import datetime
import logging

from fastapi import FastAPI
from fastapi.responses import FileResponse
from pydantic import BaseModel
import pypandoc
import json
import httpx
from fastapi.testclient import TestClient
import os
from wand.image import Image
from wand.color import Color
import shutil


class DocumentSpecs(BaseModel):
    format: str
    style: str
    linkcolor: str
    tocdepth: int
    pdfengine: str
    content: str
    fontsize: int
    paperwidth: int
    paperheight: int
    margin: int
    extension: str

def convert_pdf_jpg(filename, output_path, resolution=300):
    """ Convert a PDF into images.

        All the pages will give a single png file with format:
        {pdf_filename}-{page_number}.png

        The function removes the alpha channel from the image and
        replace it with a white background.
    """
    all_pages = Image(filename=filename, resolution=resolution)
    for i, page in enumerate(all_pages.sequence):
        with Image(page) as img:
            img.format = 'jpg'
            img.background_color = Color('black')
            #img.alpha_channel = 'remove'

            image_filename = os.path.splitext(os.path.basename(filename))[0]
            image_filename = '{}-{}.jpg'.format(image_filename, i)
            image_filename = os.path.join(output_path, image_filename)

            img.save(filename=image_filename)

app = FastAPI()


@app.get("/generer/")
async def generer(specs: DocumentSpecs):
    header_file = f'{os.getcwd()}/styles/{specs.style}/{specs.format}/header.tex'
    cover_file = f'{os.getcwd()}/styles/{specs.style}/{specs.format}/cover.tex'
    datef = datetime.datetime.now().strftime("%m-%d-%Y")
    output_file = f"./{specs.style}-{specs.format}-{datef}-output.pdf"
    filters = []
    pdoc_args = [
        f'--include-in-header={header_file}',
        f'--include-after-body={cover_file}',
        '--listings',
        '--dpi=300',
        f'--toc-depth={specs.tocdepth}',
        f'--pdf-engine={specs.pdfengine}',
        '-V',f'linkcolor={specs.linkcolor}',
        '-V',f'fontsize={specs.fontsize}pt',
        '-V',f'geometry:paperwidth={specs.paperwidth/300}in',
        '-V',f'geometry:paperheight={specs.paperheight/300}in',
        '-V',f'geometry:margin={specs.margin/300}in'
    ]
    try:
        logging.info("Dossier courant = " + os.getcwd())

        result = pypandoc.convert_text(source=specs.content,
                                       to='pdf',
                                       format='markdown+implicit_figures+smart',
                                       encoding='utf-8',
                                       extra_args=pdoc_args,
                                       filters=filters,
                                       cworkdir=os.getcwd(),
                                       outputfile=output_file
                                       )

    except RuntimeError as rerr:
        logging.exception(rerr)
    except OSError as oerr:
        logging.exception(oerr)
    if specs.extension=="zip":
        zip_filename = os.path.splitext(os.path.basename(output_file))[0]
        png_output_dir = "./png_output"
        if not os.path.exists(png_output_dir):
            os.mkdir(png_output_dir)
        try:
            convert_pdf_jpg(output_file, png_output_dir, resolution=300)
            shutil.make_archive(zip_filename, 'zip', png_output_dir)
            shutil.rmtree(png_output_dir)
        except Exception as e:
            logging.exception(e)
        return FileResponse(zip_filename+".zip")
    elif specs.extension=="pdf":
        return FileResponse(output_file)
    else:
        return 0

client = TestClient(app)


def test_generer():
    test_json = json.read("test.json")
    response = client.get("/generer/", json=test_json)
    assert response.status_code == 200