#!/usr/bin/env python
from __future__ import print_function

import glob
import os
import sys

verbose = '--verbose' in sys.argv
dump = '--dump' in sys.argv
internal = '--internal' in sys.argv
plain_output = '--plain-output' in sys.argv
if plain_output:
    plain_file = open('plain_text_out.txt', 'w+')
in_code = None

paths = ['include/libtorrent/*.hpp', 'include/libtorrent/kademlia/*.hpp', 'include/libtorrent/extensions/*.hpp']

if internal:
    paths.append('include/libtorrent/aux_/*.hpp')

files = []

for p in paths:
    files.extend(glob.glob(os.path.join('..', p)))

functions = []
classes = []
enums = []

# maps filename to overview description
overviews = {}

# maps names -> URL
symbols = {}

# some files that need pre-processing to turn symbols into
# links into the reference documentation
preprocess_rst = \
    {
        'manual.rst': 'manual-ref.rst',
        'upgrade_to_1.2.rst': 'upgrade_to_1.2-ref.rst',
        'settings.rst': 'settings-ref.rst'
    }

# some pre-defined sections from the main manual
symbols = \
    {
        "queuing_": "manual-ref.html#queuing",
        "fast-resume_": "manual-ref.html#fast-resume",
        "storage-allocation_": "manual-ref.html#storage-allocation",
        "alerts_": "manual-ref.html#alerts",
        "upnp-and-nat-pmp_": "manual-ref.html#upnp-and-nat-pmp",
        "http-seeding_": "manual-ref.html#http-seeding",
        "metadata-from-peers_": "manual-ref.html#metadata-from-peers",
        "magnet-links_": "manual-ref.html#magnet-links",
        "ssl-torrents_": "manual-ref.html#ssl-torrents",
        "dynamic-loading-of-torrent-files_": "manual-ref.html#dynamic-loading-of-torrent-files",
        "session-statistics_": "manual-ref.html#session-statistics",
        "peer-classes_": "manual-ref.html#peer-classes"
    }

static_links = \
    {
        ".. _`BEP 3`: https://bittorrent.org/beps/bep_0003.html",
        ".. _`BEP 17`: https://bittorrent.org/beps/bep_0017.html",
        ".. _`BEP 19`: https://bittorrent.org/beps/bep_0019.html"
    }

anon_index = 0

category_mapping = {
    'ed25519.hpp': 'ed25519',
    'session.hpp': 'Core',
    'add_torrent_params.hpp': 'Core',
    'session_status.hpp': 'Core',
    'error_code.hpp': 'Error Codes',
    'storage.hpp': 'Custom Storage',
    'storage_defs.hpp': 'Storage',
    'file_storage.hpp': 'Storage',
    'file_pool.hpp': 'Custom Storage',
    'extensions.hpp': 'Plugins',
    'ut_metadata.hpp': 'Plugins',
    'ut_pex.hpp': 'Plugins',
    'ut_trackers.hpp': 'Plugins',
    'smart_ban.hpp': 'Plugins',
    'create_torrent.hpp': 'Create Torrents',
    'alert.hpp': 'Alerts',
    'alert_types.hpp': 'Alerts',
    'bencode.hpp': 'Bencoding',
    'lazy_entry.hpp': 'Bencoding',
    'bdecode.hpp': 'Bdecoding',
    'entry.hpp': 'Bencoding',
    'time.hpp': 'Time',
    'escape_string.hpp': 'Utility',
    'enum_net.hpp': 'Network',
    'broadcast_socket.hpp': 'Network',
    'socket.hpp': 'Network',
    'socket_io.hpp': 'Network',
    'bitfield.hpp': 'Utility',
    'sha1_hash.hpp': 'Utility',
    'hasher.hpp': 'Utility',
    'hasher512.hpp': 'Utility',
    'identify_client.hpp': 'Utility',
    'ip_filter.hpp': 'Filter',
    'session_settings.hpp': 'Settings',
    'settings_pack.hpp': 'Settings',
    'operations.hpp': 'Alerts',
    'disk_buffer_holder.hpp': 'Custom Storage',
    'alert_dispatcher.hpp': 'Alerts',
}

category_fun_mapping = {
    'min_memory_usage()': 'Settings',
    'high_performance_seed()': 'Settings',
    'cache_status': 'Core',
}


def categorize_symbol(name, filename):
    f = os.path.split(filename)[1]

    if name.endswith('_category()') \
            or name.endswith('_error_code') \
            or name.endswith('error_code_enum'):
        return 'Error Codes'

    if name in category_fun_mapping:
        return category_fun_mapping[name]

    if f in category_mapping:
        return category_mapping[f]

    return 'Core'


def suppress_warning(filename, name):
    f = os.path.split(filename)[1]
    if f != 'alert_types.hpp':
        return False

    # if name.endswith('_alert') or name == 'message()':
    return True

    # return False


def first_item(itr):
    for i in itr:
        return i
    return None


def is_visible(desc):
    if desc.strip().startswith('hidden'):
        return False
    if internal:
        return True
    if desc.strip().startswith('internal'):
        return False
    return True


def highlight_signature(s):
    name = s.split('(', 1)
    name2 = name[0].split(' ')
    if len(name2[-1]) == 0:
        return s

    # make the name of the function bold
    name2[-1] = '**' + name2[-1] + '** '

    # if there is a return value, make sure we preserve pointer types
    if len(name2) > 1:
        name2[0] = name2[0].replace('*', '\\*')
    name[0] = ' '.join(name2)

    # we have to escape asterisks, since this is rendered into
    # a parsed literal in rst
    name[1] = name[1].replace('*', '\\*')

    # we also have to escape colons
    name[1] = name[1].replace(':', '\\:')

    # escape trailing underscores
    name[1] = name[1].replace('_', '\\_')

    # comments in signatures are italic
    name[1] = name[1].replace('/\\*', '*/\\*')
    name[1] = name[1].replace('\\*/', '\\*/*')
    return '('.join(name)


def html_sanitize(s):
    ret = ''
    for i in s:
        if i == '<':
            ret += '&lt;'
        elif i == '>':
            ret += '&gt;'
        elif i == '&':
            ret += '&amp;'
        else:
            ret += i
    return ret


def looks_like_namespace(line):
    line = line.strip()
    if line.startswith('namespace'):
        return True
    return False


def looks_like_blank(line):
    line = line.split('//')[0]
    line = line.replace('{', '')
    line = line.replace('}', '')
    line = line.replace('[', '')
    line = line.replace(']', '')
    line = line.replace(';', '')
    line = line.strip()
    return len(line) == 0


def looks_like_variable(line):
    line = line.split('//')[0]
    line = line.strip()
    if ' ' not in line and '\t' not in line:
        return False
    if line.startswith('friend '):
        return False
    if line.startswith('enum '):
        return False
    if line.startswith(','):
        return False
    if line.startswith(':'):
        return False
    if line.startswith('typedef'):
        return False
    if line.startswith('using'):
        return False
    if ' = ' in line:
        return True
    if line.endswith(';'):
        return True
    return False


def looks_like_forward_decl(line):
    line = line.split('//')[0]
    line = line.strip()
    if not line.endswith(';'):
        return False
    if '{' in line:
        return False
    if '}' in line:
        return False
    if line.startswith('friend '):
        return True
    if line.startswith('struct '):
        return True
    if line.startswith('class '):
        return True
    return False


def looks_like_function(line):
    if line.startswith('friend'):
        return False
    if '::' in line.split('(')[0].split(' ')[-1]:
        return False
    if line.startswith(','):
        return False
    if line.startswith(':'):
        return False
    return '(' in line


def parse_function(lno, lines, filename):

    start_paren = 0
    end_paren = 0
    signature = ''

    while lno < len(lines):
        line = lines[lno].strip()
        lno += 1
        if line.startswith('//'):
            continue

        start_paren += line.count('(')
        end_paren += line.count(')')

        sig_line = line.replace('TORRENT_EXPORT ', '').replace('TORRENT_EXTRA_EXPORT', '').strip()
        if signature != '':
            sig_line = '\n   ' + sig_line
        signature += sig_line
        if verbose:
            print('fun     %s' % line)

        if start_paren > 0 and start_paren == end_paren:
            if signature[-1] != ';':
                # we also need to consume the function body
                start_paren = 0
                end_paren = 0
                for i in range(len(signature)):
                    if signature[i] == '(':
                        start_paren += 1
                    elif signature[i] == ')':
                        end_paren += 1

                    if start_paren > 0 and start_paren == end_paren:
                        for k in range(i, len(signature)):
                            if signature[k] == ':' or signature[k] == '{':
                                signature = signature[0:k].strip()
                                break
                        break

                lno = consume_block(lno - 1, lines)
                signature += ';'
            ret = [{'file': filename[11:], 'signatures': set([signature]), 'names': set(
                [signature.split('(')[0].split(' ')[-1].strip() + '()'])}, lno]
            if first_item(ret[0]['names']) == '()':
                return [None, lno]
            return ret
    if len(signature) > 0:
        print('\x1b[31mFAILED TO PARSE FUNCTION\x1b[0m %s\nline: %d\nfile: %s' % (signature, lno, filename))
    return [None, lno]


def parse_class(lno, lines, filename):
    start_brace = 0
    end_brace = 0

    name = ''
    funs = []
    fields = []
    enums = []
    state = 'public'
    context = ''
    class_type = 'struct'
    blanks = 0
    decl = ''

    while lno < len(lines):
        line = lines[lno].strip()
        decl += lines[lno].replace('TORRENT_EXPORT ', '').replace('TORRENT_EXTRA_EXPORT', '').split('{')[0].strip()
        if '{' in line:
            break
        if verbose:
            print('class  %s' % line)
        lno += 1

    if decl.startswith('class'):
        state = 'private'
        class_type = 'class'

    name = decl.split(':')[0].replace('class ', '').replace('struct ', '').replace('final', '').strip()

    while lno < len(lines):
        line = lines[lno].strip()
        lno += 1

        if line == '':
            blanks += 1
            context = ''
            continue

        if line.startswith('/*'):
            lno = consume_comment(lno - 1, lines)
            continue

        if line.startswith('#'):
            lno = consume_ifdef(lno - 1, lines, True)
            continue

        if 'TORRENT_DEFINE_ALERT' in line:
            if verbose:
                print('xx    %s' % line)
            blanks += 1
            continue
        if 'TORRENT_DEPRECATED' in line:
            if verbose:
                print('xx    %s' % line)
            blanks += 1
            continue

        if line.startswith('//'):
            if verbose:
                print('desc  %s' % line)

            # plain output prints just descriptions and filters out c++ code.
            # it's used to run spell checker over
            if plain_output:
                s = line.split('//')[1]
                # if the first character is a space, strip it
                if len(s) > 0 and s[0] == ' ':
                    s = s[1:]
                global in_code
                if in_code is not None and not s.startswith(in_code) and len(s) > 1:
                    in_code = None

                if s.strip().startswith('.. code::'):
                    in_code = s.split('.. code::')[0] + '\t'

                # strip out C++ code from the plain text output since it's meant for
                # running spell checking over
                if not s.strip().startswith('.. ') and in_code is None:
                    plain_file.write(s + '\n')
            line = line[2:]
            if len(line) and line[0] == ' ':
                line = line[1:]
            context += line + '\n'
            continue

        start_brace += line.count('{')
        end_brace += line.count('}')

        if line == 'private:':
            state = 'private'
        elif line == 'protected:':
            state = 'protected'
        elif line == 'public:':
            state = 'public'

        if start_brace > 0 and start_brace == end_brace:
            return [{'file': filename[11:], 'enums': enums, 'fields':fields,
                     'type': class_type, 'name': name, 'decl': decl, 'fun': funs}, lno]

        if state != 'public' and not internal:
            if verbose:
                print('private %s' % line)
            blanks += 1
            continue

        if start_brace - end_brace > 1:
            if verbose:
                print('scope   %s' % line)
            blanks += 1
            continue

        if looks_like_function(line):
            current_fun, lno = parse_function(lno - 1, lines, filename)
            if current_fun is not None and is_visible(context):
                if context == '' and blanks == 0 and len(funs):
                    funs[-1]['signatures'].update(current_fun['signatures'])
                    funs[-1]['names'].update(current_fun['names'])
                else:
                    current_fun['desc'] = context
                    if context == '' and not suppress_warning(filename, first_item(current_fun['names'])):
                        print('WARNING: member function "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                              % (name + '::' + first_item(current_fun['names']), filename, lno))
                    funs.append(current_fun)
                context = ''
                blanks = 0
            continue

        if looks_like_variable(line):
            if verbose:
                print('var     %s' % line)
            if not is_visible(context):
                continue
            line = line.split('//')[0].strip()
            # the name may look like this:
            # std::uint8_t fails : 7;
            # int scrape_downloaded = -1;
            # static constexpr peer_flags_t interesting{0x1};
            n = line.split('=')[0].split('{')[0].strip().split(' : ')[0].split(' ')[-1].split(':')[0].split(';')[0]
            if context == '' and blanks == 0 and len(fields):
                fields[-1]['names'].append(n)
                fields[-1]['signatures'].append(line)
            else:
                if context == '' and not suppress_warning(filename, n):
                    print('WARNING: field "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                          % (name + '::' + n, filename, lno))
                fields.append({'signatures': [line], 'names': [n], 'desc': context})
            context = ''
            blanks = 0
            continue

        if line.startswith('enum '):
            if verbose:
                print('enum    %s' % line)
            if not is_visible(context):
                consume_block(lno - 1, lines)
            else:
                enum, lno = parse_enum(lno - 1, lines, filename)
                if enum is not None:
                    enum['desc'] = context
                    if context == '' and not suppress_warning(filename, enum['name']):
                        print('WARNING: enum "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                              % (name + '::' + enum['name'], filename, lno))
                    enums.append(enum)
                context = ''
            continue

        context = ''

        if verbose:
            if looks_like_forward_decl(line) \
                    or looks_like_blank(line) \
                    or looks_like_namespace(line):
                print('--      %s' % line)
            else:
                print('??      %s' % line)

    if len(name) > 0:
        print('\x1b[31mFAILED TO PARSE CLASS\x1b[0m %s\nfile: %s:%d' % (name, filename, lno))
    return [None, lno]


def parse_enum(lno, lines, filename):
    start_brace = 0
    end_brace = 0
    global anon_index

    line = lines[lno].strip()
    name = line.replace('enum ', '').split('{')[0].strip()
    if len(name) == 0:
        if not internal:
            print('WARNING: anonymous enum at: \x1b[34m%s:%d\x1b[0m' % (filename, lno))
            lno = consume_block(lno - 1, lines)
            return [None, lno]
        name = 'anonymous_enum_%d' % anon_index
        anon_index += 1

    values = []
    context = ''
    if '{' not in line:
        if verbose:
            print('enum  %s' % lines[lno])
        lno += 1

    val = 0
    while lno < len(lines):
        line = lines[lno].strip()
        lno += 1

        if line.startswith('//'):
            if verbose:
                print('desc  %s' % line)
            line = line[2:]
            if len(line) and line[0] == ' ':
                line = line[1:]
            context += line + '\n'
            continue

        if line.startswith('#'):
            lno = consume_ifdef(lno - 1, lines)
            continue

        start_brace += line.count('{')
        end_brace += line.count('}')

        if '{' in line:
            line = line.split('{')[1]
        line = line.split('}')[0]

        if len(line):
            if verbose:
                print('enumv %s' % lines[lno - 1])
            for v in line.split(','):
                v = v.strip()
                if v.startswith('//'):
                    break
                if v == '':
                    continue
                valstr = ''
                try:
                    if '=' in v:
                        val = int(v.split('=')[1].strip(), 0)
                    valstr = str(val)
                except BaseException:
                    pass

                if '=' in v:
                    v = v.split('=')[0].strip()
                if is_visible(context):
                    values.append({'name': v.strip(), 'desc': context, 'val': valstr})
                    if verbose:
                        print('enumv %s' % valstr)
                context = ''
                val += 1
        else:
            if verbose:
                print('??    %s' % lines[lno - 1])

        if start_brace > 0 and start_brace == end_brace:
            return [{'file': filename[11:], 'name': name, 'values': values}, lno]

    if len(name) > 0:
        print('\x1b[31mFAILED TO PARSE ENUM\x1b[0m %s\nline: %d\nfile: %s' % (name, lno, filename))
    return [None, lno]


def consume_block(lno, lines):
    start_brace = 0
    end_brace = 0

    while lno < len(lines):
        line = lines[lno].strip()
        if verbose:
            print('xx    %s' % line)
        lno += 1

        start_brace += line.count('{')
        end_brace += line.count('}')

        if start_brace > 0 and start_brace == end_brace:
            break
    return lno


def consume_comment(lno, lines):
    while lno < len(lines):
        line = lines[lno].strip()
        if verbose:
            print('xx    %s' % line)
        lno += 1
        if '*/' in line:
            break

    return lno


def trim_define(line):
    return line.replace('#ifndef', '').replace('#ifdef', '') \
            .replace('#if', '').replace('defined', '') \
            .replace('TORRENT_USE_IPV6', '').replace('TORRENT_ABI_VERSION == 1', '') \
            .replace('||', '').replace('&&', '').replace('(', '').replace(')', '') \
            .replace('!', '').replace('\\', '').strip()


def consume_ifdef(lno, lines, warn_on_ifdefs=False):
    line = lines[lno].strip()
    lno += 1

    start_if = 1
    end_if = 0

    if verbose:
        print('prep  %s' % line)

    if warn_on_ifdefs and line.strip().startswith('#if'):
        while line.endswith('\\'):
            lno += 1
            line += lines[lno].strip()
            if verbose:
                print('prep  %s' % lines[lno].trim())
        define = trim_define(line)
        if 'TORRENT_' in define and 'TORRENT_ABI_VERSION' not in define:
            print('\x1b[31mWARNING: possible ABI breakage in public struct! "%s" \x1b[34m %s:%d\x1b[0m' %
                  (define, filename, lno))
            # we've already warned once, no need to do it twice
            warn_on_ifdefs = False
        elif define != '':
            print('\x1b[33msensitive define in public struct: "%s"\x1b[34m %s:%d\x1b[0m' % (define, filename, lno))

    if (line.startswith('#if') and (
            ' TORRENT_USE_ASSERTS' in line or
            ' TORRENT_USE_INVARIANT_CHECKS' in line or
            ' TORRENT_ASIO_DEBUGGING' in line) or
            line == '#if TORRENT_ABI_VERSION == 1'):
        while lno < len(lines):
            line = lines[lno].strip()
            lno += 1
            if verbose:
                print('prep  %s' % line)
            if line.startswith('#endif'):
                end_if += 1
            if line.startswith('#if'):
                start_if += 1
            if line == '#else' and start_if - end_if == 1:
                break
            if start_if - end_if == 0:
                break
        return lno
    else:
        while line.endswith('\\') and lno < len(lines):
            line = lines[lno].strip()
            lno += 1
            if verbose:
                print('prep  %s' % line)

    return lno


for filename in files:
    h = open(filename)
    lines = h.read().split('\n')

    if verbose:
        print('\n=== %s ===\n' % filename)

    blanks = 0
    lno = 0
    while lno < len(lines):
        line = lines[lno].strip()
        lno += 1

        if line == '':
            blanks += 1
            context = ''
            continue

        if line.startswith('//') and line[2:].strip() == 'OVERVIEW':
            # this is a section overview
            current_overview = ''
            while lno < len(lines):
                line = lines[lno].strip()
                lno += 1
                if not line.startswith('//'):
                    # end of overview
                    overviews[filename[11:]] = current_overview
                    current_overview = ''
                    break
                line = line[2:]
                if line.startswith(' '):
                    line = line[1:]
                current_overview += line + '\n'

        if line.startswith('//'):
            if verbose:
                print('desc  %s' % line)
            line = line[2:]
            if len(line) and line[0] == ' ':
                line = line[1:]
            context += line + '\n'
            continue

        if line.startswith('/*'):
            lno = consume_comment(lno - 1, lines)
            continue

        if line.startswith('#'):
            lno = consume_ifdef(lno - 1, lines)
            continue

        if (line == 'namespace detail' or
                line == 'namespace impl' or
                line == 'namespace aux') \
                and not internal:
            lno = consume_block(lno, lines)
            continue

        if 'TORRENT_DEPRECATED' in line:
            if ('class ' in line or 'struct ' in line) and ';' not in line:
                lno = consume_block(lno - 1, lines)
                context = ''
            blanks += 1
            if verbose:
                print('xx    %s' % line)
            continue

        if 'TORRENT_EXPORT ' in line or line.startswith('inline ') or line.startswith('template') or internal:
            if line.startswith('class ') or line.startswith('struct '):
                if not line.endswith(';'):
                    current_class, lno = parse_class(lno - 1, lines, filename)
                    if current_class is not None and is_visible(context):
                        current_class['desc'] = context
                        if context == '':
                            print('WARNING: class "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                                  % (current_class['name'], filename, lno))
                        classes.append(current_class)
                context = ''
                blanks += 1
                continue

            if looks_like_function(line):
                current_fun, lno = parse_function(lno - 1, lines, filename)
                if current_fun is not None and is_visible(context):
                    if context == '' and blanks == 0 and len(functions):
                        functions[-1]['signatures'].update(current_fun['signatures'])
                        functions[-1]['names'].update(current_fun['names'])
                    else:
                        current_fun['desc'] = context
                        if context == '':
                            print('WARNING: function "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                                  % (first_item(current_fun['names']), filename, lno))
                        functions.append(current_fun)
                    context = ''
                    blanks = 0
                continue

        if ('class ' in line or 'struct ' in line) and ';' not in line:
            lno = consume_block(lno - 1, lines)
            context = ''
            blanks += 1
            continue

        if line.startswith('enum '):
            if not is_visible(context):
                consume_block(lno - 1, lines)
            else:
                current_enum, lno = parse_enum(lno - 1, lines, filename)
                if current_enum is not None and is_visible(context):
                    current_enum['desc'] = context
                    if context == '':
                        print('WARNING: enum "%s" is not documented: \x1b[34m%s:%d\x1b[0m'
                              % (current_enum['name'], filename, lno))
                    enums.append(current_enum)
            context = ''
            blanks += 1
            continue

        blanks += 1
        if verbose:
            if looks_like_forward_decl(line) \
                    or looks_like_blank(line) \
                    or looks_like_namespace(line):
                print('--    %s' % line)
            else:
                print('??    %s' % line)

        context = ''
    h.close()

# ====================================================================
#
#                               RENDER PART
#
# ====================================================================


if dump:

    if verbose:
        print('\n===============================\n')

    for c in classes:
        print('\x1b[4m%s\x1b[0m %s\n{' % (c['type'], c['name']))
        for f in c['fun']:
            for s in f['signatures']:
                print('   %s' % s.replace('\n', '\n   '))

        if len(c['fun']) > 0 and len(c['fields']) > 0:
            print('')

        for f in c['fields']:
            for s in f['signatures']:
                print('   %s' % s)

        if len(c['fields']) > 0 and len(c['enums']) > 0:
            print('')

        for e in c['enums']:
            print('   \x1b[4menum\x1b[0m %s\n   {' % e['name'])
            for v in e['values']:
                print('      %s' % v['name'])
            print('   };')
        print('};\n')

    for f in functions:
        print('%s' % f['signature'])

    for e in enums:
        print('\x1b[4menum\x1b[0m %s\n{' % e['name'])
        for v in e['values']:
            print('   %s' % v['name'])
        print('};')

categories = {}

for c in classes:
    cat = categorize_symbol(c['name'], c['file'])
    if cat not in categories:
        categories[cat] = {'classes': [], 'functions': [], 'enums': [],
                           'filename': 'reference-%s.rst' % cat.replace(' ', '_')}

    if c['file'] in overviews:
        categories[cat]['overview'] = overviews[c['file']]

    filename = categories[cat]['filename'].replace('.rst', '.html') + '#'
    categories[cat]['classes'].append(c)
    symbols[c['name']] = filename + c['name']
    for f in c['fun']:
        for n in f['names']:
            symbols[n] = filename + n
            symbols[c['name'] + '::' + n] = filename + n

    for f in c['fields']:
        for n in f['names']:
            symbols[c['name'] + '::' + n] = filename + n

    for e in c['enums']:
        symbols[e['name']] = filename + e['name']
        symbols[c['name'] + '::' + e['name']] = filename + e['name']
        for v in e['values']:
            # symbols[v['name']] = filename + v['name']
            symbols[e['name'] + '::' + v['name']] = filename + v['name']
            symbols[c['name'] + '::' + v['name']] = filename + v['name']

for f in functions:
    cat = categorize_symbol(first_item(f['names']), f['file'])
    if cat not in categories:
        categories[cat] = {'classes': [], 'functions': [], 'enums': [],
                           'filename': 'reference-%s.rst' % cat.replace(' ', '_')}

    if f['file'] in overviews:
        categories[cat]['overview'] = overviews[f['file']]

    for n in f['names']:
        symbols[n] = categories[cat]['filename'].replace('.rst', '.html') + '#' + n
    categories[cat]['functions'].append(f)

for e in enums:
    cat = categorize_symbol(e['name'], e['file'])
    if cat not in categories:
        categories[cat] = {'classes': [], 'functions': [], 'enums': [],
                           'filename': 'reference-%s.rst' % cat.replace(' ', '_')}
    categories[cat]['enums'].append(e)
    filename = categories[cat]['filename'].replace('.rst', '.html') + '#'
    symbols[e['name']] = filename + e['name']
    for v in e['values']:
        symbols[e['name'] + '::' + v['name']] = filename + v['name']


def print_declared_in(out, o):
    out.write('Declared in "%s"\n\n' % print_link(o['file'], '../include/%s' % o['file']))
    print(dump_link_targets(), file=out)

# returns RST marked up string


def linkify_symbols(string):
    lines = string.split('\n')
    ret = []
    in_literal = False
    lno = 0
    for line in lines:
        lno += 1
        # don't touch headlines, i.e. lines whose
        # next line entirely contains one of =, - or .
        if (lno < len(lines) - 1):
            next_line = lines[lno]
        else:
            next_line = ''

        if len(next_line) > 0 and lines[lno].replace('=', ''). \
                replace('-', '').replace('.', '') == '':
            ret.append(line)
            continue

        if line.startswith('|'):
            ret.append(line)
            continue
        if in_literal and not line.startswith('\t') and not line == '':
            # print('  end literal: "%s"' % line)
            in_literal = False
        if in_literal:
            # print('  literal: "%s"' % line)
            ret.append(line)
            continue
        if line.strip() == '.. parsed-literal::' or \
                line.strip().startswith('.. code::') or \
                (not line.strip().startswith('..') and line.endswith('::')):
            # print('  start literal: "%s"' % line)
            in_literal = True
        words = line.split(' ')

        for i in range(len(words)):
            # it's important to preserve leading
            # tabs, since that's relevant for
            # rst markup

            leading = ''
            w = words[i]

            if len(w) == 0:
                continue

            while len(w) > 0 and \
                    w[0] in ['\t', ' ', '(', '[', '{']:
                leading += w[0]
                w = w[1:]

            # preserve commas and dots at the end
            w = w.strip()
            trailing = ''

            if len(w) == 0:
                continue

            while len(w) > 1 and w[-1] in ['.', ',', ')'] and w[-2:] != '()':
                trailing = w[-1] + trailing
                w = w[:-1]

            link_name = w

            # print(w)

            if len(w) == 0:
                continue

            if link_name[-1] == '_':
                link_name = link_name[:-1]

            if w in symbols:
                link_name = link_name.replace('-', ' ')
                # print('  found %s -> %s' % (w, link_name))
                words[i] = leading + print_link(link_name, symbols[w]) + trailing
        ret.append(' '.join(words))
    return '\n'.join(ret)


link_targets = []


def print_link(name, target):
    global link_targets
    link_targets.append(target)
    return "`%s`__" % name


def dump_link_targets(indent=''):
    global link_targets
    ret = '\n'
    for l in link_targets:
        ret += '%s__ %s\n' % (indent, l)
    link_targets = []
    return ret


def heading(string, c, indent=''):
    string = string.strip()
    return '\n' + indent + string + '\n' + indent + (c * len(string)) + '\n'


def render_enums(out, enums, print_declared_reference, header_level):
    for e in enums:
        print('.. raw:: html\n', file=out)
        print('\t<a name="%s"></a>' % e['name'], file=out)
        print('', file=out)
        print(heading('enum %s' % e['name'], header_level), file=out)

        print_declared_in(out, e)

        width = [len('name'), len('value'), len('description')]

        for i in range(len(e['values'])):
            e['values'][i]['desc'] = linkify_symbols(e['values'][i]['desc'])

        for v in e['values']:
            width[0] = max(width[0], len(v['name']))
            width[1] = max(width[1], len(v['val']))
            for d in v['desc'].split('\n'):
                width[2] = max(width[2], len(d))

        print('+-' + ('-' * width[0]) + '-+-' + ('-' * width[1]) + '-+-' + ('-' * width[2]) + '-+', file=out)
        print(('| ' + 'name'.ljust(width[0]) + ' | ' + 'value'.ljust(width[1]) + ' | '
               'description'.ljust(width[2]) + ' |'), file=out)
        print('+=' + ('=' * width[0]) + '=+=' + ('=' * width[1]) + '=+=' + ('=' * width[2]) + '=+', file=out)
        for v in e['values']:
            d = v['desc'].split('\n')
            if len(d) == 0:
                d = ['']
                print(('| ' + v['name'].ljust(width[0]) + ' | ' + v['val'].ljust(width[1]) + ' | '
                       + d[0].ljust(width[2]) + ' |'), file=out)
            for s in d[1:]:
                print('| ' + (' ' * width[0]) + ' | ' + (' ' * width[1]) + ' | ' + s.ljust(width[2]) + ' |', file=out)
            print('+-' + ('-' * width[0]) + '-+-' + ('-' * width[1]) + '-+-' + ('-' * width[2]) + '-+', file=out)
        print('', file=out)

        print(dump_link_targets(), file=out)


sections = \
    {
        'Core': 0,
        'Session': 0,
        'Settings': 0,

        'Bencoding': 1,
        'Bdecoding': 1,
        'Filter': 1,
        'Error Codes': 1,
        'Create Torrents': 1,

        'ed25519': 2,
        'Utility': 2,
        'Storage': 2,
        'Custom Storage': 2,
        'Plugins': 2,

        'Alerts': 3
    }


def print_toc(out, categories, s):
    for cat in categories:
        if (s != 2 and cat not in sections) or \
                (cat in sections and sections[cat] != s):
            continue

        print('\t.. rubric:: %s\n' % cat, file=out)

        if 'overview' in categories[cat]:
            print('\t| overview__', file=out)

        for c in categories[cat]['classes']:
            print('\t| ' + print_link(c['name'], symbols[c['name']]), file=out)
        for f in categories[cat]['functions']:
            for n in f['names']:
                print('\t| ' + print_link(n, symbols[n]), file=out)
        for e in categories[cat]['enums']:
            print('\t| ' + print_link(e['name'], symbols[e['name']]), file=out)
        print('', file=out)

        if 'overview' in categories[cat]:
            print('\t__ %s#overview' % categories[cat]['filename'].replace('.rst', '.html'), file=out)
        print(dump_link_targets('\t'), file=out)


out = open('reference.rst', 'w+')
out.write('''=======================
reference documentation
=======================

''')

out.write('`single-page version`__\n\n__ single-page-ref.html\n\n')

for i in range(4):

    out.write('.. container:: main-toc\n\n')
    print_toc(out, categories, i)

out.close()

for cat in categories:
    out = open(categories[cat]['filename'], 'w+')

    classes = categories[cat]['classes']
    functions = categories[cat]['functions']
    enums = categories[cat]['enums']

    out.write('''
:Author: Arvid Norberg, arvid@libtorrent.org
:Version: 1.2.0

`home`__

__ reference.html

%s

.. contents:: Table of contents
  :depth: 2
  :backlinks: none

''' % heading(cat, '='))

    if 'overview' in categories[cat]:
        out.write('%s\n' % linkify_symbols(categories[cat]['overview']))

    for c in classes:

        print('.. raw:: html\n', file=out)
        print('\t<a name="%s"></a>' % c['name'], file=out)
        print('', file=out)

        out.write('%s\n' % heading(c['name'], '-'))
        print_declared_in(out, c)
        c['desc'] = linkify_symbols(c['desc'])
        out.write('%s\n' % c['desc'])
        print(dump_link_targets(), file=out)

        print('\n.. parsed-literal::\n\t', file=out)

        block = '\n%s\n{\n' % c['decl']
        for f in c['fun']:
            for s in f['signatures']:
                block += '   %s\n' % highlight_signature(s.replace('\n', '\n   '))

        if len(c['fun']) > 0 and len(c['enums']) > 0:
            block += '\n'

        first = True
        for e in c['enums']:
            if not first:
                block += '\n'
            first = False
            block += '   enum %s\n   {\n' % e['name']
            for v in e['values']:
                block += '      %s,\n' % v['name']
            block += '   };\n'

        if len(c['fun']) + len(c['enums']) > 0 and len(c['fields']):
            block += '\n'

        for f in c['fields']:
            for s in f['signatures']:
                block += '   %s\n' % s

        block += '};'

        print(block.replace('\n', '\n\t') + '\n', file=out)

        for f in c['fun']:
            if f['desc'] == '':
                continue
            title = ''
            print('.. raw:: html\n', file=out)
            for n in f['names']:
                print('\t<a name="%s"></a>' % n, file=out)
            print('', file=out)
            for n in f['names']:
                title += '%s ' % n
            print(heading(title.strip(), '.'), file=out)

            block = '.. parsed-literal::\n\n'

            for s in f['signatures']:
                block += highlight_signature(s.replace('\n', '\n   ')) + '\n'
            print('%s\n' % block.replace('\n', '\n\t'), file=out)
            f['desc'] = linkify_symbols(f['desc'])
            print('%s' % f['desc'], file=out)

            print(dump_link_targets(), file=out)

        render_enums(out, c['enums'], False, '.')

        for f in c['fields']:
            if f['desc'] == '':
                continue

            print('.. raw:: html\n', file=out)
            for n in f['names']:
                print('\t<a name="%s"></a>' % n, file=out)
            print('', file=out)

            for n in f['names']:
                print('%s ' % n, end=' ', file=out)
            print('', file=out)
            f['desc'] = linkify_symbols(f['desc'])
            print('\t%s' % f['desc'].replace('\n', '\n\t'), file=out)

            print(dump_link_targets(), file=out)

    for f in functions:
        h = ''
        print('.. raw:: html\n', file=out)
        for n in f['names']:
            print('\t<a name="%s"></a>' % n, file=out)
        print('', file=out)
        for n in f['names']:
            h += '%s ' % n
        print(heading(h, '-'), file=out)
        print_declared_in(out, f)

        block = '.. parsed-literal::\n\n'
        for s in f['signatures']:
            block += highlight_signature(s) + '\n'

        print('%s\n' % block.replace('\n', '\n\t'), file=out)
        print(linkify_symbols(f['desc']), file=out)

        print(dump_link_targets(), file=out)

    render_enums(out, enums, True, '-')

    print(dump_link_targets(), file=out)

    for i in static_links:
        print(i, file=out)

    out.close()

# for s in symbols:
#   print(s)

for i, o in list(preprocess_rst.items()):
    f = open(i, 'r')
    out = open(o, 'w+')
    print('processing %s -> %s' % (i, o))
    link = linkify_symbols(f.read())
    print(link, end=' ', file=out)

    print(dump_link_targets(), file=out)

    out.close()
    f.close()