#!/usr/bin/env python3

"""accrual-report - Status reports for accruals

accrual-report checks accruals (postings under Assets:Receivable and

Liabilities:Payable) for errors and metadata consistency, and reports any

problems on stderr. Then it writes a report about the status of those

accruals on stdout.

The typical way to run it is to pass an RT ticket number or invoice link as an

argument::

    # Report all accruals associated with RT#1230:

    accrual-report 1230

    # Report all accruals with the invoice link rt:45/670.

    accrual-report 45/670

    # Report all accruals with the invoice link Invoice980.pdf.

    accrual-report Invoice980.pdf

By default, to stay fast, accrual-report only looks for postings from the

beginning of the last fiscal year. You can search further back in history

by passing the ``--since`` argument. The argument can be a fiscal year, or

a negative number of how many years back to search::

    # Search for accruals since 2016

    accrual-report --since 2016 [search terms …]

    # Search for accruals from the beginning of three fiscal years ago

    accrual-report --since -3 [search terms …]

If you want to further limit what accruals are reported, you can match on

other metadata by passing additional arguments in ``name=value`` format.

You can pass any number of search terms. For example::

    # Report accruals associated with RT#1230 and Jane Doe

    accrual-report 1230 entity=Doe-Jane

accrual-report will automatically decide what kind of report to generate from

the results of your search. If the search matches a single outstanding payable,

it will write an outgoing approval report; otherwise, it writes a basic balance

report. You can request a specific report type with the ``--report-type``

option::

    # Write an outgoing approval report for all outstanding accruals for

    # Jane Doe, even if there's more than one

    accrual-report --report-type outgoing entity=Doe-Jane

"""

# Copyright © 2020  Brett Smith

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import argparse

import collections

import datetime

import enum

import re

import sys

from typing import (

    Callable,

    Dict,

    Iterable,

    Iterator,

    Mapping,

    NamedTuple,

    Optional,

    Sequence,

    Set,

    TextIO,

    Tuple,

)

from ..beancount_types import (

    Error,

    MetaKey,

    MetaValue,

    Transaction,

)

import rt

from beancount.parser import printer as bc_printer

from . import core

from .. import config as configmod

from .. import data

from .. import filters

from .. import rtutil

PostGroups = Mapping[Optional[MetaValue], core.RelatedPostings]

RTObject = Mapping[str, str]

class Account(NamedTuple):

    name: str

    balance_paid: Callable[[core.Balance], bool]

class AccrualAccount(enum.Enum):

    PAYABLE = Account('Liabilities:Payable', core.Balance.ge_zero)

    RECEIVABLE = Account('Assets:Receivable', core.Balance.le_zero)

    @classmethod

    def account_names(cls) -> Iterator[str]:

        return (acct.value.name for acct in cls)

    @classmethod

    def classify(cls, related: core.RelatedPostings) -> 'AccrualAccount':

        for account in cls:

            account_name = account.value.name

            if all(post.account.is_under(account_name) for post in related):

                return account

        raise ValueError("unrecognized account set in related postings")

    @classmethod

    def filter_paid_accruals(cls, groups: PostGroups) -> PostGroups:

        return {

            key: related

            for key, related in groups.items()

            if not cls.classify(related).value.balance_paid(related.balance())

        }

class BaseReport:

        self.out_file = out_file

    def _since_last_nonzero(self, posts: core.RelatedPostings) -> core.RelatedPostings:

        retval = core.RelatedPostings()

        for post in posts:

            if retval.balance().is_zero():

                retval.clear()

            retval.add(post)

        return retval

    def _report(self,

                invoice: str,

                posts: core.RelatedPostings,

                index: int,

    ) -> Iterable[str]:

        raise NotImplementedError("BaseReport._report")

    def run(self, groups: PostGroups) -> None:

        for index, invoice in enumerate(groups):

            for line in self._report(str(invoice), groups[invoice], index):

                print(line, file=self.out_file)

class BalanceReport(BaseReport):

    def _report(self,

                invoice: str,

                posts: core.RelatedPostings,

                index: int,

    ) -> Iterable[str]:

        posts = self._since_last_nonzero(posts)

        balance = posts.balance()

        date_s = posts[0].meta.date.strftime('%Y-%m-%d')

        if index:

            yield ""

        yield f"{invoice}:"

        yield f"  {balance} outstanding since {date_s}"

class OutgoingReport(BaseReport):

        self.rt_client = rt_client

        self.rt_wrapper = rtutil.RT(rt_client)

    def _primary_rt_id(self, posts: core.RelatedPostings) -> rtutil.TicketAttachmentIds:

        rt_ids = posts.all_meta_links('rt-id')

        rt_ids_count = len(rt_ids)

        if rt_ids_count != 1:

            raise ValueError(f"{rt_ids_count} rt-id links found")

        parsed = rtutil.RT.parse(rt_ids.pop())

        if parsed is None:

            raise ValueError("rt-id is not a valid RT reference")

        else:

            return parsed

    def _report(self,

                invoice: str,

                posts: core.RelatedPostings,

                index: int,

    ) -> Iterable[str]:

        posts = self._since_last_nonzero(posts)

        try:

            ticket_id, _ = self._primary_rt_id(posts)

            ticket = self.rt_client.get_ticket(ticket_id)

            # Note we only use this when ticket is None.

            errmsg = f"ticket {ticket_id} not found"

        except (ValueError, rt.RtError) as error:

            ticket = None

            errmsg = error.args[0]

        if ticket is None:

            return

        try:

            rt_requestor = self.rt_client.get_user(ticket['Requestors'][0])

        except (IndexError, rt.RtError):

            rt_requestor = None

        if rt_requestor is None:

            requestor = ''

            requestor_name = ''

        else:

            requestor_name = (

                rt_requestor.get('RealName')

                or ticket.get('CF.{payment-to}')

                or ''

            )

            requestor = f'{requestor_name} <{rt_requestor["EmailAddress"]}>'.strip()

        raw_balance = -posts.balance()

        cost_balance = -posts.balance_at_cost()

        cost_balance_s = cost_balance.format(None)

        if raw_balance == cost_balance:

            balance_s = cost_balance_s

        else:

            balance_s = f'{raw_balance} ({cost_balance_s})'

        contract_links = posts.all_meta_links('contract')

        if contract_links:

            contract_s = ' , '.join(self.rt_wrapper.iter_urls(

                contract_links, missing_fmt='<BROKEN RT LINK: {}>',

            ))

        else:

            contract_s = "NO CONTRACT GOVERNS THIS TRANSACTION"

        projects = [v for v in posts.meta_values('project')

                    if isinstance(v, str)]

        yield "PAYMENT FOR APPROVAL:"

        yield f"REQUESTOR: {requestor}"

        yield f"TOTAL TO PAY: {balance_s}"

        yield f"AGREEMENT: {contract_s}"

        yield f"PAYMENT TO: {ticket.get('CF.{payment-to}') or requestor_name}"

        yield f"PAYMENT METHOD: {ticket.get('CF.{payment-method}', '')}"

        yield f"PROJECT: {', '.join(projects)}"

        yield "\nBEANCOUNT ENTRIES:\n"

        last_txn: Optional[Transaction] = None

        for post in posts:

            txn = post.meta.txn

            if txn is not last_txn:

                last_txn = txn

                txn = self.rt_wrapper.txn_with_urls(txn, '{}')

                yield bc_printer.format_entry(txn)

class ReportType(enum.Enum):

    BALANCE = BalanceReport

    OUTGOING = OutgoingReport

    BAL = BALANCE

    OUT = OUTGOING

    OUTGOINGS = OUTGOING

    @classmethod

    def by_name(cls, name: str) -> 'ReportType':

        try:

            return cls[name.upper()]

                key = 'rt-id' if attachment_id is None else 'invoice'

            pattern = rtutil.RT.metadata_regexp(

                ticket_id,

                attachment_id,

                first_link_only=key == 'rt-id' and attachment_id is None,

            )

        return cls(key, pattern)

def consistency_check(groups: PostGroups) -> Iterable[Error]:

    for key, related in groups.items():

        for checked_meta in ['contract', 'entity', 'purchase-order']:

            meta_values = related.meta_values(checked_meta)

            if len(meta_values) != 1:

                errmsg = f'inconsistent {checked_meta} for invoice {key}'

                for post in related:

                    yield Error(

                        post.meta,

                        f'{errmsg}: {post.meta.get(checked_meta)}',

                        post.meta.txn,

                    )

def filter_search(postings: Iterable[data.Posting],

                  search_terms: Iterable[SearchTerm],

) -> Iterable[data.Posting]:

    accounts = tuple(AccrualAccount.account_names())

    postings = (post for post in postings if post.account.is_under(*accounts))

    for meta_key, pattern in search_terms:

        postings = filters.filter_meta_match(postings, meta_key, re.compile(pattern))

    return postings

def parse_arguments(arglist: Optional[Sequence[str]]=None) -> argparse.Namespace:

    parser = argparse.ArgumentParser()

    parser.add_argument(

        '--report-type', '-t',

        metavar='NAME',

        type=ReportType.by_name,

        help="""The type of report to generate, either `balance` or `outgoing`.

If not specified, the default is `outgoing` for search criteria that return a

single outstanding payable, and `balance` any other time.

""")

    parser.add_argument(

        '--since',

        metavar='YEAR',

        type=int,

        default=-1,

        help="""How far back to search the books for related transactions.

You can either specify a fiscal year, or a negative offset from the current

fiscal year, to start loading entries from. The default is -1 (start from the

previous fiscal year).

""")

    parser.add_argument(

        'search',

        nargs=argparse.ZERO_OR_MORE,

        help="""Report on accruals that match this criteria. The format is

NAME=TERM. TERM is a link or word that must exist in a posting's NAME

metadata to match. A single ticket number is a shortcut for

`rt-id=rt:NUMBER`. Any other link, including an RT attachment link in

`TIK/ATT` format, is a shortcut for `invoice=LINK`.

""")

    args = parser.parse_args(arglist)

    args.search_terms = [SearchTerm.parse(s) for s in args.search]

    return args

def main(arglist: Optional[Sequence[str]]=None,

         stdout: TextIO=sys.stdout,

         stderr: TextIO=sys.stderr,

         config: Optional[configmod.Config]=None,

) -> int:

    returncode = 0

    args = parse_arguments(arglist)

    if config is None:

        config = configmod.Config()

        config.load_file()

    books_loader = config.books_loader()

    if books_loader is not None:

        entries, load_errors, _ = books_loader.load_fy_range(args.since)

    else:

        entries = []

        source = {

            'filename': str(config.config_file_path()),

            'lineno': 1,

        }

        load_errors = [Error(source, "no books to load in configuration", None)]

    postings = filter_search(data.Posting.from_entries(entries), args.search_terms)

    groups = core.RelatedPostings.group_by_meta(postings, 'invoice')

    groups = AccrualAccount.filter_paid_accruals(groups) or groups

    meta_errors = consistency_check(groups)

    for error in load_errors:

        bc_printer.print_error(error, file=stderr)

        returncode |= ReturnFlag.LOAD_ERRORS

    for error in meta_errors:

        bc_printer.print_error(error, file=stderr)

        returncode |= ReturnFlag.CONSISTENCY_ERRORS

    if args.report_type is None:

        args.report_type = ReportType.default_for(groups)

    if not groups:

        returncode |= ReturnFlag.NOTHING_TO_REPORT

    report: Optional[BaseReport] = None

    if args.report_type is ReportType.OUTGOING:

        rt_client = config.rt_client()

        if rt_client is None:

        else:

    else:

    if report is None:

        returncode |= ReturnFlag.REPORT_ERRORS

    else:

        report.run(groups)

    return 0 if returncode == 0 else 16 + returncode

if __name__ == '__main__':

    exit(main())

    # Raising ValueError helps argparse generate good messages.

    with pytest.raises(ValueError):

        accrual.ReportType.by_name(arg)

@pytest.mark.parametrize('meta_key,account', testutil.combine_values(

    CONSISTENT_METADATA,

    ACCOUNTS,

))

def test_consistency_check_when_consistent(meta_key, account):

    invoice = f'test-{meta_key}-invoice'

    meta = {

        'invoice': invoice,

        meta_key: f'test-{meta_key}-value',

    }

    txn = testutil.Transaction(postings=[

        (account, 100, meta),

        (account, -100, meta),

    ])

    related = core.RelatedPostings(data.Posting.from_txn(txn))

    assert not list(accrual.consistency_check({invoice: related}))

@pytest.mark.parametrize('meta_key,account', testutil.combine_values(

    ['approval', 'fx-rate', 'statement'],

    ACCOUNTS,

))

def test_consistency_check_ignored_metadata(meta_key, account):

    invoice = f'test-{meta_key}-invoice'

    txn = testutil.Transaction(postings=[

        (account, 100, {'invoice': invoice, meta_key: 'credit'}),

        (account, -100, {'invoice': invoice, meta_key: 'debit'}),

    ])

    related = core.RelatedPostings(data.Posting.from_txn(txn))

    assert not list(accrual.consistency_check({invoice: related}))

@pytest.mark.parametrize('meta_key,account', testutil.combine_values(

    CONSISTENT_METADATA,

    ACCOUNTS,

))

def test_consistency_check_when_inconsistent(meta_key, account):

    invoice = f'test-{meta_key}-invoice'

    txn = testutil.Transaction(postings=[

        (account, 100, {'invoice': invoice, meta_key: 'credit', 'lineno': 1}),

        (account, -100, {'invoice': invoice, meta_key: 'debit', 'lineno': 2}),

    ])

    related = core.RelatedPostings(data.Posting.from_txn(txn))

    errors = list(accrual.consistency_check({invoice: related}))

    for exp_lineno, (actual, exp_msg) in enumerate(itertools.zip_longest(errors, [

            f'inconsistent {meta_key} for invoice {invoice}: credit',

            f'inconsistent {meta_key} for invoice {invoice}: debit',

    ]), 1):

        assert actual.message == exp_msg

        assert actual.entry is txn

        assert actual.source.get('lineno') == exp_lineno

def check_output(output, expect_patterns):

    output.seek(0)

    testutil.check_lines_match(iter(output), expect_patterns)

def run_outgoing(invoice, postings, rt_client=None):

    if rt_client is None:

        rt_client = RTClient()

    if not isinstance(postings, core.RelatedPostings):

        postings = relate_accruals_by_meta(postings, invoice)

    output = io.StringIO()

    report.run({invoice: postings})

@pytest.mark.parametrize('invoice,expected', [

    ('rt:505/5050', "Zero balance outstanding since 2020-05-05"),

    ('rt:510/5100', "Zero balance outstanding since 2020-05-10"),

    ('rt:510/6100', "-280.00 USD outstanding since 2020-06-10"),

    ('rt://ticket/515/attachments/5150', "1,500.00 USD outstanding since 2020-05-15",),

])

    related = relate_accruals_by_meta(accrual_postings, invoice)

    output = io.StringIO()

    report.run({invoice: related})

    check_output(output, [invoice, expected])

    invoice = 'rt:510/6100'

    rt_url = RTClient.DEFAULT_URL[:-9]

    rt_id_url = rf'\b{re.escape(f"{rt_url}Ticket/Display.html?id=510")}\b'

    contract_url = rf'\b{re.escape(f"{rt_url}Ticket/Attachment/4000/4000/contract.pdf")}\b'

    check_output(output, [

        r'^PAYMENT FOR APPROVAL:$',

        r'^REQUESTOR: Mx\. 510 <mx510@example\.org>$',

        r'^TOTAL TO PAY: \$280\.00$',

        fr'^AGREEMENT: {contract_url}',

        r'^PAYMENT TO: Hon\. Mx\. 510$',

        r'^PAYMENT METHOD: payment method 510$',

        r'^BEANCOUNT ENTRIES:$',

        # For each transaction, check for the date line, a metadata, and the

        # Expenses posting.

        r'^\s*2020-06-10\s',

        fr'^\s+rt-id: "{rt_id_url}"$',

        r'^\s+Expenses:Services:Legal\s+220\.00 USD$',

        r'^\s*2020-06-12\s',

        fr'^\s+contract: "{contract_url}"$',

        r'^\s+Expenses:FilingFees\s+60\.00 USD$',

    ])

    invoice = 'rt:510/6100'

    rt_client = RTClient(want_cfs=False)

    check_output(output, [

        r'^PAYMENT FOR APPROVAL:$',

        r'^REQUESTOR: <mx510@example\.org>$',

        r'^PAYMENT TO:\s*$',

        r'^PAYMENT METHOD:\s*$',

    ])

    invoice = 'rt:520/5200'

    check_output(output, [

        r'^PAYMENT FOR APPROVAL:$',

        r'^REQUESTOR: Mx\. 520 <mx520@example\.org>$',

        r'^TOTAL TO PAY: 1,000\.00 EUR \(\$1,100.00\)$',

    ])

def run_main(arglist, config=None):

    if config is None:

        config = testutil.TestConfig(

            books_path=testutil.test_path('books/accruals.beancount'),

            rt_client=RTClient(),

        )

    output = io.StringIO()

    errors = io.StringIO()

    retcode = accrual.main(arglist, output, errors, config)

    return retcode, output, errors

def check_main_fails(arglist, config, error_flags, error_patterns):

    retcode, output, errors = run_main(arglist, config)

    assert retcode > 16

    assert (retcode - 16) & error_flags

    check_output(errors, error_patterns)

    assert not output.getvalue()

@pytest.mark.parametrize('arglist', [

    ['--report-type=balance'],

    ['--report-type=outgoing'],

    ['entity=EarlyBird'],

])

def test_output_excludes_payments(arglist):

    retcode, output, errors = run_main(arglist)

    assert not errors.getvalue()

    assert retcode == 0

    output.seek(0)

    for line in output:

        assert not re.match(r'\brt:4\d\b', line)

@pytest.mark.parametrize('arglist,expect_invoice', [

    (['40'], 'rt:40/400'),

    (['44/440'], 'rt:44/440'),

])

def test_output_payments_when_only_match(arglist, expect_invoice):

    retcode, output, errors = run_main(arglist)

    assert not errors.getvalue()

    assert retcode == 0

    check_output(output, [

        rf'^{re.escape(expect_invoice)}:$',

        r' outstanding since ',

    ])

@pytest.mark.parametrize('arglist', [

    ['--report-type=outgoing'],

    ['510'],

    ['510/6100'],

    ['entity=Lawyer'],

])

def test_main_outgoing_report(arglist):

    retcode, output, errors = run_main(arglist)

    assert not errors.getvalue()

    assert retcode == 0

    rt_url = RTClient.DEFAULT_URL[:-9]

    rt_id_url = re.escape(f'<{rt_url}Ticket/Display.html?id=510>')

    contract_url = re.escape(f'<{rt_url}Ticket/Attachment/4000/4000/contract.pdf>')

    check_output(output, [

        r'^REQUESTOR: Mx\. 510 <mx510@example\.org>$',

        r'^TOTAL TO PAY: \$280\.00$',

        r'^\s*2020-06-12\s',

        r'^\s+Expenses:FilingFees\s+60\.00 USD$',

    ])

@pytest.mark.parametrize('arglist', [

    ['-t', 'balance'],

    ['515'],

    ['515/5150'],

    ['entity=DonorB'],

])

def test_main_balance_report(arglist):

    retcode, output, errors = run_main(arglist)

    assert not errors.getvalue()

    assert retcode == 0

    check_output(output, [

        r'\brt://ticket/515/attachments/5150:$',

        r'^\s+1,500\.00 USD outstanding since 2020-05-15$',

    ])

def test_main_no_books():

    check_main_fails([], testutil.TestConfig(), 1 | 8, [

        r':1: +no books to load in configuration\b',

    ])

@pytest.mark.parametrize('arglist', [

    ['499'],

    ['505/99999'],

    ['entity=NonExistent'],

])

def test_main_no_matches(arglist):

    check_main_fails(arglist, None, 8, [

    ])

def test_main_no_rt():

    config = testutil.TestConfig(

        books_path=testutil.test_path('books/accruals.beancount'),

    )

    check_main_fails(['-t', 'out'], config, 4, [

    ])