import os
import sys
import tempfile
from zipfile import ZipFile, ZIP_DEFLATED
from datetime import datetime
import time
from jinja2 import Environment, FileSystemLoader
from . import Color

if getattr(sys, "frozen", False):
    _basedir = os.path.join(sys._MEIPASS, "pyexcelerate")
else:
    _basedir = os.path.dirname(__file__)
_TEMPLATE_PATH = os.path.join(_basedir, "templates")


class Writer(object):
    env = Environment(loader=FileSystemLoader(_TEMPLATE_PATH), auto_reload=False)
    _docProps_app_template = env.get_template("docProps/app.xml")
    _docProps_core_template = env.get_template("docProps/core.xml")
    _content_types_template = env.get_template("[Content_Types].xml")
    _rels_template = env.get_template("_rels/.rels")
    _styles_template = env.get_template("xl/styles.xml")
    _empty_styles_template = env.get_template("xl/styles.empty.xml")
    _workbook_template = env.get_template("xl/workbook.xml")
    _workbook_rels_template = env.get_template("xl/_rels/workbook.xml.rels")
    _worksheet_template = env.get_template("xl/worksheets/sheet.xml")
    _vbaProject_bin_file = os.path.join(_TEMPLATE_PATH, "xl/vbaProject.bin")
    __slots__ = ("workbook",)

    def __init__(self, workbook):
        self.workbook = workbook

    def _render_template_wb(self, template, extra_context=None):
        context = {"workbook": self.workbook}
        if extra_context:
            context.update(extra_context)
        return template.render(context).encode("utf-8")

    def _get_utc_now(self):
        now = datetime.utcnow()
        return now.strftime("%Y-%m-%dT%H:%M:00Z")

    def save(self, file, **kwargs):
        zf = ZipFile(file, "w", ZIP_DEFLATED, **kwargs)
        zf.writestr(
            "docProps/app.xml", self._render_template_wb(self._docProps_app_template)
        )
        zf.writestr(
            "docProps/core.xml",
            self._render_template_wb(
                self._docProps_core_template, {"date": self._get_utc_now()}
            ),
        )
        zf.writestr(
            "[Content_Types].xml",
            self._render_template_wb(self._content_types_template),
        )
        zf.writestr("_rels/.rels", self._rels_template.render().encode("utf-8"))
        if self.workbook.has_styles:
            zf.writestr(
                "xl/styles.xml", self._render_template_wb(self._styles_template)
            )
        else:
            zf.writestr(
                "xl/styles.xml", self._render_template_wb(self._empty_styles_template)
            )
        if self.workbook.has_macros:
            zf.write(self._vbaProject_bin_file, "xl/vbaProject.bin")
        zf.writestr(
            "xl/workbook.xml", self._render_template_wb(self._workbook_template)
        )
        zf.writestr(
            "xl/_rels/workbook.xml.rels",
            self._render_template_wb(self._workbook_rels_template),
        )
        for index, sheet in self.workbook.get_xml_data():
            sheetStream = self._worksheet_template.generate({"worksheet": sheet})
            try:
                with zf.open("xl/worksheets/sheet%s.xml" % (index), mode="w") as f:
                    for s in sheetStream:
                        f.write(s.encode("utf-8"))
            except RuntimeError:
                tfd, tfn = tempfile.mkstemp()
                tf = os.fdopen(tfd, "wb")
                for s in sheetStream:
                    tf.write(s.encode("utf-8"))
                tf.close()
                zf.write(tfn, "xl/worksheets/sheet%s.xml" % (index))
                os.remove(tfn)
        zf.close()