"""
Utility: Analyze the results of fccs_reorganize.py.

Internal-use console report. Walks the configured output_dir looking for
_unparsed folders (files the reorganizer couldn't match against a folder
template) and summarizes what it finds, so gaps in fccs_folders.txt are easy
to spot.

Because unparsed files keep their original export filename
({drawer}_{client}_{folder}_{MM-DD-YYYY}_{doc}.ext), the folder field can
still be recovered from the name. The report aggregates those folder fields
(with years generalized back to YYYY) into suggested template lines you can
paste straight into fccs_folders.txt, then re-run the reorganizer.

Usage:
  python fccs_report_reorganize.py [--config path\\to\\config.ini]
"""

import os
import re
import sys

from fccs_config import parse_args, load_config

# Creation-date field that terminates the folder portion of the filename.
_DATE_RE = re.compile(r"_(\d{2}-\d{2}-\d{4})_")
# A standalone year inside a folder name, e.g. "2013 Tax Documents".
_YEAR_RE = re.compile(r"\b(19|20)\d{2}\b")

UNPARSED_DIRNAME = "_unparsed"


def folder_field_from_filename(filename):
    """Recover the folder field from an unparsed export filename, or None.

    Format: {drawer}_{client}_{folder}_{MM-DD-YYYY}_{doc}.ext
    Drawer and client are the first two underscore tokens (client names never
    contain underscores); the folder field runs from there to the first
    creation-date anchor.
    """
    stem = os.path.splitext(filename)[0]
    parts = stem.split("_", 2)
    if len(parts) < 3:
        return None
    rest = parts[2]  # folder + date + doc

    m = _DATE_RE.search("_" + rest)
    if not m:
        return None
    folder = rest[: max(m.start() - 1, 0)].strip("_").strip()
    return folder or None


def suggest_template(folder_field):
    """Generalize a concrete folder field into an fccs_folders.txt line.

    e.g. "2013 Tax Documents" -> "YYYY Tax Documents". Fields without a year
    are suggested as-is (static folders).
    """
    return _YEAR_RE.sub("YYYY", folder_field)


def main():
    args = parse_args()
    cfg = load_config(args.config)
    output_dir = cfg.get("paths", "output_dir")

    if not os.path.isdir(output_dir):
        print(f"ERROR: output directory not found: {output_dir}")
        sys.exit(1)

    clients_total = 0
    clients_with_unparsed = []   # (client_name, [filenames])
    top_level_unparsed = []      # filenames in output/_unparsed

    for name in sorted(os.listdir(output_dir)):
        path = os.path.join(output_dir, name)
        if not os.path.isdir(path):
            continue
        if name == UNPARSED_DIRNAME:
            top_level_unparsed = sorted(
                f for f in os.listdir(path)
                if os.path.isfile(os.path.join(path, f))
            )
            continue

        clients_total += 1
        up = os.path.join(path, UNPARSED_DIRNAME)
        if os.path.isdir(up):
            files = sorted(
                f for f in os.listdir(up)
                if os.path.isfile(os.path.join(up, f))
            )
            if files:
                clients_with_unparsed.append((name, files))

    print("=" * 64)
    print("REORGANIZE RESULTS REPORT")
    print(f"Output directory : {output_dir}")
    print(f"Client folders   : {clients_total}")
    print(f"With _unparsed   : {len(clients_with_unparsed)}")
    print(f"Top-level _unparsed (no client recovered): {len(top_level_unparsed)}")
    print("=" * 64)

    if not clients_with_unparsed and not top_level_unparsed:
        print("CLEAN — no _unparsed folders found. All files matched a "
              "folder template.")
        return

    # Aggregate folder fields across every unparsed file to point at the
    # template gaps directly.
    suggestions = {}   # suggested template line -> file count
    unrecovered = 0    # unparsed files whose folder field couldn't be read

    print()
    for client, files in clients_with_unparsed:
        print(f"{client}  ({len(files)} unparsed)")
        for f in files:
            field = folder_field_from_filename(f)
            if field:
                key = suggest_template(field)
                suggestions[key] = suggestions.get(key, 0) + 1
            else:
                unrecovered += 1
            print(f"    {f}")
        print()

    if top_level_unparsed:
        print(f"{UNPARSED_DIRNAME}/  (top level — client unknown, "
              f"{len(top_level_unparsed)} files)")
        for f in top_level_unparsed:
            field = folder_field_from_filename(f)
            if field:
                key = suggest_template(field)
                suggestions[key] = suggestions.get(key, 0) + 1
            else:
                unrecovered += 1
            print(f"    {f}")
        print()

    if suggestions:
        print("-" * 64)
        print("Possible missing folder templates (add to fccs_folders.txt,")
        print("then re-run fccs_reorganize.py):")
        for tmpl, count in sorted(suggestions.items(),
                                  key=lambda kv: (-kv[1], kv[0])):
            print(f"  {count:4d} x  {tmpl}")
    if unrecovered:
        print(f"\n{unrecovered} unparsed file(s) had no recoverable folder "
              "field (no date anchor in the name) — likely oddball names, "
              "not template gaps.")


if __name__ == "__main__":
    main()