#!/usr/bin/env python3

import argparse
import math
import operator

import fpdf
import strictyaml


class Chart:
    def __init__(self):
        self.parser = self.get_parser()
        self.args = self.parser.parse_args()
        self.data = strictyaml.load(self.args.chart_data.read()).data

    def get_parser(self):
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "chart_data",
            type=argparse.FileType("r")
        )
        parser.add_argument(
            "--output",
            type=argparse.FileType("w"),
            default=None,
            help="Destination file",
        )
        parser.add_argument(
            "--columns", "-c",
            default=4,
            type=int,
            help="Number of columns per page",
        )
        parser.add_argument(
            "--rows", "-r",
            default=16,
            type=int,
            help="Number of rows per page",
        )
        parser.add_argument(
            "--index-columns", "-i",
            default=6,
            type=int,
            help="Number of columns per index page",
        )
        parser.add_argument(
            "--background-fill", "-b",
            action=argparse.BooleanOptionalAction,
            default=True,
            help="Fill the background with the target colour",
        )
        return parser

    def get_arranged_cells(self):
        per_page = self.args.columns * self.args.rows
        padded = self.data["colours"] + [{}] * (
            per_page - len(self.data["colours"]) % per_page
        )
        pages = [
            padded[i * per_page:i * per_page + per_page]
            for i in range(len(padded) // per_page)
        ]
        cells = [
            [
                [p[i + self.args.rows * j] for j in range(self.args.columns)]
                for i in range(len(p) // self.args.columns)
            ]
            for p in pages
        ]
        return(cells)

    def get_index(self):
        index = [
            (c["label"], i // self.args.rows)
            for i, c in enumerate(self.data["colours"])
        ]
        index.sort(key=operator.itemgetter(0))
        return index

    def write_pdf(self):
        pdf = fpdf.FPDF(format="A5")
        pdf.add_font(
            family="FreeSans",
            fname="/usr/share/fonts/opentype/freefont/FreeSans.otf",
        )
        pdf.add_font(
            family="FreeSans",
            style="B",
            fname="/usr/share/fonts/opentype/freefont/FreeSansBold.otf",
        )
        pdf.add_font(
            family="FreeSerif",
            fname="/usr/share/fonts/opentype/freefont/FreeSerif.otf",
        )

        for p_num, page in enumerate(self.get_arranged_cells()):
            pdf.add_page()
            pdf.set_font("FreeSerif", size=10)
            cell_width = (148 - 20) / (self.args.columns * 2)
            pdf.cell(64, 8, self.data["title"], align="C")
            pdf.ln()
            pdf.set_font("FreeSans", "B", 10)
            for j in range(self.args.columns):
                pdf.cell(cell_width, 8, str(j + p_num * self.args.columns),)
                pdf.cell(cell_width, 8, "")
            pdf.ln()
            for row in page:
                for cell in row:
                    if cell:
                        pdf.set_fill_color(255,255,255)
                        if self.args.background_fill and cell.get("bg"):
                            pdf.set_fill_color(*map(int, cell["bg"].split()))
                        pdf.cell(cell_width, 8, "", border=1, fill=True)
                        pdf.cell(cell_width, 8, cell["label"], )
                pdf.ln(10)

        pdf.add_page()
        pdf.set_font("FreeSerif", size=10)
        cell_width = (148 - 20) / (self.args.columns * 2)
        pdf.cell(64, 8, self.data["title"], align="C")
        pdf.ln()
        pdf.set_font("FreeSerif", size=10)
        with pdf.text_columns(
            ncols=self.args.index_columns,
            balance=True,
            gutter=4,
            text_align="RIGHT",
        ) as cols:
            for c in self.get_index():
                pdf.set_font("FreeSerif", size=10)
                cols.write(str(c[0]))
                cols.write("  ")
                pdf.set_font("FreeSans", "B", size=10)
                cols.write(str(c[1]))
                cols.ln()

        fname = (
            getattr(self.args.output, "name", None) or
            self.args.chart_data.name.replace(".yaml", ".pdf")
        )
        print(fname)
        pdf.output(fname)


if __name__ == "__main__":
    Chart().write_pdf()