#!/usr/bin/env python3
"""Build only from a fresh temporary copy; publish output only on success."""
from pathlib import Path
import datetime, os, re, shutil, subprocess, tempfile

ROOT = Path(__file__).resolve().parents[1]
SOURCE = ROOT / 'latex-manual'
OUT = ROOT / 'build' / 'manual'

def run(args, cwd=ROOT):
    print('+ ' + ' '.join(args), flush=True)
    subprocess.run(args, cwd=cwd, check=True)

def git(*args):
    return subprocess.check_output(['git', *args], cwd=ROOT, text=True).strip()

def main():
    OUT.mkdir(parents=True, exist_ok=True)
    # Only remove this script's two fixed output files, so a failed run cannot
    # leave a stale deliverable looking successful.
    for name in ('SmartPark-Manual.pdf', 'build-info.txt'):
        (OUT / name).unlink(missing_ok=True)
    sha = git('rev-parse', 'HEAD')
    expected = os.environ.get('MANUAL_COMMIT', '')
    ci = os.environ.get('MANUAL_CI', '') == 'true'
    dirty = bool(git('status', '--porcelain', '--untracked-files=normal'))
    if ci and (not expected or expected != sha or dirty):
        raise RuntimeError('CI checkout must be clean and match MANUAL_COMMIT')
    number = os.environ.get('MANUAL_RUN_NUMBER', 'local')
    if ci and not number.isdigit():
        raise RuntimeError('Missing numeric Gitea run number')
    if not re.fullmatch(r'[A-Za-z0-9.-]+', number):
        raise RuntimeError('Unsafe run identifier')
    revision = sha[:12] + ('-dirty' if dirty else '')
    build_time = datetime.datetime.now(datetime.timezone.utc).strftime('%Y-%m-%d %H:%M UTC')
    for tool in ('latexmk', 'pdflatex', 'bibtex', 'makeglossaries', 'makeindex', 'pygmentize'):
        if shutil.which(tool) is None:
            raise RuntimeError('Missing tool: ' + tool)
    with tempfile.TemporaryDirectory(prefix='manual-', dir=ROOT / 'build') as temp:
        work = Path(temp)
        shutil.copytree(SOURCE, work, dirs_exist_ok=True,
                        ignore=shutil.ignore_patterns('*.aux', '*.log', '*.pdf', '*.toc', '*.out',
                            '*.bbl', '*.blg', '*.fdb_latexmk', '*.fls', '*.idx', '*.ind', '*.ilg',
                            '*.glo', '*.gls', '*.glg', '*.ist', '*.acn', '*.acr', '*.alg',
                            '*.lof', '*.lot', '_minted-*', 'build-metadata.tex'))
        # Do not discard legitimate PDF figures: restore tracked/source PDFs
        # except the old root document output.
        for source_pdf in SOURCE.rglob('*.pdf'):
            if source_pdf == SOURCE / 'devopsAssignment.pdf':
                continue
            target = work / source_pdf.relative_to(SOURCE)
            target.parent.mkdir(parents=True, exist_ok=True)
            shutil.copy2(source_pdf, target)
        (work / 'build-metadata.tex').write_text(
            '\\renewcommand{\\BuildRevision}{' + revision + '}\n' +
            '\\renewcommand{\\BuildRun}{' + number + '}\n' +
            '\\renewcommand{\\BuildUTC}{' + build_time + '}\n', encoding='utf-8')
        command = ['latexmk', '-pdf', '-interaction=nonstopmode', '-halt-on-error',
                   '-file-line-error', '-shell-escape', 'devopsAssignment.tex']
        run(command, work)
        run(['makeglossaries', 'devopsAssignment'], work)
        if (work / 'devopsAssignment.idx').stat().st_size:
            run(['makeindex', 'devopsAssignment.idx'], work)
        run(command, work)
        pdf = work / 'devopsAssignment.pdf'
        if not pdf.is_file() or pdf.stat().st_size < 5 or pdf.read_bytes()[:5] != b'%PDF-':
            raise RuntimeError('Expected nonempty PDF was not produced')
        log = (work / 'devopsAssignment.log').read_text(errors='replace')
        if 'There were undefined references' in log or 'There were undefined citations' in log:
            raise RuntimeError('PDF still contains unresolved references/citations; inspect source')
        shutil.copy2(pdf, OUT / 'SmartPark-Manual.pdf')
        info = f'commit={sha}\nrevision={revision}\nrun={number}\nutc={build_time}\n'
        info += 'mode=' + ('Gitea Actions' if ci else 'LOCAL TEST - not Actions evidence') + '\n'
        for tool, flag in [('latexmk','-v'), ('pdflatex','--version'), ('pygmentize','-V')]:
            result = subprocess.check_output([tool, flag], text=True)
            info += result
        packages = subprocess.check_output(['dpkg-query', '-W',
            '-f=${Package}\t${Version}\n', 'latexmk', 'texlive-base',
            'texlive-latex-extra', 'texlive-fonts-recommended', 'lmodern', 'python3-pygments'], text=True)
        info += '\nUbuntu package versions:\n' + packages
        (OUT / 'build-info.txt').write_text(info, encoding='utf-8')
        print(info)
        print('SUCCESS: ' + str(OUT / 'SmartPark-Manual.pdf'))

if __name__ == '__main__':
    main()