import csv
import re
from pathlib import Path
from itertools import chain


class IFTConverter:
    def __init__(self, base_dir):
        self.config = {
            "_A_": {
                "1": self.import_config(base_dir + "actuals_header.txt"),
                "2": self.import_config(base_dir + "actuals_item.txt"),
            },
            "_B_": {"010": self.import_config(base_dir + "budget_line.txt")},
            "_C_": {"010": self.import_config(base_dir + "commitment_line.txt")},
            "_K_": {
                "1": self.import_config(base_dir + "controllingdoc_header.txt"),
                "2": self.import_config(base_dir + "controllingdoc_item.txt"),
            },
            "_P_": {"010": self.import_config(base_dir + "plan_line.txt")},
        }
        self.is_number = re.compile(r"\d+\.\d+\-?$")

    def import_config(self, filename):
        with open(filename, "r") as frh:
            return [
                (int(line["start"]) - 1, int(line["start"]) + int(line["length"]) - 1)
                for line in csv.DictReader(frh, delimiter="\t")
            ]

    def convert_dir(self, path):
        source_path = Path(path)
        target_path = source_path.parent.joinpath("staging")

        for filename in source_path.glob("*"):
            print(filename.name)
            if filename.name.count("_") < 2:
                print("-> wrong file format")
            elif filename.stat().st_size == 0:
                print("-> file is empty!")
            else:
                self.convert_file(filename, target_path)

    def convert_file(self, source, target_path):
        cfg = self.conversion_config(source.name)
        target = target_path.joinpath(source.name + ".csv")

        content = {}
        last_key = list(cfg.keys())[-1]

        with open(source, "r", encoding="utf-8", errors="ignore") as frh:
            with open(target, "w", encoding="utf-8") as fwh:
                for line in frh.readlines():
                    for key, rules in cfg.items():
                        if line.startswith(key):
                            content[key] = self.convert_line(line, rules)
                            break
                    if line.startswith(last_key):
                        fwh.write("\t".join(chain(*content.values())) + "\n")

    def convert_line(self, line, rules):
        return [self.convert_field(line, rule) for rule in rules]

    def convert_field(self, line, rule):
        field = line[rule[0] : rule[1]].strip()
        if self.is_number.search(field):
            field = field.replace(",", "")
            if field[-1] == "-":
                field = "-" + field[:-1]
        return field

    def conversion_config(self, filename):
        for key, cfg in self.config.items():
            if key in filename:
                return cfg
        return {"0": []}


def main():
    ift_conv = IFTConverter("E:\\GlobalCube\\Tasks\\Import\\config\\IFT\\")
    ift_conv.convert_dir("E:\\IFT\\prod")


if __name__ == "__main__":
    main()