import os

import re

import xml.etree.ElementTree as ET

from dbtexmf.core.txtparser import texinputs_parse

class BaseOption:

    def __init__(self, config, optname):

        self.config = config

        self.optname = optname

        self._value = None

    def optvalue(self):

        return self._value

    def get(self, what, default=None):

        return None

    def options(self):

        value = self.optvalue()

        if self.optname and value:

            return ["%s=%s" % (self.optname, value)]

        else:

            return []

    def fromnode(self, xmlnode):

        self._value = xmlnode.text

    def modules(self):

        return {}

class CommandConfig:

    def __init__(self, config, type="command"):

        self.config = config

        self.type = type

        self.args = []

        self.stdin = None

        self.stdout = None

        self.shell = False

    def options(self):

        return self.args

    def modules(self):

        return {}

    def fromnode(self, xmlnode):

        self.stdin = xmlnode.get("input")

        self.stdout = xmlnode.get("output")

        self.shell = xmlnode.get("shell")

        args = (xmlnode.text or "").split()

        for arg in xmlnode:

            if arg.text: args.append(arg.text)

            args.extend((arg.tail or "").split())

        self.args = args

class TexStyle(BaseOption):

    def __init__(self, config, optname):

        BaseOption.__init__(self, config, optname)

        self.filepath = ""

    def optvalue(self):

        return self.filepath

    def fromnode(self, xmlnode):

        self.filepath = xmlnode.get("fileref") or xmlnode.get("use")

class TexPath(BaseOption):

    def __init__(self, config, optname):

        BaseOption.__init__(self, config, optname)

        self.paths = []

    def optvalue(self):

        return os.pathsep.join(self.paths)

    def fromnode(self, xmlnode):

        if not(xmlnode.text): return

        self.paths = texinputs_parse(xmlnode.text, self.config.basedir)

class FilePath(BaseOption):

    def __init__(self, config, optname):

        BaseOption.__init__(self, config, optname)

        self.filepath = ""

    def optvalue(self):

        return self.filepath

    def fromnode(self, xmlnode):

        filepath = xmlnode.get("fileref")

        if not(filepath):

            return

        if not(os.path.isabs(filepath)):

            filepath = os.path.normpath(os.path.join(self.config.basedir,

                                                     filepath))

        self.filepath = filepath

class ModuleConfig(BaseOption):

    def __init__(self, config, optname):

        BaseOption.__init__(self, config, optname)

        self.commands = []

        self.extra_args = None

        self.module_name = ""

        self.module_file = ""

    def optvalue(self):

        return self.module_name or self.module_file

    def modules(self):

        if self.module_name:

            return {self.module_name: self}

        else:

            return {}

    def fromnode(self, xmlnode):

        ns = { "x": self.config.xmlns }

        self._handle_location(xmlnode)

        xmlopts = xmlnode.find("x:options", ns)

        xmlcmds = xmlnode.find("x:command", ns)

        xmlchain = xmlnode.find("x:commandchain", ns)

        if not(xmlchain is None):

            xmlcmds = xmlchain.findall("x:command", ns)

            for cmd in xmlcmds:

                args = CommandConfig(self.config)

                args.fromnode(cmd)

                self.commands.append(args)

        elif not(xmlcmds is None):

            args = CommandConfig(self.config)

            args.fromnode(xmlcmds)

            self.commands.append(args)

        elif not(xmlopts is None):

            # FIXME

            self.extra_args = CommandConfig(self.config, type="option")

            self.extra_args.fromnode(xmlopts)

    def _handle_location(self, xmlnode):

        self.module_name = xmlnode.get("use")

        self.module_file = xmlnode.get("fileref")

        if not(self.module_name) and self.module_file:

            p = FilePath(self.config, "")

            p.fromnode(xmlnode)

            self.module_file = p.filepath

class ImageConverterConfig(ModuleConfig):

    def __init__(self, config, optname):

        ModuleConfig.__init__(self, config, optname)

    def __repr__(self):

        return self.module_name

    def fromnode(self, xmlnode):

        self.imgsrc = xmlnode.get("src")

        self.imgdst = xmlnode.get("dst")

        self.docformat = xmlnode.get("docformat") or "*"

        self.backend = xmlnode.get("backend") or "*"

        ModuleConfig.fromnode(self, xmlnode)

        name = "%s/%s/%s/%s" % (self.imgsrc, self.imgdst,

                                self.docformat, self.backend)

        self.module_name = name

class ImageFormatConfig(BaseOption):

    def __init__(self, config, optname):

        BaseOption.__init__(self, config, optname)

        self.imgsrc = ""

        self.imgdst = ""

        self.docformat = ""

        self.backend = ""

    def fromnode(self, xmlnode):

        self.imgsrc = xmlnode.get("src")

        self.imgdst = xmlnode.get("dst")

        self.docformat = xmlnode.get("docformat") or "*"

        self.backend = xmlnode.get("backend") or "*"

class XsltEngineConfig(ModuleConfig):

    def __init__(self, config, optname):

        ModuleConfig.__init__(self, config, optname)

    def __repr__(self):

        return self.module_name

    def fromnode(self, xmlnode):

        self.param_format = xmlnode.get("param-format")

        ModuleConfig.fromnode(self, xmlnode)

        if not(self.module_name or self.module_file):

            self.module_name = "xsltconf"

class XmlConfigGroup:

    node_parsers = {}

    def __init__(self, config):

        self.config = config

        self.tagname = ""

        self.infos = {}

    def get(self, tag, default=""):

        if default == "": default = BaseOption(self, "")

        return self.infos.get(tag, default)

    def _register(self, xmlnode, info):

        tag = self.strip_ns(xmlnode.tag)

        taglist = self.infos.get(tag, [])

        taglist.append(info)

        self.infos[tag] = taglist

    def strip_ns(self, tag):

        return self.config.strip_ns(tag)

    def options(self):

        opts = []

        for parsers in self.infos.values():

            for parser in parsers:

                opts.extend(parser.options())

        return opts

    def modules(self):

        mods = {}

        for parsers in self.infos.values():

            for parser in parsers:

                mods.update(parser.modules())

        return mods

    def fromnode(self, xmlnode):

        self.tagname = xmlnode.tag

        for child in xmlnode:

            found = self.node_parsers.get(self.strip_ns(child.tag))

            if found:

                optname, parser_cls = found

                parser = parser_cls(self.config, optname)

                parser.fromnode(child)

                self._register(child, parser)

class LatexConfig(XmlConfigGroup):

    node_parsers = {

        "texinputs":  ("--texinputs", TexPath),

        "bibinputs":  ("--bib-path", TexPath),

        "bstinputs":  ("--bst-path", TexPath),

        "texstyle":   ("--texstyle", TexStyle),

        "indexstyle": ("--indexstyle", FilePath),

        "backend":    ("--backend", ModuleConfig),

        "texpost":    ("--texpost", ModuleConfig)

    }

class XsltConfig(XmlConfigGroup):

    node_parsers = {

        "stylesheet": ("--xsl-user", FilePath),

        "engine":     ("--xslt", XsltEngineConfig)

    }

class ImageConfig(XmlConfigGroup):

    node_parsers = {

        "figpath": ("--fig-path", FilePath),

        "figformat": ("--fig-format", BaseOption),

        "converter": ("", ImageConverterConfig),

        "formatrule": ("", ImageFormatConfig)

    }

class XmlConfig:

    """

    Parses an XML configuration file and stores its data in

    configuration objects.

    """

    node_parsers = {

        "latex": LatexConfig,

        "xslt": XsltConfig,

        "imagedata": ImageConfig,

        "options": CommandConfig

    }

    xmlns = "http://dblatex.sourceforge.net/config"

    root_tag = "config"

    def __init__(self):

        self.basedir = ""

        self.infos = {}

    def _register(self, xmlnode, info):

        self.infos[self.strip_ns(xmlnode.tag)] = info

    def get(self, tag, default=""):

        if default == "": default = BaseOption(self, "")

        return self.infos.get(tag, default)

    def options(self):

        opts = []

        for parser in self.infos.values():

            opts.extend(parser.options())

        return opts

    def modules(self):

        mods = {}

        for parser in self.infos.values():

            mods.update(parser.modules())

        return mods

    def strip_ns(self, tag):

        return tag.replace("{%s}" % self.xmlns, "", 1)

    def fromfile(self, filename):

        self.basedir = os.path.dirname(os.path.realpath(filename))

        document = ET.parse(filename)

        root = document.getroot()

        self._check_root(root.tag)

        for child in root:

            parser_cls = self.node_parsers.get(self.strip_ns(child.tag))

            if parser_cls:

                parser = parser_cls(self)

                parser.fromnode(child)

                self._register(child, parser)

    def _check_root(self, root):

        xmlns, tag = self._split_xmlns(root)

        if tag != self.root_tag:

            raise ValueError("Expect the XML config root element being '%s'" % \

                             self.root_tag)

        if xmlns and xmlns != self.xmlns:

            raise ValueError("Invalid XML config xmlns: '%s'" % xmlns)

    def _split_xmlns(self, tag):

        m = re.match("{([^}]+)}(.*)", tag)

        if m:

            return m.group(1), m.group(2)

        else:

            return "", tag