#!/usr/bin/env python3
"""
orchestrate_cr.py — Fully automated CR application pipeline.

Reads an Excel contribution list, downloads all Accepted CRs and their target
TSs, parses tracked changes from each CR, applies them to the TS, and
finalises the document metadata — all without any per-CR manual scripting.

Usage:
    python3 orchestrate_cr.py <excel_path> [person_name] [--output-dir DIR] [--author NAME]

Arguments:
    excel_path   Path to .xls or .xlsx contribution list (Windows paths OK)
    person_name  Name to match in SubmittedBy column (default: "Ly Thanh PHAN")

Options:
    --output-dir  Base output folder (default: ~/CR_Processing)
    --author      Tracked-change author name (default: "CR Application")
"""

import argparse
import contextlib
import datetime
import io
import json
import os
import re
import sys
import time
from pathlib import Path

import docx as docx_lib

# ── sys.path setup ────────────────────────────────────────────────────────────
SCRIPT_DIR = Path(__file__).parent
FETCH_SCRIPTS = SCRIPT_DIR.parent.parent / 'fetch-crs' / 'scripts'
sys.path.insert(0, str(SCRIPT_DIR))
sys.path.insert(0, str(FETCH_SCRIPTS))

from fetch_crs import parse_excel, download_cr, parse_cr_cover, download_ts, wsl_path
from cr_parser import parse_cr
from ts_applicator import apply_manifest
from finalize_ts import (
    extract_cr_metadata,
    compute_pub_date,
    derive_new_version,
    update_change_history_table,
    update_history_table,
    update_title_para,
    NoChangeHistoryTable,
)
from docx_helpers import RevCounter, AUTHOR as DEFAULT_AUTHOR, DATE as DEFAULT_DATE


# ── Display / logging helpers ─────────────────────────────────────────────────

def _section(title):
    bar = '=' * 60
    print(f'\n{bar}')
    print(f'  {title}')
    print(bar)


class _TeeWriter:
    """Writes to both real stdout and a StringIO buffer simultaneously."""
    def __init__(self, real, buf):
        self._real = real
        self._buf = buf

    def write(self, s):
        self._real.write(s)
        self._buf.write(s)

    def flush(self):
        self._real.flush()


# ── Main ──────────────────────────────────────────────────────────────────────

def main():
    ap = argparse.ArgumentParser(
        description='Fully automated CR application pipeline.',
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    ap.add_argument(
        'excel_path',
        nargs='?',
        default=None,
        help='Path to .xls or .xlsx contribution list (not required in --retry-mode)',
    )
    ap.add_argument(
        'person_name',
        nargs='?',
        default='Ly Thanh PHAN',
        help='Name to match in SubmittedBy column (default: "Ly Thanh PHAN")',
    )
    ap.add_argument(
        '--output-dir',
        default=str(Path.home() / 'CR_Processing'),
        help='Base output directory (default: ~/CR_Processing)',
    )
    ap.add_argument(
        '--author',
        default=DEFAULT_AUTHOR,
        help=f'Tracked change author name (default: "{DEFAULT_AUTHOR}")',
    )
    ap.add_argument(
        '--retry-mode',
        action='store_true',
        help='Skip steps 1-4; apply CRs to TSs listed in failed_ts.json that now have their DOCX on disk',
    )
    args = ap.parse_args()

    if not args.retry_mode and not args.excel_path:
        ap.error('excel_path is required when not in --retry-mode')

    eol_user = os.environ.get("EOL_USER", "")
    eol_password = os.environ.get("EOL_PASSWORD", "")
    if not eol_user or not eol_password:
        sys.exit("ERROR: EOL_USER and EOL_PASSWORD must be set")

    output_dir = Path(wsl_path(args.output_dir)).expanduser()
    cr_dir = output_dir / 'CRs'
    ts_dir = output_dir / 'TS'   # spec subfolders created per-TS below
    cr_dir.mkdir(parents=True, exist_ok=True)
    ts_dir.mkdir(parents=True, exist_ok=True)

    author = args.author
    tc_date = DEFAULT_DATE

    # ── Retry mode — skip steps 1-4, reconstruct state from failed_ts.json ───
    if args.retry_mode:
        failed_ts_path = output_dir / 'failed_ts.json'
        if not failed_ts_path.exists():
            sys.exit('ERROR: failed_ts.json not found in output directory')
        failed_ts_entries = json.loads(failed_ts_path.read_text())
        if not failed_ts_entries:
            print('No failed TSs in failed_ts.json — nothing to retry.')
            return

        _section('Retry mode — Steps 5 & 6 only')
        print(f'Retrying {len(failed_ts_entries)} TS(s) from failed_ts.json')

        ts_groups = {}
        spec_dirs = {}
        ts_paths = {}
        cr_paths = {}

        for entry in failed_ts_entries:
            spec_number = entry['spec_number']
            version = entry['version']
            key = (spec_number, version)
            ts_groups[key] = entry['cr_uids']
            spec_dir = Path(entry['spec_dir'])
            spec_dirs[key] = spec_dir
            expected = spec_dir / entry['expected_filename']
            if expected.exists():
                ts_paths[key] = expected
                print(f'  [TS {spec_number} v{version}] DOCX found — will apply')
            else:
                print(f'  [TS {spec_number} v{version}] DOCX missing — skipping')
            # Reconstruct cr_paths for each UID
            cr_entry_dir = Path(entry['cr_dir'])
            for uid in entry['cr_uids']:
                extracted = cr_entry_dir / f'{uid}_extracted.docx'
                plain = cr_entry_dir / f'{uid}.docx'
                if extracted.exists():
                    cr_paths[uid] = extracted
                elif plain.exists():
                    cr_paths[uid] = plain

        # ── Steps 5 & 6 (retry mode falls through to shared loop below) ──────
        report = []

        for (spec_number, version), uids in ts_groups.items():
            ts_key = f'TS {spec_number} v{version}'
            spec_compact = spec_number.replace(' ', '')
            spec_dir = spec_dirs.get((spec_number, version), ts_dir / spec_compact)
            spec_dir.mkdir(parents=True, exist_ok=True)

            new_v = derive_new_version(version)
            stem = f'ts_{spec_compact}_v{new_v}_was_v{version}'
            ts_applied = spec_dir / f'ts_{spec_compact}_v{version}_applied.docx'
            ts_final   = spec_dir / f'{stem}.docx'
            log_path   = spec_dir / f'{stem}.log'
            errors = []

            print(f'\n-- {ts_key} ({len(uids)} CR(s): {", ".join(uids)}) --')

            if (spec_number, version) not in ts_paths:
                msg = 'TS DOCX not on disk — skipping'
                print(f'  SKIP: {msg}')
                report.append((ts_key, 0, 0, len(uids), None, log_path, [msg]))
                continue

            ts_in = ts_paths[(spec_number, version)]

            log_buf = io.StringIO()
            tee = _TeeWriter(sys.stdout, log_buf)

            with contextlib.redirect_stdout(tee):
                log_header = (
                    f'Pipeline Log (retry)\n'
                    f'TS:   {spec_number}  v{version} -> v{new_v}\n'
                    f'CRs:  {", ".join(uids)}\n'
                    f'Date: {datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")}\n'
                    f'{"=" * 60}\n'
                )
                print(log_header, end='')

                combined_manifest = []
                participating_uids = []

                for uid in uids:
                    if uid not in cr_paths:
                        errors.append(f'[{uid}] CR DOCX not found — skipped')
                        continue
                    print(f'  Parsing {uid}... ', end='', flush=True)
                    try:
                        changes = parse_cr(cr_paths[uid])
                        combined_manifest.extend(changes)
                        participating_uids.append(uid)
                        print(f'{len(changes)} change(s)')
                    except Exception as e:
                        errors.append(f'[{uid}] parse ERROR: {e}')
                        print(f'ERROR: {e}')

                if not combined_manifest:
                    print('  No changes parsed — skipping apply step.')
                    report.append((ts_key, 0, 0, len(uids), None, log_path,
                                    errors + ['No changes parsed']))
                    log_path.write_text(log_buf.getvalue(), encoding='utf-8')
                    continue

                print(f'  Applying {len(combined_manifest)} change(s) to {ts_in.name}...')
                try:
                    n_ok, n_skip, log_lines = apply_manifest(
                        ts_in, combined_manifest, ts_applied, author=author, date=tc_date
                    )
                except Exception as e:
                    errors.append(f'apply_manifest ERROR: {e}')
                    print(f'  ERROR: {e}')
                    report.append((ts_key, 0, 0, len(uids), None, log_path, errors))
                    log_path.write_text(log_buf.getvalue(), encoding='utf-8')
                    continue

                for line in log_lines:
                    print(f'  {line}')
                # Bubble every un-applied change into the warnings list
                for line in log_lines:
                    if line.strip().startswith('ERROR'):
                        errors.append(line.strip())
                print(f'  -> Applied: {n_ok}  Skipped: {n_skip}')

                print('  Finalising metadata...')
                try:
                    ts_doc = docx_lib.Document(str(ts_applied))
                    rev = RevCounter(ts_doc)

                    pub_ym, pub_month_year = compute_pub_date()
                    old_v = version

                    title_text = ts_doc.paragraphs[0].text
                    date_match = re.search(r'\((\d{4}-\d{2})\)', title_text)
                    old_date_str = date_match.group(1) if date_match else ''

                    print(f'    Version:     {old_v} -> {new_v}')
                    print(f'    Publication: {pub_month_year} ({pub_ym})')

                    for uid in participating_uids:
                        try:
                            meta = extract_cr_metadata(str(cr_paths[uid]))
                            ch_cells = update_change_history_table(
                                ts_doc, meta, pub_ym, old_v, new_v, rev, author, tc_date
                            )
                            print(f'    [Change History] {uid}: {ch_cells}')
                        except NoChangeHistoryTable:
                            print(f'    [Change History] {uid}: NOT PRESENT — this document has no Change History table (History table only)')
                        except Exception as e:
                            errors.append(f'[{uid}] Change History ERROR: {e}')
                            print(f'    [Change History] {uid}: ERROR — {e}')

                    try:
                        h_cells = update_history_table(
                            ts_doc, new_v, pub_month_year, rev, author, tc_date
                        )
                        print(f'    [History] {h_cells}')
                    except Exception as e:
                        errors.append(f'History table ERROR: {e}')
                        print(f'    [History] ERROR — {e}')

                    if old_date_str:
                        try:
                            update_title_para(
                                ts_doc, old_v, new_v, old_date_str, pub_ym, rev, author, tc_date
                            )
                            print(f'    [Title] V{old_v} -> V{new_v}, ({old_date_str}) -> ({pub_ym})')
                        except Exception as e:
                            errors.append(f'Title update ERROR: {e}')
                            print(f'    [Title] ERROR — {e}')
                    else:
                        print(f'    [Title] SKIP — no (YYYY-MM) pattern in: {title_text!r}')

                    ts_doc.save(str(ts_final))
                    print(f'  Saved: {spec_compact}/{ts_final.name}')
                    print(f'  Log:   {spec_compact}/{log_path.name}')
                    report.append((ts_key, n_ok, n_skip, len(uids), ts_final, log_path, errors))

                except Exception as e:
                    errors.append(f'Finalisation ERROR: {e}')
                    print(f'  Finalisation ERROR: {e}')
                    report.append((ts_key, n_ok, n_skip, len(uids), ts_applied, log_path, errors))

            log_path.write_text(log_buf.getvalue(), encoding='utf-8')

        # Update failed_ts.json — remove entries that are now resolved
        still_failed = [
            e for e in failed_ts_entries
            if not (Path(e['spec_dir']) / e['expected_filename']).exists()
        ]
        failed_ts_path.write_text(json.dumps(still_failed, indent=2))

        _section('Retry Summary')
        n_success = sum(1 for r in report if r[4] is not None and not r[6])
        n_partial  = sum(1 for r in report if r[4] is not None and r[6])
        n_failed   = sum(1 for r in report if r[4] is None)
        print(f'TSs processed:  {n_success} fully OK, {n_partial} with warnings, {n_failed} skipped/failed')
        for ts_key, n_ok, n_skip, n_crs, out_path, log_path, errors in report:
            status_tag = 'OK' if out_path and not errors else ('WARN' if out_path else 'SKIP')
            print(f'  [{status_tag}] {ts_key}')
            for err in errors:
                print(f'         ! {err}')
        return

    excel_path = wsl_path(args.excel_path)

    # ── Step 1: Parse Excel ───────────────────────────────────────────────────
    _section('Step 1 — Parsing Excel')
    print(f'Excel:   {excel_path}')
    print(f'Person:  {args.person_name!r}')

    try:
        cr_list = parse_excel(excel_path, args.person_name)
    except Exception as e:
        sys.exit(f'ERROR parsing Excel: {e}')

    print(f'Found {len(cr_list)} Accepted CR(s)')

    if not cr_list:
        print('Nothing to process.')
        return

    # ── Step 2: Download CR DOCXs ─────────────────────────────────────────────
    _section('Step 2 — Downloading CR DOCXs')
    cr_paths = {}  # uid -> Path

    for uid, _ in cr_list:
        docx_path, note = download_cr(uid, cr_dir, eol_user, eol_password)
        if docx_path:
            cr_paths[uid] = docx_path
            print(f'  [{uid}] OK ({note}) — {docx_path.name}')

    n_cr_failed = len(cr_list) - len(cr_paths)
    if n_cr_failed:
        print(f'  {len(cr_paths)}/{len(cr_list)} downloaded ({n_cr_failed} failed — details in warnings)')
    else:
        print(f'  All {len(cr_list)} CR(s) downloaded successfully')

    # ── Step 3: Parse cover pages → group by target TS ───────────────────────
    _section('Step 3 — Parsing CR cover pages')
    ts_groups = {}  # (spec_number, version) -> [uid, ...]
    uid_cover_failed = []

    for uid in cr_paths:
        spec_number, version = parse_cr_cover(cr_paths[uid])
        if spec_number and version:
            key = (spec_number, version)
            ts_groups.setdefault(key, []).append(uid)
            print(f'  [{uid}] -> TS {spec_number}  v{version}')
        else:
            uid_cover_failed.append(uid)
            print(f'  [{uid}] WARNING: could not parse cover page — skipping')

    if not ts_groups:
        print('\nNo TSs identified. Nothing to apply.')
        return

    # ── Step 4: Download TSs ──────────────────────────────────────────────────
    _section('Step 4 — Downloading TSs')
    ts_paths = {}   # (spec_number, version) -> Path
    spec_dirs = {}  # (spec_number, version) -> Path (per-spec subfolder)

    for (spec_number, version) in ts_groups:
        spec_compact = spec_number.replace(' ', '')
        spec_dir = ts_dir / spec_compact
        spec_dir.mkdir(parents=True, exist_ok=True)
        spec_dirs[(spec_number, version)] = spec_dir

        print(f'  [TS {spec_number} v{version}] ', end='', flush=True)
        filename, note = None, "not attempted"
        for attempt in range(1, 4):
            filename, note = download_ts(spec_number, version, spec_dir, eol_user, eol_password)
            if filename:
                break
            if attempt < 3:
                print(f'\n    [attempt {attempt}/3 failed — retrying in 5s: {note}]', flush=True)
                print(f'  [TS {spec_number} v{version}] ', end='', flush=True)
                time.sleep(5)
            else:
                print(f'\n    [all 3 attempts failed]', flush=True)
        if filename:
            ts_paths[(spec_number, version)] = spec_dir / filename
            print(f'OK ({note}) — {spec_compact}/{filename}')
        else:
            print(f'FAILED — {note}')

    # Write failed_ts.json (even when empty so app.py can detect "no failures")
    failed_ts_entries = [
        {
            "spec_number":       spec_number,
            "version":           version,
            "spec_compact":      spec_number.replace(' ', ''),
            "spec_dir":          str(spec_dirs[(spec_number, version)]),
            "expected_filename": f"ts_{spec_number.replace(' ', '')}_v{version}.docx",
            "cr_uids":           ts_groups[(spec_number, version)],
            "cr_dir":            str(cr_dir),
        }
        for (spec_number, version) in ts_groups
        if (spec_number, version) not in ts_paths
    ]
    (output_dir / "failed_ts.json").write_text(
        json.dumps(failed_ts_entries, indent=2)
    )

    # ── Steps 5 & 6: Apply CRs + Finalise each TS ────────────────────────────
    _section('Steps 5 & 6 — Applying CRs and Finalising Metadata')
    report = []  # (ts_key, n_ok, n_skip, n_crs, out_path, log_path, errors)

    for (spec_number, version), uids in ts_groups.items():
        ts_key = f'TS {spec_number} v{version}'
        spec_compact = spec_number.replace(' ', '')
        spec_dir = spec_dirs.get((spec_number, version), ts_dir / spec_compact)
        spec_dir.mkdir(parents=True, exist_ok=True)

        # Derive new version early so filenames are known upfront
        new_v = derive_new_version(version)
        stem = f'ts_{spec_compact}_v{new_v}_was_v{version}'
        ts_applied = spec_dir / f'ts_{spec_compact}_v{version}_applied.docx'
        ts_final   = spec_dir / f'{stem}.docx'
        log_path   = spec_dir / f'{stem}.log'
        errors = []

        print(f'\n-- {ts_key} ({len(uids)} CR(s): {", ".join(uids)}) --')

        if (spec_number, version) not in ts_paths:
            msg = 'TS download failed — skipping'
            print(f'  SKIP: {msg}')
            report.append((ts_key, 0, 0, len(uids), None, log_path, [msg]))
            continue

        ts_in = ts_paths[(spec_number, version)]

        # All per-TS output is captured to log_buf (tee: stdout + file)
        log_buf = io.StringIO()
        tee = _TeeWriter(sys.stdout, log_buf)

        with contextlib.redirect_stdout(tee):
            log_header = (
                f'Pipeline Log\n'
                f'TS:   {spec_number}  v{version} -> v{new_v}\n'
                f'CRs:  {", ".join(uids)}\n'
                f'Date: {datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")}\n'
                f'{"=" * 60}\n'
            )
            print(log_header, end='')

            # 5a. Parse all CR manifests and combine
            combined_manifest = []
            participating_uids = []

            for uid in uids:
                if uid not in cr_paths:
                    errors.append(f'[{uid}] CR download had failed — skipped')
                    continue
                print(f'  Parsing {uid}... ', end='', flush=True)
                try:
                    changes = parse_cr(cr_paths[uid])
                    combined_manifest.extend(changes)
                    participating_uids.append(uid)
                    print(f'{len(changes)} change(s)')
                except Exception as e:
                    errors.append(f'[{uid}] parse ERROR: {e}')
                    print(f'ERROR: {e}')

            if not combined_manifest:
                print('  No changes parsed — skipping apply step.')
                report.append((ts_key, 0, 0, len(uids), None, log_path,
                                errors + ['No changes parsed']))
                log_path.write_text(log_buf.getvalue(), encoding='utf-8')
                continue

            # 5b. Apply manifest to TS
            print(f'  Applying {len(combined_manifest)} change(s) to {ts_in.name}...')
            try:
                n_ok, n_skip, log_lines = apply_manifest(
                    ts_in, combined_manifest, ts_applied, author=author, date=tc_date
                )
            except Exception as e:
                errors.append(f'apply_manifest ERROR: {e}')
                print(f'  ERROR: {e}')
                report.append((ts_key, 0, 0, len(uids), None, log_path, errors))
                log_path.write_text(log_buf.getvalue(), encoding='utf-8')
                continue

            for line in log_lines:
                print(f'  {line}')
            # Bubble every un-applied change into the warnings list
            for line in log_lines:
                if line.strip().startswith('ERROR'):
                    errors.append(line.strip())
            print(f'  -> Applied: {n_ok}  Skipped: {n_skip}')

            # 6. Finalise metadata (Change History, History, title paragraph)
            print('  Finalising metadata...')
            try:
                ts_doc = docx_lib.Document(str(ts_applied))
                rev = RevCounter(ts_doc)

                pub_ym, pub_month_year = compute_pub_date()
                old_v = version

                # Extract old date string from first paragraph
                title_text = ts_doc.paragraphs[0].text
                date_match = re.search(r'\((\d{4}-\d{2})\)', title_text)
                old_date_str = date_match.group(1) if date_match else ''

                print(f'    Version:     {old_v} -> {new_v}')
                print(f'    Publication: {pub_month_year} ({pub_ym})')

                # One Change History row per CR
                for uid in participating_uids:
                    try:
                        meta = extract_cr_metadata(str(cr_paths[uid]))
                        ch_cells = update_change_history_table(
                            ts_doc, meta, pub_ym, old_v, new_v, rev, author, tc_date
                        )
                        print(f'    [Change History] {uid}: {ch_cells}')
                    except NoChangeHistoryTable:
                        print(f'    [Change History] {uid}: NOT PRESENT — this document has no Change History table (History table only)')
                    except Exception as e:
                        errors.append(f'[{uid}] Change History ERROR: {e}')
                        print(f'    [Change History] {uid}: ERROR — {e}')

                # One History row for the whole TS
                try:
                    h_cells = update_history_table(
                        ts_doc, new_v, pub_month_year, rev, author, tc_date
                    )
                    print(f'    [History] {h_cells}')
                except Exception as e:
                    errors.append(f'History table ERROR: {e}')
                    print(f'    [History] ERROR — {e}')

                # Title paragraph version + date
                if old_date_str:
                    try:
                        update_title_para(
                            ts_doc, old_v, new_v, old_date_str, pub_ym, rev, author, tc_date
                        )
                        print(f'    [Title] V{old_v} -> V{new_v}, ({old_date_str}) -> ({pub_ym})')
                    except Exception as e:
                        errors.append(f'Title update ERROR: {e}')
                        print(f'    [Title] ERROR — {e}')
                else:
                    print(f'    [Title] SKIP — no (YYYY-MM) pattern in: {title_text!r}')

                ts_doc.save(str(ts_final))
                print(f'  Saved: {spec_compact}/{ts_final.name}')
                print(f'  Log:   {spec_compact}/{log_path.name}')
                report.append((ts_key, n_ok, n_skip, len(uids), ts_final, log_path, errors))

            except Exception as e:
                errors.append(f'Finalisation ERROR: {e}')
                print(f'  Finalisation ERROR: {e}')
                report.append((ts_key, n_ok, n_skip, len(uids), ts_applied, log_path, errors))

        # Write log file after the tee context exits
        log_path.write_text(log_buf.getvalue(), encoding='utf-8')

    # ── Final Report ──────────────────────────────────────────────────────────
    _section('Final Report')
    n_success = sum(1 for r in report if r[4] is not None and not r[6])
    n_partial  = sum(1 for r in report if r[4] is not None and r[6])
    n_failed   = sum(1 for r in report if r[4] is None)

    print(f'Person:       {args.person_name}')
    print(f'Excel:        {excel_path}')
    print(f'CRs found:    {len(cr_list)}')
    print(f'TSs updated:  {n_success} fully OK, {n_partial} with warnings, {n_failed} failed')
    print()

    for ts_key, n_ok, n_skip, n_crs, out_path, log_path, errors in report:
        if out_path and not errors:
            status = 'OK'
        elif out_path:
            status = 'WARN'
        else:
            status = 'FAIL'
        print(f'  [{status}] {ts_key}')
        print(f'         CRs: {n_crs}  |  Body changes applied: {n_ok}  |  Skipped: {n_skip}')
        if out_path:
            print(f'         Output: {out_path.parent.name}/{out_path.name}')
        if log_path and log_path.exists():
            print(f'         Log:    {log_path.parent.name}/{log_path.name}')
        for err in errors:
            print(f'         ! {err}')

    print()
    print(f'Output directory: {output_dir}/')


if __name__ == '__main__':
    main()