#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
import jinja2
import optparse
import os
import sys
import importlib

BASEPATH = os.path.abspath(os.path.join(os.path.dirname(__file__)))
sys.path.insert(0, BASEPATH)


class rspec(dict):
    KEY_MAIN_TITLE = "title"
    KEY_MAIN_ENTRIES = "entries"
    KEY_MAIN_SECTIONS = "sections"

    KEY_SEC_CHILDS = "childs"

    def __init__(self):
        super().__init__()
        self[self.KEY_MAIN_ENTRIES] = {}
        self[self.KEY_MAIN_SECTIONS] = []

    def add_title(self, title):
        self[self.KEY_MAIN_TITLE] = title

    def add(self, **kwargs):
        #
        # UUID
        #
        try:
            uuid = kwargs.pop("itemtype") + "-" + "%04d" % kwargs.pop("id")
        except KeyError:
            raise KeyError(
                "Missing required argument itemtype or id in kwargs: %s" % repr(kwargs))
        #
        # Check uuid is unique
        #
        if uuid in self[self.KEY_MAIN_ENTRIES]:
            raise AttributeError("UUID %s already exists in entries" % uuid)
        #
        # Parent
        #
        try:
            parent = kwargs.pop("parent")
        except KeyError:
            if not uuid.lower().startswith("sec"):
                raise KeyError(
                    "You need to specify a parent for non sec entries")
        #
        # Create Structure
        #
        if uuid.lower().startswith("sec"):
            # Create section
            self[self.KEY_MAIN_SECTIONS].append(uuid)
        else:
            # Add item to section
            self[self.KEY_MAIN_ENTRIES][parent][self.KEY_SEC_CHILDS].append(uuid)

        #
        # Add item to itemlist
        #
        if uuid.lower().startswith("sec"):
            kwargs[self.KEY_SEC_CHILDS] = []
        self[self.KEY_MAIN_ENTRIES][uuid] = kwargs
        #
        return uuid


def rs_by_spec_file(spec_file):
    spec = importlib.util.spec_from_file_location("specification", spec_file)
    s = importlib.util.module_from_spec(spec)
    sys.modules["specification"] = s
    spec.loader.exec_module(s)
    #
    rs = rspec()
    s.specification(rs)
    return rs


if __name__ == '__main__':
    parser = optparse.OptionParser("usage: %prog reqif_file")
    parser.add_option("-t", "--template", dest="template", default=os.path.join(BASEPATH,
                      'templates', 'tex', 'requirement_specification.tex'), help="path to the template")
    (options, args) = parser.parse_args()

    #
    # Check options and args
    if len(args) != 1 or not os.path.isfile(args[0]):
        parser.print_help()
    else:
        rs = rs_by_spec_file(args[0])
        #
        template_path = os.path.abspath(options.template)
        jenv = jinja2.Environment(
            loader=jinja2.FileSystemLoader(os.path.dirname(template_path)))
        template = jenv.get_template(os.path.basename(template_path))
        print(template.render(data=rs))