"""
Shared configuration, logging, and utilities for the FCCS extraction tool.
"""

import os
import re
import sys
import argparse
import configparser
from datetime import datetime

DEFAULT_CONFIG = "config.ini"


def parse_args():
    """Parse the optional --config argument common to all scripts."""
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--config",
        default=None,
        help=f"Path to config file (default: {DEFAULT_CONFIG} in script directory)",
    )
    return parser.parse_args()


def load_config(path=None):
    """Read config.ini and return a ConfigParser object."""
    if path is None:
        script_dir = os.path.dirname(os.path.abspath(sys.argv[0]))
        path = os.path.join(script_dir, DEFAULT_CONFIG)
    if not os.path.exists(path):
        print(f"ERROR: config file not found: {path}")
        sys.exit(1)
    cfg = configparser.ConfigParser()
    cfg.read(path, encoding="utf-8")
    return cfg


def make_logger(log_file):
    """Return a log() function that writes timestamped lines to console and file."""
    def log(msg):
        line = f"[{datetime.now():%Y-%m-%d %H:%M:%S}] {msg}"
        print(line)
        try:
            with open(log_file, "a", encoding="utf-8") as f:
                f.write(line + "\n")
        except Exception:
            pass
    return log


def load_folder_list(path):
    """Load known FCCS folder names from file, one per line."""
    if not os.path.exists(path):
        print(f"ERROR: folder list file not found: {path}")
        sys.exit(1)
    folders = []
    with open(path, "r", encoding="utf-8") as f:
        for line in f:
            s = line.strip()
            if s and not s.startswith("#"):
                folders.append(s)
    return folders


def build_folder_patterns(templates):
    """
    Convert folder template strings into regex patterns for matching.

    Templates use YYYY as a year placeholder (e.g. 'YYYY Tax Documents').
    Non-recurring folders (no YYYY) are matched literally.
    A built-in pattern for 'UltraTax CS MM-DD-YYYY' is always included.

    Returns a list of (compiled_regex, template_name, folder_type) tuples,
    sorted longest-first to prevent partial matches.

    folder_type is one of:
      "yyyy"     — recurring folder with year prefix (captured in group 1)
      "ultratax" — UltraTax CS folder with date suffix (captured in group 1)
      "static"   — non-recurring folder, no decomposition needed
    """
    patterns = []

    # Built-in: UltraTax CS folders (auto-generated by UltraTax integration)
    patterns.append((
        re.compile(r"UltraTax CS (\d{2}-\d{2}-\d{4})$"),
        "UltraTax CS",
        "ultratax",
    ))

    for tmpl in templates:
        if "YYYY" in tmpl:
            # Replace YYYY with captured 4-digit year pattern, escape the rest
            parts = tmpl.split("YYYY")
            regex_str = re.escape(parts[0]) + r"(\d{4})" + re.escape(parts[1])
            patterns.append((re.compile(regex_str + "$"), tmpl, "yyyy"))
        else:
            # Non-recurring folder — exact match
            regex_str = re.escape(tmpl)
            patterns.append((re.compile(regex_str + "$"), tmpl, "static"))

    # Sort by regex pattern length (longest first) to avoid partial matches
    patterns.sort(key=lambda p: len(p[0].pattern), reverse=True)
    return patterns


def decompose_folder_path(match, folder_type, template_name):
    """
    Decompose a matched folder name into nested path components that
    recreate the FCCS UI folder structure.

    Returns a tuple of path parts to be joined with os.path.join().

    Examples:
      yyyy:     "YYYY Tax Documents" matched "2025 Tax Documents"
                → ("Tax Documents", "2025")
      ultratax: "UltraTax CS 12-31-2008"
                → ("UltraTax CS", "12-31-2008")
      static:   "Permanent File"
                → ("Permanent File",)
    """
    if folder_type == "yyyy":
        year = match.group(1)
        # Strip "YYYY " from template to get the base folder name
        base_name = template_name.replace("YYYY", "").strip()
        return (base_name, year)
    elif folder_type == "ultratax":
        date = match.group(1)
        return ("UltraTax CS", date)
    else:
        return (template_name,)


def load_lines(path):
    """Read non-blank, non-comment lines from a file."""
    if not os.path.exists(path):
        return []
    with open(path, "r", encoding="utf-8") as f:
        return [line.strip() for line in f if line.strip() and not line.strip().startswith("#")]


def check_for_clashes(drawer_ids):
    """Find drawer IDs that are a prefix of another drawer ID.

    FCCS searches by prefix, so searching the shorter ID (e.g. '02218')
    pops up a selection box when a longer ID exists (e.g. '02218A'),
    which breaks the automated navigation.

    Returns a list of (short_id, [longer_ids...]) tuples, sorted by short_id.
    Empty list means no clashes.
    """
    ids = sorted(set(drawer_ids))
    clashes = []
    for short in ids:
        matches = [other for other in ids
                   if other != short and other.startswith(short)]
        if matches:
            clashes.append((short, matches))
    return clashes