#
# S. Van Hoey
#
# Build script for tdwg dwc handling
#

import io
import csv
import sys

from urllib import request

from Cheetah.Template import Template


class ProvidedTermsError(Exception):
    """Inconsistency in the available terms Error"""
    pass

class RdfTypeError(Exception):
    """Rdftype encountered that is not known by builder"""
    pass


class DwcBuildReader():

    def __init__(self, dwc_build_file):
        """Custom Reader switching between to raw Github or local file"""
        self.dwc_build_file = dwc_build_file

    def __enter__(self):
        if "https://raw.github" in self.dwc_build_file:
            self.open_dwc_term = request.urlopen(self.dwc_build_file)
        else:
            self.open_dwc_term = open(self.dwc_build_file, 'rb')
        return self.open_dwc_term

    def __exit__(self, *args):
        self.open_dwc_term.close()


class DwcDigester(object):

    def __init__(self, term_versions, terms_config):
        self.term_versions = term_versions
        self.terms_config = terms_config

        self.term_versions_data = {}
        self._store_versions()
        self.terms_config_data = {}
        self._store_config()

        # check for the ability to combine the data
        self.match_error_report()

    def versions(self):
        """iterator to provide the terms as represented in the term versions file"""
        with DwcBuildReader(self.term_versions) as versions:
            for vterm in csv.DictReader(io.TextIOWrapper(versions), delimiter=','):
                if vterm["status"] == "recommended":
                    yield vterm

    def config(self):
        """iterator to provide the terms as represented in the terms config file
        (including the sequence)"""
        with DwcBuildReader(self.terms_config) as configs:
            for cfterm in csv.DictReader(io.TextIOWrapper(configs), delimiter=','):
                yield cfterm

    def _store_versions(self):
        """collect all the versions data in a dictionary"""
        for term in self.versions():
            self.term_versions_data[term["term_iri"]] = term

    def _store_config(self):
        """collect all the config data in a dictionary"""
        for term in self.config():
            self.terms_config_data[term["term_iri"]] = term

    def _version_terms(self):
        """get an overview of the terms in the term_versions file"""
        return set(self.term_versions_data.keys())

    def _config_terms(self):
        """get an overview of the terms in the terms config file"""
        return set(self.terms_config_data.keys())

    def _select_versions_term(self, term_iri):
        """Select a specific term of the versions data, using term_iri match"""
        return self.term_versions_data[term_iri]

    def _select_config_term(self, term_iri):
        """Select a specific term of the config data, using term_iri match"""
        return self.terms_config_data[term_iri]

    def match_error_report(self):
        """check if the prime dwc file and the humaninfo file provide corresponding terms"""
        overload_versionterms = self._version_terms() - self._config_terms()
        overload_configterms = self._config_terms() - self._version_terms()
        if len(overload_versionterms) > 0 or len(overload_configterms) > 0:
            vs_terms = ", ".join([term.split("/")[-1] for term in overload_versionterms])
            cf_terms = ", ".join([term.split("/")[-1] for term in overload_configterms])
            raise ProvidedTermsError("".join(["Terms only in term_versions.csv: ", vs_terms,
                                              ". Terms only in terms_config.csv: ", cf_terms]))

    def get_term_definition(self, term):
        """Extract the required information to show on the webpage of a single term """
        cf_term = term
        vs_term = self._select_versions_term(term["term_iri"])
        term_iri = term['term_iri']

        term_data = {}
        term_data["name"] = term_iri.split("/")[-1]
        term_data["uri"] = term_iri
        term_data["label"] = vs_term['label']
        term_data["class"] = cf_term['organized_in']
        term_data["definition"] = vs_term['definition']
        term_data["comments"] = cf_term['comments']
        term_data["rdf_type"] = vs_term['rdf_type']
        return term_data

    def process_terms(self):
        """parse the config terms towards the structure required for the HTML template"""

        template_data = []
        in_class = "Record-level"
        # sequence matters in config and it starts with Record-level
        class_group = {}
        class_group["name"] = "Record-level"
        class_group["uri"] = None
        class_group["terms"] = []
        for term in self.config(): # sequence of the config file used as order
            term_data = self.get_term_definition(term)
            # new class encountered
            if term_data["rdf_type"] == "http://www.w3.org/2000/01/rdf-schema#Class":
                # store previous section in template_data
                template_data.append(class_group)
                #start new class group
                class_group = term_data
                class_group["terms"] = []
                in_class = term_data["label"] # check on the class working in
            else:
                class_group['terms'].append(term_data)
        # save the last class to template_data
        template_data.append(class_group)
        return template_data

    @staticmethod
    def create_html(template_data, html_template="./config/index.tmpl", html_output="../guides/index.html"):
        """build html with the processed term info"""

        data={}
        data["groups"] = template_data
        html = Template(file=html_template, searchList=[data])

        index_page = open(html_output, "w")
        index_page.write(str(html))
        index_page.close()


def main():
    """Building up the html"""

    config_terms_file = "./config/terms.csv"
    term_versions_file = "../vocabulary/term_versions.csv"

    print("Running build process using current term_versions and config_terms file...")
    my_dwc = DwcDigester(term_versions_file, config_terms_file)
    print("Building index html file...")
    my_dwc.create_html(my_dwc.process_terms())
    print("...done!")


if __name__ == "__main__":
    sys.exit(main())