# Copyright (c) 2005 Eric Mangold
# See LICENSE for details.

"""
This module implements a zsh code generator which generates completion code for
commands that use twisted.python.usage. This is the stuff that makes pressing
Tab at the command line work.

API Stability: API? what API?

@maintainer: U{Eric Mangold<mailto:teratorn@twistedmatrix.com>}

To build completion functions for your own commands, and not Twisted commands,
then just do something like this::

    o = mymodule.MyOptions()
    f = file('_mycommand', 'w')
    Builder(\"mycommand\", o, f).write()

Then all you have to do is place the generated file somewhere in your
C{$fpath}, and restart zsh. Note the \"site-functions\" directory in your
C{$fpath} where you may install 3rd-party completion functions (like the one
you're building). Use the C{siteFunctionsPath} function below to locate this
directory programmatically.

SPECIAL CLASS VARIABLES. You may set these on your usage.Options subclass::

    zsh_altArgDescr
    zsh_multiUse
    zsh_mutuallyExclusive
    zsh_actions
    zsh_actionDescr
    zsh_extras

Here is what they mean (with examples)::

    zsh_altArgDescr = {\"foo\":\"use this description for foo instead\"}
        A dict mapping long option names to alternate descriptions.  When this
        variable is present, the descriptions contained here will override
        those descriptions provided in the optFlags and optParameters
        variables.

    zsh_multiUse = [\"foo\", \"bar\"]
        A sequence containing those long option names which may appear on the
        command line more than once. By default, options will only be completed
        one time.

    zsh_mutuallyExclusive = [(\"foo\", \"bar\"), (\"bar\", \"baz\")]
        A sequence of sequences, with each sub-sequence containing those long
        option names that are mutually exclusive. That is, those options that
        cannot appear on the command line together.

    zsh_actions = {\"foo\":'_files -g \"*.foo\"', \"bar\":\"(one two three)\",
            \"colors\":\"_values -s , 'colors to use' red green blue\"}
        A dict mapping long option names to Zsh \"actions\". These actions
        define what will be completed as the argument to the given option.  By
        default, all files/dirs will be completed if no action is given.

        As you can see in the example above. The \"foo\" option will have files
        that end in .foo completed when the user presses Tab. The \"bar\"
        option will have either of the strings \"one\", \"two\", or \"three\"
        compelted when the user presses Tab.

        \"colors\" will allow multiple arguments to be completed, seperated by
        commas. The possible arguments are red, green, and blue. Examples::

            my_command --foo some-file.foo --colors=red,green
            my_command --colors=green
            my_command --colors=green,blue

        Actions may take many forms, and it is beyond the scope of this
        document to illustrate them all. Please refer to the documention for
        the Zsh _arguments function. zshcomp is basically a front-end to Zsh's
        _arguments completion function.

        That documentation is available on the zsh web site at this URL:
        U{http://zsh.sunsite.dk/Doc/Release/zsh_19.html#SEC124}

    zsh_actionDescr = {\"logfile\":\"log file name\", \"random\":\"random seed\"}
        A dict mapping long option names to a description for the corresponding
        zsh \"action\". These descriptions are show above the generated matches
        when the user is doing completions for this option.

        Normally Zsh does not show these descriptions unless you have
        \"verbose\" completion turned on. Turn on verbosity with this in your
        ~/.zshrc::

            zstyle ':completion:*' verbose yes
            zstyle ':completion:*:descriptions' format '%B%d%b'

    zsh_extras = [\":file to read from:action\", \":file to write to:action\"]
        A sequence of extra arguments that will be passed verbatim to Zsh's
        _arguments completion function. The _arguments function does all the
        hard work of doing command line completions. You can see how zshcomp
        invokes the _arguments call by looking at the generated completion
        files that this module creates.

   *** NOTE ***

        You will need to use this variable to describe completions for normal
        command line arguments. That is, those arguments that are not
        associated with an option. That is, the arguments that are given to the
        parseArgs method of your usage.Options subclass.

        In the example above, the 1st non-option argument will be described as
        \"file to read from\" and completion options will be generated in
        accordance with the \"action\". (See above about zsh \"actions\") The
        2nd non-option argument will be described as \"file to write to\" and
        the action will be interpreted likewise.

        Things you can put here are all documented under the _arguments
        function here: U{http://zsh.sunsite.dk/Doc/Release/zsh_19.html#SEC124}

Zsh Notes:

To enable advanced completion add something like this to your ~/.zshrc::

    autoload -U compinit
    compinit

For some extra verbosity, and general niceness add these lines too::

    zstyle ':completion:*' verbose yes
    zstyle ':completion:*:descriptions' format '%B%d%b'
    zstyle ':completion:*:messages' format '%d'
    zstyle ':completion:*:warnings' format 'No matches for: %d'

Have fun!
"""
import itertools
import sys, commands
import os.path
from twisted.python import reflect, util, usage


class MyOptions(usage.Options):
    longdesc = ""
    synopsis = "Usage: python zshcomp.py [--install | -i] | <output directory>"
    optFlags = [["install", "i", "Output files to the \"installation\" directory " \
               "(twisted/python/zsh in the currently active Twisted package)"]]
    optParameters = [["directory", "d", None, "Output files to this directory"]]
    def postOptions(self):
        if self['install'] and self['directory']:
            raise usage.UsageError, "Can't have --install and --directory at the same time"
        if not self['install'] and not self['directory']:
            raise usage.UsageError, "Not enough arguments"
        if self['directory'] and not os.path.isdir(self['directory']):
            raise usage.UsageError, "%s is not a directory" % self['directory']

class Builder:
    def __init__(self, cmd_name, options, file):
        self.cmd_name = cmd_name
        self.options = options
        self.file = file

    def write(self):
        #by default, we just write out a single call to _arguments
        self.file.write('#compdef %s\n' % self.cmd_name)
        gen = ArgumentsGenerator(self.cmd_name, self.options, self.file)
        gen.write()

class MktapBuilder(Builder):
    def write(self):
        self.file.write('#compdef mktap\n')
        self.file.write('_mktap_subcmds=(\n')
        from twisted import plugin as newplugin
        from twisted.scripts.mktap import IServiceMaker
        plugins = newplugin.getPlugins(IServiceMaker)

        for p in plugins:
            self.file.write('"%s:%s"\n' % (p.tapname, p.description))
        self.file.write(")\n\n")

        self.options.__class__.zsh_extras = ['*::subcmd:->subcmd']
        gen = ArgumentsGenerator(self.cmd_name, self.options, self.file)
        gen.write()

        self.file.write("""if (( CURRENT == 1 )); then
  _describe "tap to build" _mktap_subcmds && ret=0
fi
(( ret )) || return 0

service="$words[1]"

case $service in\n""")

        plugins = newplugin.getPlugins(IServiceMaker)
        for p in plugins:
            self.file.write(p.tapname + ")\n")
            gen = ArgumentsGenerator(p.tapname, p.options(), self.file)
            gen.write()
            self.file.write(";;\n")
        self.file.write("""*) _message "don't know how to complete $service";;\nesac""")

class ArgumentsGenerator:
    """generate a call to the zsh _arguments completion function
    based on data in a usage.Options subclass"""
    def __init__(self, cmd_name, options, file):
        """write the zsh completion code to the given file"""
        self.cmd_name = cmd_name
        self.options = options
        self.file = file

        self.altArgDescr = {}
        self.actionDescr = {}
        self.multiUse = []
        self.mutuallyExclusive = []
        self.actions = {}
        self.extras = []

        aCL = reflect.accumulateClassList
        aCD = reflect.accumulateClassDict

        aCD(options.__class__, 'zsh_altArgDescr', self.altArgDescr)
        aCD(options.__class__, 'zsh_actionDescr', self.actionDescr)
        aCL(options.__class__, 'zsh_multiUse', self.multiUse)
        aCL(options.__class__, 'zsh_mutuallyExclusive', self.mutuallyExclusive)
        aCD(options.__class__, 'zsh_actions', self.actions)
        aCL(options.__class__, 'zsh_extras', self.extras)

        optFlags = []
        optParams = []

        aCL(options.__class__, 'optFlags', optFlags)
#        optFlags = getattr(options, 'optFlags', [])
        aCL(options.__class__, 'optParameters', optParams)
#        optParams = getattr(options, 'optParameters', [])

#        for l in optFlags:
#            print l
#        for l in optParams:
#            print l

        for i, optList in enumerate(optFlags):
            if len(optList) != 3:
                optFlags[i] = util.padTo(3, optList)

        for i, optList in enumerate(optParams):
            if len(optList) != 4:
                optParams[i] = util.padTo(4, optList)


        self.optFlags = optFlags
        self.optParams = optParams

        optParams_d = {}
        for optList in optParams:
            optParams_d[optList[0]] = optList[1:]
        self.optParams_d = optParams_d

        optFlags_d = {}
        for optList in optFlags:
            optFlags_d[optList[0]] = optList[1:]
        self.optFlags_d = optFlags_d

        optAll_d = {}
        optAll_d.update(optParams_d)
        optAll_d.update(optFlags_d)
        self.optAll_d = optAll_d

        self.addAdditionalOptions()

        # makes sure none of the zsh_ data structures reference option names that
        # don't exist. (great for catching typos)
        self.verifyZshNames()
        
        self.excludes = self.makeExcludesDict()

    def write(self):
        self.writeHeader()
        self.writeExtras()
        self.writeOptions()
        self.writeFooter()

    def writeHeader(self):
        self.file.write('_arguments -s -A "-*" \\\n')

    def writeOptions(self):
        for long in self.optAll_d:
            self.writeOption(long)

    def writeExtras(self):
        for s in self.extras:
            self.file.write(escape(s))
            self.file.write(' \\\n')

    def writeFooter(self):
        self.file.write('&& return 0\n')

    def verifyZshNames(self):
        def err(name):
            raise ValueError, "Unknown option name \"%s\" found while\n" \
                "examining zsh_ attributes for the %s command" % (
                    name, self.cmd_name)

        for name in itertools.chain(self.altArgDescr, self.actionDescr, self.actions,
                                                             self.multiUse):
            if name not in self.optAll_d:
                err(name)

        for seq in self.mutuallyExclusive:
            for name in seq:
                if name not in self.optAll_d:
                    err(name)

    def excludeStr(self, long, buildShort=False):
        """buildShort may be True to indicate we're building an excludes
        string for the short option that correspondes to the given long opt"""
        if long in self.excludes:
            exclusions = self.excludes[long][:]
        else:
            exclusions = []

        # if we aren't a multiUse option (can't appear on the cmd line more
        # than once), then we have to exclude the short option if we're
        # building for the long option, and vice versa.
        if long not in self.multiUse:
            if buildShort is False:
                short = self.getShortOption(long)
                if short is not None:
                    exclusions.append(short)
            else:
                exclusions.append(long)

        if not exclusions:
            return ''

        strings = []
        for optName in exclusions:
            if len(optName) == 1:
                # short option
                strings.append("-" + optName)
            else:
                strings.append("--" + optName)
        return "(%s)" % " ".join(strings)

    def makeExcludesDict(self):
        """return a dict that maps each option name appearing in
        self.mutuallyExclusive to a list of those option names that
        is it mutually exclusive with (can't appear on the cmd line with)"""

        #create a mapping of long option name -> single character name
        longToShort = {}
        for optList in itertools.chain(self.optParams, self.optFlags):
            try:
                if optList[1] != None:
                    longToShort[optList[0]] = optList[1]
            except IndexError:
                pass

        excludes = {}
        for lst in self.mutuallyExclusive:
            for i, long in enumerate(lst):
                tmp = []
                tmp.extend(lst[:i])
                tmp.extend(lst[i+1:])
                for name in tmp[:]:
                    if name in longToShort:
                        tmp.append(longToShort[name])

                if long in excludes:
                    excludes[long].extend(tmp)
                else:
                    excludes[long] = tmp
        return excludes

    def writeOption(self, long):
        if long in self.optFlags_d: # It's a flag option. Not one that takes a parameter.
            long_field = "--%s" % long
        else:
            long_field = "--%s=" % long

        short = self.getShortOption(long)
        if short != None:
            short_field = "-" + short
        else:
            short_field = ''
        
        descr = self.getDescription(long)
        descr_field = descr.replace("[", "\[")
        descr_field = descr_field.replace("]", "\]")
        descr_field = '[%s]' % descr_field

        if long in self.actionDescr:
            actionDescr_field = self.actionDescr[long]
        else:
            actionDescr_field = descr

        #longExclude_field, shortExclude_field = self.makeExcludeStrings(long, short)
        action_field = self.getAction(long)
        if long in self.multiUse:
            multi_field = '*'
        else:
            multi_field = ''

        longExclusions_field = self.excludeStr(long)

        if short:
            #we have to write an extra line for the short option if we have one
            shortExclusions_field = self.excludeStr(long, buildShort=True)
            self.file.write(escape('%s%s%s%s%s' %
                (shortExclusions_field, multi_field, short_field, descr_field, action_field)))
            self.file.write(' \\\n')

        self.file.write(escape('%s%s%s%s%s' %
            (longExclusions_field, multi_field, long_field, descr_field, action_field)))
        self.file.write(' \\\n')

    def getAction(self, long):
        if long in self.actions:
            return ":%s:%s" % (self.getActionDescr(long), self.actions[long])
        if long in self.optParams_d:
            return ':%s:_files' % self.getActionDescr(long)
        return ''

    def getActionDescr(self, long):
        if long in self.actionDescr:
            return self.actionDescr[long]
        else:
            return long

    def getDescription(self, long):
        """Return the description to be used for this long argument"""
        #check if we have an alternate descr for this arg, and if so use it
        if long in self.altArgDescr:
            return self.altArgDescr[long]

        #otherwise we have to get it from the optFlags or optParams
        try:
            descr = self.optFlags_d[long][1]
        except KeyError:
            try:
                descr = self.optParams_d[long][2]
            except KeyError:
                descr = None

        if descr is not None:
            return descr

        # lets try to get it from the opt_foo method doc string, if there is one
        longMangled = long.replace('-', '_') # this is what t.p.usage does
        obj = getattr(self.options, 'opt_%s' % longMangled, None)
        if obj:
            descr = descrFromDoc(obj)
            if descr is not None:
                return descr

        return long # we really ought to have a good description to use

    def getShortOption(self, long):
        """Return the short option letter or None"""
        optList = self.optAll_d[long]
        try:
            return optList[0] or None
        except IndexError:
            pass

    def addAdditionalOptions(self):
        """Add additional options to the optFlags and optParams lists.
        These will be defined by 'opt_foo' methods of the Options subclass"""
        methodsDict = {}
        reflect.accumulateMethods(self.options, methodsDict, 'opt_')
        # we need to go through methodsDict and figure out is there are such things as
        # opt_debug and opt_b that point to the same method (long and short option names
        methodToShort = {}
        for name in methodsDict.copy():
            if len(name) == 1:
                methodToShort[methodsDict[name]] = name
                del methodsDict[name]

        for methodName, methodObj in methodsDict.items():
            long = methodName.replace('_', '-') # t.p.usage does this
            # if this option is already defined by the optFlags or
            # optParameters then we don't want to override that data
            if long in self.optAll_d:
                continue

            descr = self.getDescription(long)

            short = None
            if methodObj in methodToShort:
                short = methodToShort[methodObj]

            reqArgs = methodObj.im_func.func_code.co_argcount
            if reqArgs == 2:
                self.optParams.append([long, short, None, descr])
                self.optParams_d[long] = [short, None, descr]
                self.optAll_d[long] = [short, None, descr]
            elif reqArgs == 1:
                self.optFlags.append([long, short, descr])
                self.optFlags_d[long] = [short, descr]
                self.optAll_d[long] = [short, None, descr]
            else:
                raise SystemExit, 'opt_ method has wrong number of arguments'

def descrFromDoc(obj):
    if obj.__doc__ is None:
        return None

    lines = obj.__doc__.split("\n")
    descr = None
    try:
        if lines[0] != "" and not lines[0].isspace():
            descr = lines[0].lstrip()
        # skip first line if it's blank
        elif lines[1] != "" and not lines[1].isspace():
            descr = lines[1].lstrip()
    except IndexError:
        pass
    return descr

def firstLine(s):
    try:
        i = s.index('\n')
        return s[:i]
    except ValueError:
        return s

def escape(str):
    return commands.mkarg(str)[1:]

def siteFunctionsPath():
    try:
        output = commands.getoutput("zsh -f -c 'echo ${(M)fpath:#/*/site-functions}'")
        if os.path.isdir(output):
            return output
    except:
        pass

def makeCompFunctionFiles(out_path):
    for cmd_name, module_name, class_name in generateFor:
        m = __import__('%s' % module_name, None, None, (class_name))
        o = getattr(m, class_name)() # instantiate Options class
        f = file('%s/_%s' % (out_path, cmd_name), 'w')

        if cmd_name in specialBuilders:
            b = specialBuilders[cmd_name](cmd_name, o, f)
            b.write()
        else:
            b = Builder(cmd_name, o, f)
            b.write()

def run():
    options = MyOptions()
    try:
        options.parseOptions(sys.argv[1:])
    except usage.UsageError, e:
        print e
        print options.getUsage()
        sys.exit(2)

    if options['install']:
        import twisted
        dir = os.path.dirname(twisted.__file__) + os.path.sep + os.path.join("python", "zsh")
        makeCompFunctionFiles(dir)
    else:
        makeCompFunctionFiles(options['directory'])

generateFor = [
               ('conch', 'twisted.conch.scripts.conch', 'ClientOptions'),
               ('mktap', 'twisted.scripts.mktap', 'FirstPassOptions'),
               ('trial', 'twisted.scripts.trial', 'Options'),
               ('cftp', 'twisted.conch.scripts.cftp', 'ClientOptions'),
               ('tapconvert', 'twisted.scripts.tapconvert', 'ConvertOptions'),
               ('twistd', 'twisted.scripts.twistd', 'ServerOptions'),
               ('ckeygen', 'twisted.conch.scripts.ckeygen', 'GeneralOptions'),
               ('lore', 'twisted.lore.scripts.lore', 'Options'),
               ('pyhtmlizer', 'twisted.scripts.htmlizer', 'Options'),
               ('websetroot', 'twisted.web.scripts.websetroot', 'Options'),
               ('tap2deb', 'twisted.scripts.tap2deb', 'MyOptions'),
               ('tkmktap', 'twisted.scripts.tap2deb', 'MyOptions'),
               ('tkconch', 'twisted.conch.scripts.tkconch', 'GeneralOptions'),
               ('manhole', 'twisted.scripts.manhole', 'MyOptions'),
               ('tap2rpm', 'twisted.scripts.tap2rpm', 'MyOptions'),
               ]

specialBuilders = {'mktap' : MktapBuilder}

if __name__ == '__main__':
    run()
