# templater.py - template expansion for output

#

# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>

#

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

# of the GNU General Public License, incorporated herein by reference.

import re

from demandload import demandload

from i18n import gettext as _

demandload(globals(), "cStringIO cgi os time urllib util")

esctable = {

    '\\': '\\',

    'r': '\r',

    't': '\t',

    'n': '\n',

    'v': '\v',

    }

def parsestring(s, quoted=True):

    '''parse a string using simple c-like syntax.

    string must be in quotes if quoted is True.'''

    fp = cStringIO.StringIO()

    if quoted:

        first = s[0]

        if len(s) < 2: raise SyntaxError(_('string too short'))

        if first not in "'\"": raise SyntaxError(_('invalid quote'))

        if s[-1] != first: raise SyntaxError(_('unmatched quotes'))

        s = s[1:-1]

    escape = False

    for c in s:

        if escape:

            fp.write(esctable.get(c, c))

            escape = False

        elif c == '\\': escape = True

        elif quoted and c == first: raise SyntaxError(_('string ends early'))

        else: fp.write(c)

    if escape: raise SyntaxError(_('unterminated escape'))

    return fp.getvalue()

class templater(object):

    '''template expansion engine.

    template expansion works like this. a map file contains key=value

    pairs. if value is quoted, it is treated as string. otherwise, it

    is treated as name of template file.

    templater is asked to expand a key in map. it looks up key, and

    looks for atrings like this: {foo}. it expands {foo} by looking up

    foo in map, and substituting it. expansion is recursive: it stops

    when there is no more {foo} to replace.

    expansion also allows formatting and filtering.

    format uses key to expand each item in list. syntax is

    {key%format}.

    filter uses function to transform value. syntax is

    {key|filter1|filter2|...}.'''

    def __init__(self, mapfile, filters={}, cache={}):

        '''set up template engine.

        mapfile is name of file to read map definitions from.

        filters is dict of functions. each transforms a value into another.

        defaults is dict of default map definitions.'''

        self.mapfile = mapfile or 'template'

        self.cache = {}

        self.map = {}

        self.base = (mapfile and os.path.dirname(mapfile)) or ''

        self.filters = filters

        self.defaults = {}

        self.cache = cache

        if not mapfile:

            return

        i = 0

        for l in file(mapfile):

            l = l.strip()

            i += 1

            if not l or l[0] in '#;': continue

            m = re.match(r'([a-zA-Z_][a-zA-Z0-9_]*)\s*=\s*(.+)$', l)

            if m:

                key, val = m.groups()

                if val[0] in "'\"":

                    try:

                        self.cache[key] = parsestring(val)

                    except SyntaxError, inst:

                        raise SyntaxError('%s:%s: %s' %

                                          (mapfile, i, inst.args[0]))

                else:

                    self.map[key] = os.path.join(self.base, val)

            else:

                raise SyntaxError(_("%s:%s: parse error") % (mapfile, i))

    def __contains__(self, key):

        return key in self.cache

    def __call__(self, t, **map):

        '''perform expansion.

        t is name of map element to expand.

        map is added elements to use during expansion.'''

        m = self.defaults.copy()

        m.update(map)

        try:

            tmpl = self.cache[t]

        except KeyError:

            try:

                tmpl = self.cache[t] = file(self.map[t]).read()

            except IOError, inst:

                raise IOError(inst.args[0], _('template file %s: %s') %

                              (self.map[t], inst.args[1]))

        return self.template(tmpl, self.filters, **m)

    template_re = re.compile(r"[#{]([a-zA-Z_][a-zA-Z0-9_]*)"

                             r"((%[a-zA-Z_][a-zA-Z0-9_]*)*)"

                             r"((\|[a-zA-Z_][a-zA-Z0-9_]*)*)[#}]")

    def template(self, tmpl, filters={}, **map):

        lm = map.copy()

        while tmpl:

            m = self.template_re.search(tmpl)

            if m:

                start, end = m.span(0)

                s, e = tmpl[start], tmpl[end - 1]

                key = m.group(1)

                if ((s == '#' and e != '#') or (s == '{' and e != '}')):

                    raise SyntaxError(_("'%s'/'%s' mismatch expanding '%s'") %

                                      (s, e, key))

                if start:

                    yield tmpl[:start]

                v = map.get(key, "")

                v = callable(v) and v(**map) or v

                format = m.group(2)

                fl = m.group(4)

                if format:

                    q = v.__iter__

                    for i in q():

                        lm.update(i)

                        yield self(format[1:], **lm)

                    v = ""

                elif fl:

                    for f in fl.split("|")[1:]:

                        v = filters[f](v)

                yield v

                tmpl = tmpl[end:]

            else:

                yield tmpl

                break

agescales = [("second", 1),

             ("minute", 60),

             ("hour", 3600),

             ("day", 3600 * 24),

             ("week", 3600 * 24 * 7),

             ("month", 3600 * 24 * 30),

             ("year", 3600 * 24 * 365)]

agescales.reverse()

def age(date):

    '''turn a (timestamp, tzoff) tuple into an age string.'''

    def plural(t, c):

        if c == 1:

            return t

        return t + "s"

    def fmt(t, c):

        return "%d %s" % (c, plural(t, c))

    now = time.time()

    then = date[0]

    delta = max(1, int(now - then))

    for t, s in agescales:

        n = delta / s

        if n >= 2 or s == 1:

            return fmt(t, n)

def isodate(date):

    '''turn a (timestamp, tzoff) tuple into an iso 8631 date.'''

    return util.datestr(date, format='%Y-%m-%d %H:%M')

def nl2br(text):

    '''replace raw newlines with xhtml line breaks.'''

    return text.replace('\n', '<br/>\n')

def obfuscate(text):

    return ''.join(['&#%d;' % ord(c) for c in text])

def domain(author):

    '''get domain of author, or empty string if none.'''

    f = author.find('@')

    if f == -1: return ''

    author = author[f+1:]

    f = author.find('>')

    if f >= 0: author = author[:f]

    return author

def person(author):

    '''get name of author, or else username.'''

    f = author.find('<')

    if f == -1: return util.shortuser(author)

    return author[:f].rstrip()

common_filters = {

    "addbreaks": nl2br,

    "age": age,

    "date": lambda x: util.datestr(x),

    "domain": domain,

    "escape": lambda x: cgi.escape(x, True),

    "firstline": lambda x: x.splitlines(1)[0].rstrip('\r\n'),

    "isodate": isodate,

    "obfuscate": obfuscate,

    "permissions": lambda x: x and "-rwxr-xr-x" or "-rw-r--r--",

    "person": person,

    "rfc822date": lambda x: util.datestr(x, "%a, %d %b %Y %H:%M:%S"),

    "short": lambda x: x[:12],

    "strip": lambda x: x.strip(),

    "urlescape": lambda x: urllib.quote(x),

    "user": lambda x: util.shortuser(x),

    }

def templatepath(name=None):

    '''return location of template file or directory (if no name).

    returns None if not found.'''

    for f in 'templates', '../templates':

        fl = f.split('/')

        if name: fl.append(name)

        p = os.path.join(os.path.dirname(__file__), *fl)

        if (name and os.path.exists(p)) or os.path.isdir(p):

            return os.path.normpath(p)