"""Transactionally append a proven-disjoint audited source to a screened release.

Existing parquet shards are hard-linked and never rewritten. Exact scoped-task,
normalized-prompt and declared-lineage overlap require a full rebuild, because
representative selection and held-out propagation would otherwise change old rows.
"""
from __future__ import annotations

import argparse
from collections import Counter
from datetime import datetime, timezone
from itertools import zip_longest
import json
import os
from pathlib import Path
import re
import shutil
import sqlite3

import pyarrow as pa
import pyarrow.parquet as pq
import yaml

import assemble_task_dataset as assembly
from full_curation_common import BASE, ROOT, STAGING
from screen_task_difficulty import DIFFICULTY_SCHEMA, TIERS, render_difficulty_card
from task_difficulty import annotate_difficulty


def dump(path, value):
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(value, ensure_ascii=False, indent=2) + '\n')


def inventory(directory):
    return {str(p.relative_to(directory)): p for p in directory.rglob('*') if p.is_file()}


def verify_release(release, manifest):
    files = inventory(release)
    if set(files) != set(manifest['files']) | {'release_manifest.json'}:
        raise ValueError('Release inventory differs from its audited manifest')
    for name, expected in manifest['files'].items():
        path = files[name]
        if (path.is_symlink() or not path.resolve().is_relative_to(release.resolve())
                or path.stat().st_size != expected['bytes']
                or assembly.digest(path) != expected['sha256']):
            raise ValueError(f'Release checksum/path mismatch: {name}')


def load_source(source, audit_path):
    folder = STAGING / source
    manifest = json.loads((folder / 'manifest.json').read_text())
    audit = json.loads(audit_path.read_text())
    if audit.get('status') != 'passed' or audit.get('source', source) != source:
        raise ValueError(f'A passed audit for {source} is required')
    if not manifest.get('completed') or manifest.get('source') != source or manifest['records'] <= 0:
        raise ValueError('Source manifest is incomplete or empty')
    listed = {s['file'] for s in manifest['shards']}
    if listed != {p.name for p in folder.glob('*.parquet')} or len(listed) != len(manifest['shards']):
        raise ValueError('Source has duplicate, missing or unmanifested shards')
    if sum(s['rows'] for s in manifest['shards']) != manifest['records']:
        raise ValueError('Source manifest row count mismatch')
    return manifest, audit


def index_counts(db, schema='main'):
    # Schema names are internal constants, never caller input.
    values = db.execute(f'SELECT COUNT(*),SUM(eligible>0),SUM(eligible=0),'
                        f'SUM(eligible>0 AND protected=1) FROM {schema}.tasks').fetchone()
    counts = dict(zip(('task_groups', 'eligible_task_groups', 'quarantined_task_groups',
                       'heldout_eligible_task_groups'), (int(v or 0) for v in values)))
    counts['annotation_records'] = db.execute(f'SELECT COUNT(*) FROM {schema}.records').fetchone()[0]
    counts['duplicate_annotation_records'] = counts['annotation_records'] - counts['task_groups']
    counts['cross_source_task_groups'] = db.execute(
        f'SELECT COUNT(*) FROM {schema}.tasks WHERE (sources & (sources-1)) != 0').fetchone()[0]
    return counts


def prove_disjoint(db, prior_index, old_counts, source):
    db.execute('ATTACH DATABASE ? AS prior', (prior_index.resolve().as_uri() + '?mode=ro',))
    try:
        prior_counts = index_counts(db, 'prior')
        if any(old_counts.get(k) != v for k, v in prior_counts.items()):
            raise ValueError('Existing index does not match the release counts; perform a full rebuild')
        if db.execute('SELECT 1 FROM prior.records WHERE id LIKE ? LIMIT 1', (source + ':%',)).fetchone():
            raise ValueError('Source record prefix already exists; perform a full rebuild')
        checks = {
            'scoped_task_id': 'SELECT n.id FROM main.tasks n JOIN prior.tasks p ON p.id=n.id LIMIT 1',
            'normalized_prompt_hash': 'SELECT n.prompt FROM main.tasks n JOIN prior.tasks p ON p.prompt=n.prompt LIMIT 1',
            'declared_lineage': 'SELECT n.lineage FROM main.lineage n JOIN prior.lineage p ON p.lineage=n.lineage LIMIT 1',
        }
        for name, query in checks.items():
            if db.execute(query).fetchone():
                raise ValueError(f'{name} overlaps the existing release; perform a full rebuild')
        return {'status': 'passed', 'prior_index_counts': prior_counts,
                'scoped_task_id_overlaps': 0, 'normalized_prompt_hash_overlaps': 0,
                'declared_lineage_overlaps': 0, 'source_record_prefix_present': False}
    finally:
        db.execute('DETACH DATABASE prior')


class PrefixedShards(assembly.Shards):
    def __init__(self, directory, prefix, schema=DIFFICULTY_SCHEMA):
        super().__init__(directory, schema=schema)
        self.prefix = prefix

    def flush(self):
        if not self.buffer:
            return
        path = self.directory / f'{self.prefix}-part-{len(self.files):05d}.parquet'
        if path.exists():
            raise ValueError(f'Append would overwrite an existing shard: {path}')
        pq.write_table(pa.Table.from_pylist(self.buffer, schema=self.schema), path,
                       compression='zstd', row_group_size=500)
        self.files.append({'file': str(path), 'rows': len(self.buffer),
                           'bytes': path.stat().st_size, 'sha256': assembly.digest(path)})
        self.buffer.clear()


def relative_config(writer, release):
    config = writer.close()
    for shard in config['shards']:
        shard['file'] = str(Path(shard['file']).relative_to(release))
    return config


def add_config(configs, name, addition):
    config = configs.setdefault(name, {'rows': 0, 'shards': []})
    config['rows'] += addition['rows']
    config['shards'].extend(addition['shards'])


def export_source(working, source, manifest, db):
    source_writer = assembly.Shards(working / 'data' / source)
    quarantine = assembly.Shards(working / 'data/quarantine' / source)
    tiers = {tier: PrefixedShards(working / 'data/tasks' / tier, source) for tier in TIERS}
    families, leaves, counts, evidence, samples = Counter(), Counter(), Counter(), Counter(), {}
    annotation_tiers, eligible_annotation_tiers, annotation_evidence = Counter(), Counter(), Counter()
    for shard in manifest['shards']:
        path = STAGING / source / shard['file']
        for batch in pq.ParquetFile(path).iter_batches(batch_size=256):
            rows = batch.to_pylist()
            keys = sorted({assembly.scoped_task_id(r) for r in rows})
            matches = db.execute('SELECT id,representative,annotations,eligible,protected,training '
                                 'FROM tasks WHERE id IN (' + ','.join('?' for _ in keys) + ')', keys)
            groups = {r[0]: r[1:] for r in matches}
            for row in rows:
                original_id = row['task_id']
                task_id = assembly.scoped_task_id(row)
                representative, annotations, eligible, protected, training = groups[task_id]
                reasons = assembly.classification(row)
                row.update(task_id=task_id, prompt_context_id=original_id,
                           annotation_count=annotations, eligible_annotation_count=eligible,
                           group_sources=[source], source_split_status='held_out' if protected else ('source_train' if training else 'unspecified'),
                           curation_status='quarantined' if reasons else 'curated_candidate', curation_reasons=reasons)
                labels = annotate_difficulty(row)
                if set(labels) != set(DIFFICULTY_SCHEMA.names) - set(assembly.RELEASE_SCHEMA.names) or labels['difficulty_tier'] not in TIERS:
                    raise ValueError('Difficulty classifier returned an invalid annotation')
                annotation_tiers[labels['difficulty_tier']] += 1
                if not reasons:
                    eligible_annotation_tiers[labels['difficulty_tier']] += 1
                if labels['difficulty_tier'] != 'uncalibrated':
                    annotation_evidence.update(labels['difficulty_evidence'])
                source_writer.add(row.copy())
                if reasons:
                    quarantine.add(row.copy())
                if eligible and row['record_id'] == representative:
                    row.update(labels)
                    tier = labels['difficulty_tier']
                    tiers[tier].add(row)
                    counts[tier] += 1; evidence.update(labels['difficulty_evidence'])
                    families[row['family']] += 1; leaves[row['leaf'] or 'unassigned'] += 1
                    sample_key = source + ':' + tier
                    if len(samples.setdefault(sample_key, [])) < 3:
                        samples[sample_key].append({'record_id': row['record_id'], 'prompt_excerpt': row['prompt'][:400],
                                                    'evidence': labels['difficulty_evidence']})
        # Ensure source staging stayed unchanged between indexing and export.
        if path.stat().st_size != shard['bytes'] or assembly.digest(path) != shard['sha256']:
            raise ValueError(f'Source changed during append: {shard["file"]}')
    return {'source': relative_config(source_writer, working), 'quarantine': relative_config(quarantine, working),
            'tiers': {k: relative_config(v, working) for k, v in tiers.items()},
            'families': families, 'leaves': leaves, 'counts': counts,
            'evidence': evidence, 'samples': samples,
            'annotation_difficulty': {'annotations': dict(annotation_tiers), 'eligible_annotations': dict(eligible_annotation_tiers),
                                      'tier_evidence_counts': dict(annotation_evidence)}}


def merge_index(prior_path, added_path, combined_path, source, expected_counts):
    prior = sqlite3.connect(prior_path.resolve().as_uri() + '?mode=ro', uri=True)
    combined = sqlite3.connect(combined_path)
    try:
        prior.backup(combined)
        combined.execute('ATTACH DATABASE ? AS added', (added_path.resolve().as_uri() + '?mode=ro',))
        bit = 1 << assembly.SOURCE_NAMES.index(source)
        with combined:
            combined.execute('INSERT INTO records SELECT * FROM added.records')
            combined.execute('INSERT INTO tasks SELECT id,representative,rank,annotations,eligible,?,protected,training,prompt FROM added.tasks', (bit,))
            combined.execute('INSERT INTO lineage SELECT * FROM added.lineage')
            combined.execute('INSERT OR IGNORE INTO heldout_prompts SELECT * FROM added.heldout_prompts')
        if any(expected_counts.get(k) != v for k, v in index_counts(combined).items()):
            raise ValueError('Combined index count mismatch')
        if combined.execute('PRAGMA quick_check').fetchone()[0] != 'ok':
            raise ValueError('Combined index integrity check failed')
    finally:
        combined.close(); prior.close()


def copy_source_notices(working, manifest):
    """Copy declared README/license artifacts only after checking their hashes."""
    entries = [entry for entry in manifest.get('auxiliary_input_files', [])
               if 'README' in Path(entry['file']).name.upper()
               or Path(entry['file']).name.upper().startswith(('LICENSE', 'NOTICE', 'COPYING'))]
    if not entries:
        return
    repos = {manifest['source_repo']} | {entry['repo'] for entry in entries}
    candidates = []
    for repo in repos:
        for separator in ('--', '__'):
            folder = BASE / 'downloads' / repo.replace('/', separator)
            if folder.exists():
                candidates.extend(p for p in folder.rglob('*') if p.is_file()
                                  and ('README' in p.name.upper() or p.name.upper().startswith(('LICENSE', 'NOTICE', 'COPYING'))))
    target = working / 'source_notices/upstream' / manifest['source_repo'].replace('/', '__')
    target.mkdir(parents=True, exist_ok=True)
    notices = []
    for entry in entries:
        matches = [p for p in candidates if p.stat().st_size == entry['bytes'] and assembly.digest(p) == entry['sha256']]
        if not matches:
            raise ValueError(f"Declared source notice is missing or changed: {entry['repo']}:{entry['file']}")
        name = entry['repo'].replace('/', '__') + '__' + Path(entry['file']).name
        destination = target / name
        shutil.copyfile(matches[0], destination)
        notices.append(dict(entry, bundled_file=str(destination.relative_to(working))))
    dump(target / 'notice_manifest.json', notices)


def update_documents(working, source, manifest, audit_path, quality, difficulty, inventory_manifest):
    dump(working / 'manifests' / f'{source}.json', manifest)
    shutil.copyfile(audit_path, working / 'audit' / audit_path.name)
    shutil.copyfile(audit_path, working / 'curation/outputs/full_curation' / audit_path.name)
    metadata_path = BASE / 'source_metadata.json'
    all_metadata = json.loads(metadata_path.read_text())
    matching = [m for m in all_metadata if m['repo'] == manifest['source_repo'] and m['sha'] == manifest['revision']]
    if len(matching) != 1:
        raise ValueError('Pinned source metadata is missing or ambiguous')
    public_metadata_path = working / 'manifests/source_metadata.json'
    public_metadata = json.loads(public_metadata_path.read_text())
    public_metadata.append({k: matching[0][k] for k in ('repo', 'sha', 'license', 'files') if k in matching[0]})
    dump(public_metadata_path, public_metadata)
    shutil.copyfile(metadata_path, working / 'curation/outputs/full_curation/source_metadata.json')
    repo, revision = manifest['source_repo'], manifest['revision']
    url = f'https://github.com/{repo[7:]}/tree/{revision}' if repo.startswith('github:') else f'https://huggingface.co/datasets/{repo}/tree/{revision}'
    with (working / 'LICENSES.md').open('a') as out:
        out.write(f'\n## {source}\n\nDeclared license: {manifest["license"]}\n\nPinned source: {url}\n\nPer-record attribution and upstream article/component terms remain applicable.\n')
    (working / 'source_notices' / f'{source}.md').write_text(f'# {source}\n\nPinned source: {url}\n\nDeclared source license: {manifest["license"]}\n\nPer-record attribution and upstream component licenses are retained.\n')
    copy_source_notices(working, manifest)
    manifests = {name: json.loads((working / 'manifests' / f'{name}.json').read_text()) for name in quality['sources']}
    if set(manifests) != set(assembly.SOURCE_NAMES):
        raise ValueError('Source registry differs from release sources; perform a full rebuild')
    (working / 'README.md').write_text(assembly.render_card(quality, manifests))
    render_difficulty_card(working, difficulty)
    card = working / 'README.md'
    _, header, body = card.read_text().split('---', 2)
    card_meta = yaml.safe_load(header)
    for config in card_meta['configs']:
        if config['config_name'] == 'quarantine':
            config['data_files'][0]['path'] = 'data/quarantine/**/*.parquet'
        patterns = config['data_files'][0]['path']
        patterns = [patterns] if isinstance(patterns, str) else patterns
        matched = {str(p.relative_to(working)) for pattern in patterns for p in working.glob(pattern)}
        listed = {s['file'] for s in inventory_manifest['configs'][config['config_name']]['shards']}
        if matched != listed:
            raise ValueError(f'Card paths disagree with manifest: {config["config_name"]}')
    card.write_text('---\n' + yaml.safe_dump(card_meta, sort_keys=False) + '---\n' + body.lstrip())
    adapters = sorted((ROOT / 'scripts').glob(f'curate*{source}*.py'))
    if len(adapters) != 1:
        raise ValueError(f'Expected one reproducible adapter for {source}, found {len(adapters)}')
    scripts = [Path(__file__), ROOT / 'scripts/assemble_task_dataset.py', ROOT / 'scripts/publish_task_dataset.py', ROOT / 'scripts/screen_task_difficulty.py',
               ROOT / 'scripts/task_difficulty.py', *adapters, *sorted((ROOT / 'scripts').glob(f'audit*{source}*.py'))]
    for path in scripts:
        shutil.copyfile(path, working / 'curation/scripts' / path.name)
    shutil.copyfile(ROOT / 'pyproject.toml', working / 'curation/pyproject.toml')
    reproduction = working / 'curation/README.md'
    text = reproduction.read_text()
    command = f'.venv/bin/python scripts/{adapters[0].name}\n'
    if command not in text:
        text = text.replace('.venv/bin/python scripts/assemble_task_dataset.py\n', command + '.venv/bin/python scripts/assemble_task_dataset.py\n')
    reproduction.write_text(text)


def install_pair(release, working, release_backup, index, combined, index_backup):
    moved_release = moved_index = installed_release = installed_index = False
    try:
        release.rename(release_backup); moved_release = True
        index.rename(index_backup); moved_index = True
        working.rename(release); installed_release = True
        combined.rename(index); installed_index = True
    except BaseException:
        if installed_index:
            index.rename(combined)
        if installed_release:
            release.rename(working)
        if moved_index:
            index_backup.rename(index)
        if moved_release:
            release_backup.rename(release)
        raise


def append_source(source, release, prior_index=None, audit_path=None):
    if not re.fullmatch(r'[a-z0-9_]+', source) or source not in assembly.SOURCE_NAMES:
        raise ValueError('Source must be registered in SOURCE_NAMES')
    prior_index = prior_index or BASE / 'curation_index.sqlite'
    audit_path = audit_path or BASE / f'audit_{source}_sources.json'
    working = release.with_name(release.name + f'.append-{source}-build')
    release_backup = release.with_name(release.name + f'_before_{source}')
    new_index = BASE / f'append_{source}_index.sqlite'
    combined = prior_index.with_name(prior_index.name + f'.append-{source}-build')
    index_backup = prior_index.with_name(prior_index.name + f'.before-{source}')
    for path in (working, release_backup, new_index, combined, index_backup):
        if path.exists():
            raise ValueError(f'An append artifact already exists; inspect before retrying: {path}')
    old = json.loads((release / 'release_manifest.json').read_text())
    quality = json.loads((release / 'audit/quality_report.json').read_text())
    difficulty = json.loads((release / 'audit/difficulty_report.json').read_text())
    if source in old['configs'] or (release / 'data' / source).exists():
        raise ValueError('Source already belongs to this release; perform a full rebuild')
    if quality.get('status') != 'passed' or difficulty.get('status') != 'passed' or quality['counts'] != old['counts']:
        raise ValueError('A complete audited and difficulty-screened release is required')
    if tuple(quality['sources']) != tuple(s for s in assembly.SOURCE_NAMES if s != source) or assembly.SOURCE_NAMES[-1] != source:
        raise ValueError('Source must extend the existing ordered registry; perform a full rebuild')
    verify_release(release, old)
    prior_manifest_digest = assembly.digest(release / 'release_manifest.json')
    prior_index_digest = assembly.digest(prior_index)
    source_manifest, source_audit = load_source(source, audit_path)
    db, new_stats, new_counts = assembly.build_index({source: source_manifest}, new_index)
    try:
        proof = prove_disjoint(db, prior_index, old['counts'], source)
        proof.update(source=source, previous_release_manifest_sha256=prior_manifest_digest,
                     previous_index_sha256=prior_index_digest, source_audit_sha256=assembly.digest(audit_path),
                     source_manifest_sha256=assembly.digest(STAGING / source / 'manifest.json'))
        def clone_file(src, dst):
            if Path(src).suffix == '.parquet':
                os.link(src, dst)
                return dst
            return shutil.copy2(src, dst)
        shutil.copytree(release, working, copy_function=clone_file)
        added = export_source(working, source, source_manifest, db)
        if (added['source']['rows'] != new_counts['annotation_records']
                or sum(added['counts'].values()) != new_counts['eligible_task_groups']
                or added['quarantine']['rows'] != new_stats[source]['quarantined_annotations']):
            raise ValueError('New source export counts differ from its index')
    finally:
        db.close()
    counts = old['counts']
    for key, value in new_counts.items():
        if key == 'heldout_propagation_rounds':
            counts[key] = [a + b for a, b in zip_longest(counts.get(key, []), value, fillvalue=0)]
        else:
            counts[key] = counts.get(key, 0) + value
    tier_counts = {tier: difficulty['difficulty_tiers'].get(tier, 0) + added['counts'][tier] for tier in TIERS}
    counts['difficulty_tiers'] = dict(tier_counts)
    counts['qwen_core_task_groups'] = tier_counts['core_candidate'] + tier_counts['uncalibrated']
    old['configs'][source] = added['source']
    add_config(old['configs'], 'quarantine', added['quarantine'])
    for tier, config in added['tiers'].items():
        add_config(old['configs'], 'tasks', config)
        add_config(old['configs'], 'foundational' if tier == 'foundational' else 'qwen_core', config)
    now = datetime.now(timezone.utc).isoformat()
    difficulty.update(generated_at=now, unique_tasks_screened=counts['eligible_task_groups'],
                      difficulty_tiers=dict(tier_counts), qwen_core_task_groups=counts['qwen_core_task_groups'])
    difficulty['source_counts'][source] = dict(added['counts'])
    difficulty['evidence_counts'] = dict(Counter(difficulty['evidence_counts']) + added['evidence'])
    difficulty['illustrative_samples'].update(added['samples'])
    quality.update(generated_at=now, counts=counts)
    quality['sources'].update(new_stats)
    quality['task_families'] = dict(Counter(quality['task_families']) + added['families'])
    quality['task_leaves'] = dict(Counter(quality['task_leaves']) + added['leaves'])
    quality['difficulty_screen'] = {k: difficulty[k] for k in ('target_model', 'difficulty_tiers', 'qwen_core_task_groups', 'empirical_difficulty_measured')}
    quality['checks'].extend(['incremental_source_disjoint_task_prompt_lineage_proof', 'prior_parquet_shards_preserved'])
    proof.update(generated_at=now, new_source_counts=new_counts, difficulty_tiers=dict(added['counts']),
                 full_source_annotations_preserved=True, empirical_difficulty_measured=False)
    dump(working / 'audit' / f'append_{source}_report.json', proof)
    dump(working / 'audit/quality_report.json', quality)
    dump(working / 'audit/difficulty_report.json', difficulty)
    source_difficulty_path = working / 'audit/audit_difficulty_sources.json'
    if source_difficulty_path.exists():
        source_difficulty = json.loads(source_difficulty_path.read_text())
        source_difficulty['sources'][source] = added['annotation_difficulty']
        dump(source_difficulty_path, source_difficulty)
    update_documents(working, source, source_manifest, audit_path, quality, difficulty, old)
    merge_index(prior_index, new_index, combined, source, counts)
    final_files = {name: {'bytes': p.stat().st_size, 'sha256': assembly.digest(p)}
                   for name, p in sorted(inventory(working).items()) if name != 'release_manifest.json'}
    for name, entry in old['files'].items():
        if name.endswith('.parquet') and final_files.get(name) != entry:
            raise ValueError(f'Prior parquet shard changed during append: {name}')
    if assembly.digest(prior_index) != prior_index_digest or assembly.digest(release / 'release_manifest.json') != prior_manifest_digest:
        raise ValueError('Original release or index changed concurrently; append aborted')
    old['files'] = final_files
    dump(working / 'release_manifest.json', old)
    install_pair(release, working, release_backup, prior_index, combined, index_backup)
    print(json.dumps({'status': 'passed', 'source': source, 'appended_source_counts': new_counts,
                      'release_counts': counts, 'prior_parquet_shards_unchanged': True}, indent=2), flush=True)
    return proof


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--source', required=True)
    parser.add_argument('--release', type=Path, default=BASE / 'release')
    parser.add_argument('--index', type=Path)
    parser.add_argument('--audit', type=Path)
    args = parser.parse_args()
    append_source(args.source, args.release, args.index, args.audit)


if __name__ == '__main__':
    main()