#!/usr/bin/env python3
# This tool generates emoji_names.py from a CSV file passed in on the command line.
#
# The CSV files come from a Google Sheets document, because that's a
# better format for reviewing all the emoji and thinking about what
# names and aliases make the most sense; this script converts the
# easily exported CSV one can get from Google Sheets into the
# emoji_names.py format for consumption by the rest of our emoji
# tooling.  We check in emoji_names.py (not the CSV) whenever we rerun
# this tool to update the data.
import argparse
import csv
import os
import re
import textwrap

from typing import Any, Dict, List, Set

EMOJI_DIR_PATH = os.path.dirname(os.path.abspath(__file__))

ACTIVE_ENTRY = (
    "%(explanation)s"
    "\n    '%(emoji_code)s': {'canonical_name': '%(canonical_name)s', 'aliases': %(aliases)s},"
)

INACTIVE_ENTRY = (
    "%(explanation)s"
    "\n    # '%(emoji_code)s': {'canonical_name': '%(canonical_name)s', 'aliases': %(aliases)s},"
)

FILE_TEMPLATE = (
    "from typing import Any, Dict\n\n"
    "EMOJI_NAME_MAPS = {"
    "%(emoji_entries)s\n"
    "}   # type: Dict[str, Dict[str, Any]]\n"
)

emoji_names: Set[str] = set()

def load_data(data_file: str) -> List[List[str]]:
    emoji_name_data: List[List[str]] = []
    with open(data_file, newline='') as fp:
        data = csv.reader(fp)
        for row in data:
            emoji_name_data.append(row)
    return emoji_name_data[1:]

def check_uniqueness(emoji_name: str) -> None:
    if emoji_name in emoji_names:
        raise Exception("Duplicate emoji name: %s" % (emoji_name,))
    emoji_names.add(emoji_name)

def check_valid_emoji_name(emoji_name: str) -> None:
    if re.fullmatch("[+-]?[a-z0-9_-]+", emoji_name) is None:
        raise Exception("Invalid emoji name: %s" % (emoji_name,))

def check_emoji_names(canonical_name: str, aliases: List[str]) -> None:
    if canonical_name == 'X':
        return
    names_to_check = [canonical_name, ] + aliases
    for name in names_to_check:
        check_valid_emoji_name(name)
        check_uniqueness(name)

def prepare_explanation(explanation: str) -> str:
    if explanation == '':
        return ''

    wrapper_config: Dict[str, Any] = {
        'width': 80,
        'break_long_words': False,
        'break_on_hyphens': False,
        'initial_indent': '\n    # ',
        'subsequent_indent': '\n    # ',
    }
    wrapped_lines = textwrap.wrap(explanation.strip(), **wrapper_config)
    return ''.join(wrapped_lines)

def prepare_aliases(aliases: str) -> List[str]:
    if aliases == '':
        return []
    return [alias.strip() for alias in aliases.split(',')]

def main() -> None:
    description = ("This script is used for generating `emoji_names.py`. It takes the "
                   "path of an csv file containing the required data and optional output "
                   "file path.")
    parser = argparse.ArgumentParser(description=description)
    parser.add_argument(
        "--input-file", dest="input_file_path", type=str, metavar="<path>",
        default=os.path.join(EMOJI_DIR_PATH, "emoji_names.csv"),
        help="Path to the csv file from which data is to be read.")
    parser.add_argument(
        "--output-file", dest="output_file_path", type=str, metavar="<path>",
        default=os.path.join(EMOJI_DIR_PATH, "emoji_names.py"),
        help="Path to the output file.")

    args = parser.parse_args()
    emoji_name_data = load_data(args.input_file_path)
    emoji_entry = ""
    emoji_entries = ""

    for row in emoji_name_data:
        emoji_code = row[0]
        canonical_name = row[2]
        aliases = row[3]
        explanation = row[4]

        formatted_explanation = prepare_explanation(explanation)
        extracted_aliases = prepare_aliases(aliases)
        check_emoji_names(canonical_name, extracted_aliases)

        context = {
            'emoji_code': emoji_code,
            'canonical_name': canonical_name,
            'aliases': extracted_aliases,
            'explanation': formatted_explanation,
        }
        if canonical_name == 'X':
            emoji_entry = INACTIVE_ENTRY % dict(**context)
        else:
            emoji_entry = ACTIVE_ENTRY % dict(**context)

        # If an entry is longer than 120 then append
        # `    # ignorelongline` to avoid lint errors.
        if len(emoji_entry.split('\n')[-1]) >= 110:
            emoji_entry += '    # ignorelongline'
        emoji_entries += emoji_entry

    with open(args.output_file_path, 'w') as fp:
        fp.write(FILE_TEMPLATE % {'emoji_entries': emoji_entries})

if __name__ == '__main__':
    main()
