scripts/build_linear_a_validation.py

#!/usr/bin/env python3
"""
Build the Linear A Phonotactics Validation dataset.

Criteria for inclusion:
  1. Both Lang_A and Lang_B have Linear_A_Score >= 0.80
     (open syllable ratio, no clusters, final vowels, CV structure)
  2. Confidence = "certain" (expert-determined, not contested)
  3. Phono_Quality = "strong" (SCA Score >= 0.5, clear phonological similarity)

This produces a gold-standard dataset of proven cognate pairs between
languages whose phonotactics resemble Linear A. Used to validate
cognate detection models before applying them to Linear A.

Input:
  - analysis/typology_linear_a.tsv (Linear A similarity scores per language)
  - data/training/cognate_pairs/cognate_pairs_inherited.parquet (full dataset)
Output:
  - data/training/cognate_pairs/linear_a_phonotactics_validation.parquet
"""
import csv
import sys
from pathlib import Path

if sys.stdout.encoding != 'utf-8':
    sys.stdout.reconfigure(encoding='utf-8')

THRESHOLD = 0.80


def main():
    hf_dir = Path(__file__).parent.parent

    # 1. Load typology scores
    print('Loading Linear A typology scores...')
    lang_scores = {}
    with open(hf_dir / 'analysis' / 'typology_linear_a.tsv', encoding='utf-8') as f:
        for row in csv.DictReader(f, delimiter='\t'):
            lang_scores[row['Language']] = float(row['Linear_A_Score'])

    qualified_langs = {l for l, s in lang_scores.items() if s >= THRESHOLD}
    print(f'  Languages with score >= {THRESHOLD}: {len(qualified_langs)}')

    # 2. Load full Parquet
    import pyarrow as pa
    import pyarrow.parquet as pq
    import pyarrow.compute as pc

    print('Loading full inherited Parquet...')
    table = pq.read_table(
        hf_dir / 'data' / 'training' / 'cognate_pairs' / 'cognate_pairs_inherited.parquet'
    )
    print(f'  Total rows: {table.num_rows:,}')

    # 3. Filter: both languages qualified, certain confidence, strong phono
    print('Filtering...')
    lang_a = table['Lang_A'].to_pylist()
    lang_b = table['Lang_B'].to_pylist()
    conf = table['Confidence'].to_pylist()
    phono = table['Phono_Quality'].to_pylist()

    mask = []
    for i in range(len(lang_a)):
        keep = (
            lang_a[i] in qualified_langs
            and lang_b[i] in qualified_langs
            and conf[i] == 'certain'
            and phono[i] == 'strong'
        )
        mask.append(keep)

    mask_arr = pa.array(mask)
    filtered = table.filter(mask_arr)
    print(f'  Filtered rows: {filtered.num_rows:,}')

    # 4. Add Linear_A_Score columns for both languages
    scores_a = [lang_scores.get(la, 0.0) for la, m in zip(lang_a, mask) if m]
    scores_b = [lang_scores.get(lb, 0.0) for lb, m in zip(lang_b, mask) if m]

    filtered = filtered.append_column(
        'Linear_A_Score_A', pa.array([round(s, 4) for s in scores_a], type=pa.float64())
    )
    filtered = filtered.append_column(
        'Linear_A_Score_B', pa.array([round(s, 4) for s in scores_b], type=pa.float64())
    )

    # 5. Write output
    out_path = hf_dir / 'data' / 'training' / 'cognate_pairs' / 'linear_a_phonotactics_validation.parquet'
    pq.write_table(filtered, str(out_path), compression='zstd', compression_level=3)

    import os
    size = os.path.getsize(out_path)
    print(f'\n  Written to: {out_path}')
    print(f'  Size: {size/1024/1024:.1f} MB')

    # 6. Statistics
    print(f'\n=== VALIDATION DATASET STATISTICS ===')
    print(f'Total pairs: {filtered.num_rows:,}')

    # Unique languages
    langs = set()
    fa = filtered['Lang_A'].to_pylist()
    fb = filtered['Lang_B'].to_pylist()
    for a in fa:
        langs.add(a)
    for b in fb:
        langs.add(b)
    print(f'Unique languages: {len(langs)}')

    # Load family map
    t2 = pq.read_table(str(hf_dir / 'data' / 'training' / 'metadata' / 'languages.parquet'))
    iso_to_family = dict(zip(t2['ISO'].to_pylist(), t2['Family'].to_pylist()))

    # Family distribution
    fam_counts = {}
    for l in langs:
        fam = iso_to_family.get(l, 'unknown')
        fam_counts[fam] = fam_counts.get(fam, 0) + 1
    print(f'\nLanguage families:')
    for fam, c in sorted(fam_counts.items(), key=lambda x: -x[1]):
        print(f'  {fam}: {c}')

    # Source distribution
    sources = filtered['Source'].to_pylist()
    src_counts = {}
    for s in sources:
        src_counts[s] = src_counts.get(s, 0) + 1
    print(f'\nSource distribution:')
    for src, c in sorted(src_counts.items(), key=lambda x: -x[1]):
        print(f'  {src}: {c:,}')

    # Score distribution
    scores = filtered['Score'].to_pylist()
    float_scores = [float(s) for s in scores if s and s != '-1']
    if float_scores:
        print(f'\nSCA Score distribution:')
        print(f'  Min: {min(float_scores):.4f}')
        print(f'  Max: {max(float_scores):.4f}')
        print(f'  Mean: {sum(float_scores)/len(float_scores):.4f}')
        bins = [(0.5, 0.6), (0.6, 0.7), (0.7, 0.8), (0.8, 0.9), (0.9, 1.01)]
        for lo, hi in bins:
            n = sum(1 for s in float_scores if lo <= s < hi)
            print(f'  [{lo:.1f}, {hi:.1f}): {n:,}')

    # Load names for top contributing languages
    iso_to_name = {}
    glot_path = hf_dir / 'data' / 'training' / 'raw' / 'glottolog_cldf' / 'languages.csv'
    with open(glot_path, encoding='utf-8') as f:
        for row in csv.DictReader(f):
            iso = row.get('ISO639P3code', '').strip()
            name = row.get('Name', '').strip()
            if iso and name:
                iso_to_name[iso] = name

    # Top 20 languages by pair count
    lang_pair_counts = {}
    for a, b in zip(fa, fb):
        lang_pair_counts[a] = lang_pair_counts.get(a, 0) + 1
        lang_pair_counts[b] = lang_pair_counts.get(b, 0) + 1
    print(f'\nTop 20 languages by pair count:')
    for lang, c in sorted(lang_pair_counts.items(), key=lambda x: -x[1])[:20]:
        name = iso_to_name.get(lang, '?')
        fam = iso_to_family.get(lang, '?')
        score = lang_scores.get(lang, 0)
        print(f'  {lang} ({name}) - {fam} - LA score {score:.4f} - {c:,} pairs')


if __name__ == '__main__':
    main()