# Copyright 2017-present Gregory Szorc <gregory.szorc@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

"""generate release notes from commit messages (EXPERIMENTAL)

It is common to maintain files detailing changes in a project between

releases. Maintaining these files can be difficult and time consuming.

The :hg:`releasenotes` command provided by this extension makes the

process simpler by automating it.

"""

from __future__ import absolute_import

import errno

import re

import sys

import textwrap

from mercurial.i18n import _

from mercurial import (

    config,

    error,

    minirst,

    registrar,

    scmutil,

    util,

)

cmdtable = {}

command = registrar.command(cmdtable)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for

# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should

# be specifying the version(s) of Mercurial they are tested with, or

# leave the attribute unspecified.

testedwith = 'ships-with-hg-core'

DEFAULT_SECTIONS = [

    ('feature', _('New Features')),

    ('bc', _('Backwards Compatibility Changes')),

    ('fix', _('Bug Fixes')),

    ('perf', _('Performance Improvements')),

    ('api', _('API Changes')),

]

RE_DIRECTIVE = re.compile('^\.\. ([a-zA-Z0-9_]+)::\s*([^$]+)?$')

BULLET_SECTION = _('Other Changes')

class parsedreleasenotes(object):

    def __init__(self):

        self.sections = {}

    def __contains__(self, section):

        return section in self.sections

    def __iter__(self):

        return iter(sorted(self.sections))

    def addtitleditem(self, section, title, paragraphs):

        """Add a titled release note entry."""

        self.sections.setdefault(section, ([], []))

        self.sections[section][0].append((title, paragraphs))

    def addnontitleditem(self, section, paragraphs):

        """Adds a non-titled release note entry.

        Will be rendered as a bullet point.

        """

        self.sections.setdefault(section, ([], []))

        self.sections[section][1].append(paragraphs)

    def titledforsection(self, section):

        """Returns titled entries in a section.

        Returns a list of (title, paragraphs) tuples describing sub-sections.

        """

        return self.sections.get(section, ([], []))[0]

    def nontitledforsection(self, section):

        """Returns non-titled, bulleted paragraphs in a section."""

        return self.sections.get(section, ([], []))[1]

    def hastitledinsection(self, section, title):

        return any(t[0] == title for t in self.titledforsection(section))

    def merge(self, ui, other):

        """Merge another instance into this one.

        This is used to combine multiple sources of release notes together.

        """

        for section in other:

            for title, paragraphs in other.titledforsection(section):

                if self.hastitledinsection(section, title):

                    # TODO prompt for resolution if different and running in

                    # interactive mode.

                    ui.write(_('%s already exists in %s section; ignoring\n') %

                             (title, section))

                    continue

                self.addtitleditem(section, title, paragraphs)

            for paragraphs in other.nontitledforsection(section):

                if paragraphs in self.nontitledforsection(section):

                    continue

                self.addnontitleditem(section, paragraphs)

class releasenotessections(object):

    def __init__(self, ui, repo=None):

        if repo:

            sections = util.sortdict(DEFAULT_SECTIONS)

            custom_sections = getcustomadmonitions(repo)

            if custom_sections:

                sections.update(custom_sections)

            self._sections = list(sections.iteritems())

        else:

            self._sections = list(DEFAULT_SECTIONS)

    def __iter__(self):

        return iter(self._sections)

    def names(self):

        return [t[0] for t in self._sections]

    def sectionfromtitle(self, title):

        for name, value in self._sections:

            if value == title:

                return name

        return None

def getcustomadmonitions(repo):

    ctx = repo['.']

    p = config.config()

    def read(f, sections=None, remap=None):

        if f in ctx:

            data = ctx[f].data()

            p.parse(f, data, sections, remap, read)

        else:

            raise error.Abort(_(".hgreleasenotes file \'%s\' not found") %

                              repo.pathto(f))

    if '.hgreleasenotes' in ctx:

        read('.hgreleasenotes')

    return p['sections']

def parsenotesfromrevisions(repo, directives, revs):

    notes = parsedreleasenotes()

    for rev in revs:

        ctx = repo[rev]

        blocks, pruned = minirst.parse(ctx.description(),

                                       admonitions=directives)

        for i, block in enumerate(blocks):

            if block['type'] != 'admonition':

                continue

            directive = block['admonitiontitle']

            title = block['lines'][0].strip() if block['lines'] else None

            if i + 1 == len(blocks):

                raise error.Abort(_('release notes directive %s lacks content')

                                  % directive)

            # Now search ahead and find all paragraphs attached to this

            # admonition.

            paragraphs = []

            for j in range(i + 1, len(blocks)):

                pblock = blocks[j]

                # Margin blocks may appear between paragraphs. Ignore them.

                if pblock['type'] == 'margin':

                    continue

                if pblock['type'] != 'paragraph':

                    raise error.Abort(_('unexpected block in release notes '

                                        'directive %s') % directive)

                if pblock['indent'] > 0:

                    paragraphs.append(pblock['lines'])

                else:

                    break

            # TODO consider using title as paragraph for more concise notes.

            if not paragraphs:

                raise error.Abort(_('could not find content for release note '

                                    '%s') % directive)

            if title:

                notes.addtitleditem(directive, title, paragraphs)

            else:

                notes.addnontitleditem(directive, paragraphs)

    return notes

def parsereleasenotesfile(sections, text):

    """Parse text content containing generated release notes."""

    notes = parsedreleasenotes()

    blocks = minirst.parse(text)[0]

    def gatherparagraphsbullets(offset, title=False):

        notefragment = []

        for i in range(offset + 1, len(blocks)):

            block = blocks[i]

            if block['type'] == 'margin':

                continue

            elif block['type'] == 'section':

                break

            elif block['type'] == 'bullet':

                if block['indent'] != 0:

                    raise error.Abort(_('indented bullet lists not supported'))

                if title:

                    lines = [l[1:].strip() for l in block['lines']]

                    notefragment.append(lines)

                    continue

                else:

                    lines = [[l[1:].strip() for l in block['lines']]]

                    for block in blocks[i + 1:]:

                        if block['type'] in ('bullet', 'section'):

                            break

                        if block['type'] == 'paragraph':

                            lines.append(block['lines'])

                    notefragment.append(lines)

                    continue

            elif block['type'] != 'paragraph':

                raise error.Abort(_('unexpected block type in release notes: '

                                    '%s') % block['type'])

            if title:

                notefragment.append(block['lines'])

        return notefragment

    currentsection = None

    for i, block in enumerate(blocks):

        if block['type'] != 'section':

            continue

        title = block['lines'][0]

        # TODO the parsing around paragraphs and bullet points needs some

        # work.

        if block['underline'] == '=':  # main section

            name = sections.sectionfromtitle(title)

            if not name:

                raise error.Abort(_('unknown release notes section: %s') %

                                  title)

            currentsection = name

            bullet_points = gatherparagraphsbullets(i)

            if bullet_points:

                for para in bullet_points:

                    notes.addnontitleditem(currentsection, para)

        elif block['underline'] == '-':  # sub-section

            if title == BULLET_SECTION:

                bullet_points = gatherparagraphsbullets(i)

                for para in bullet_points:

                    notes.addnontitleditem(currentsection, para)

            else:

                paragraphs = gatherparagraphsbullets(i, True)

                notes.addtitleditem(currentsection, title, paragraphs)

        else:

            raise error.Abort(_('unsupported section type for %s') % title)

    return notes

def serializenotes(sections, notes):

    """Serialize release notes from parsed fragments and notes.

    This function essentially takes the output of ``parsenotesfromrevisions()``

    and ``parserelnotesfile()`` and produces output combining the 2.

    """

    lines = []

    for sectionname, sectiontitle in sections:

        if sectionname not in notes:

            continue

        lines.append(sectiontitle)

        lines.append('=' * len(sectiontitle))

        lines.append('')

        # First pass to emit sub-sections.

        for title, paragraphs in notes.titledforsection(sectionname):

            lines.append(title)

            lines.append('-' * len(title))

            lines.append('')

            wrapper = textwrap.TextWrapper(width=78)

            for i, para in enumerate(paragraphs):

                if i:

                    lines.append('')

                lines.extend(wrapper.wrap(' '.join(para)))

            lines.append('')

        # Second pass to emit bullet list items.