),
        [[y['baseline']['total_extra'],24,y['baseline']['total_interest'],0],
         [y['planned']['total_extra'],20,y['planned']['total_interest'],y['interest_savings']['planned']],
         [7,y['delayed']['total_extra'],20,y['delayed']['total_interest'],y['interest_savings']['delayed']],
         [y['cancelled']['total_extra'],24,y['cancelled']['total_interest'],y['interest_savings']['cancelled']]]]
    y=x['DJ2-008']
    expected['DJ2-008']=[[[120000,'4.8',20000,5000],[80000,'3.0',10000,5000]],
        fields(y['combined']['rows'],['month','a_normal','b_normal','a_extra','b_extra','cash','balance'],[1,3,4,8,9,20,21,23]),
        [[y['A']['total_interest'],y['alternate_A']['total_interest']],
         [y['B']['total_interest'],y['alternate_B']['total_interest']],
         [y['combined']['total_interest'],y['alternate_combined']['total_interest']],
         [y['combined']['total_cash'],y['alternate_combined']['total_cash']],
         [y['A']['payoff_month'],y['alternate_A']['payoff_month']],
         [y['B']['payoff_month'],y['alternate_B']['payoff_month']],
         [y['combined']['payoff_month'],y['alternate_combined']['payoff_month']]]]
    y=x['DJ2-009']
    expected['DJ2-009']=[fields(y['plan']['rows'],['month','opening','interest','normal_principal','normal','extra','fee','closing']),
        [[r['start'],r['end']]+[r[k] for k in ['opening','normal_principal','extra','interest','fees','cash','closing']]
         for r in y['segment_audit']]]
    root=HERE.parents[4]
    plan=json.loads((HERE.parent/'content-plan.json').read_text('utf-8'))['articles']
    checks=[]
    for r in plan:
        if r['cluster']!='R01':continue
        f=root/'sites/daojijun.com/src/content/article'/(r['planned_path'].strip('/').split('/')[-1]+'.md')
        core=f.read_text('utf-8').split('---',2)[2].split('<!-- daojijun-round2-evidence:start -->')[0]
        tables=re.findall(r'(?:^\|.*\|\n?)+',core,re.M)
        assert len(tables)==len(expected[r['id']]),(r['id'],'数据表数量不一致')
        for ti,(table,target) in enumerate(zip(tables,expected[r['id']]),1):
            numeric_rows=[[D(v) for v in re.findall(r'-?\d+(?:\.\d+)?',line)] for line in table.splitlines()[2:]]
            expected_rows=[[D(str(v)) for v in row] for row in target]
            assert numeric_rows==expected_rows,(r['id'],ti,'正文表格数值与独立结果不符')
            checks.append({'id':r['id'],'table':ti,'rows':len(numeric_rows),
                'numeric_cells':sum(map(len,numeric_rows)),'status':'逐行全部数值与独立JSON匹配'})
    return checks

if __name__=='__main__':
    parser=argparse.ArgumentParser()
    parser.add_argument('--verify-articles',action='store_true',help='仅仓库内：逐表核对R01正文全部数值')
    args=parser.parse_args()
    result=build()
    target=HERE/'calc_r01.json'
    target.write_text(json.dumps(result,ensure_ascii=False,indent=2,default=serial)+'\n','utf-8')
    if args.verify_articles:
        checks=verify_article_tables(result)
        print(json.dumps({'tables':len(checks),'rows':sum(r['rows'] for r in checks),
            'numeric_cells':sum(r['numeric_cells'] for r in checks),'passed':True},ensure_ascii=False))
    print('R01：九个编号、完整逐月输出及本金/现金守恒检查通过；'+str(target))