"""Bounded generation recovery; raw drafts remain available for inspection."""
import copy,re
from collections import Counter

def repetition(text):
    words=re.findall(r"\w+",text.casefold())
    tail=words[-100:]
    for n in (3,4,5,6):
        grams=[tuple(tail[i:i+n]) for i in range(len(tail)-n+1)]
        if grams and max(Counter(grams).values())>=4:return True
    compact=re.sub(r"\s+","",text)[-240:]
    return bool(re.search(r"(.{2,20})\1{5,}",compact))

def sentence_end(text):
    return bool(re.search(r'[.!?。！？؟]["”’\')\]]*$',text.strip()))

def complete_prefix(text):
    # Keep only complete sentences before repetitive material starts.
    out=''
    for m in re.finditer(r'[\s\S]*?[.!?。！？؟](?:["”’\')\]]*)(?=\s|$)',text):
        candidate=text[:m.end()].strip()
        if repetition(candidate):break
        out=candidate
    return out

def rewrite(original,generate,geometry,local,cancel,progress,max_chars=None):
    attempts=[];limit=max_chars if max_chars is not None else 2*len(original)
    for number in range(1):
        if cancel.is_set():break
        g=copy.deepcopy(geometry)
        progress('Generating with requested steering settings…')
        try:r=generate(g,number)
        except Exception as error:
            if cancel.is_set():raise InterruptedError('Stopped; completed passages saved.') from error
            attempts.append({'error':str(error),'attempt':number+1});break
        raw=r['text'];r['attempt']=number+1;r['effective_controls']=g['controls'] if local else None
        issues=[]
        if repetition(raw):issues.append('repetition')
        if not sentence_end(raw):issues.append('unfinished ending')
        if not raw.strip():issues.append('empty output')
        if len(raw)>limit:issues.append('length limit')
        r['quality_issues']=issues;attempts.append(r)
        if not issues:
            return {**r,'attempts':attempts,'selected_attempt':number+1,'recovery':number>0}
        if cancel.is_set():break
    # Never join a chopped word to the next passage. Preserve raw drafts in attempts.
    for r in reversed(attempts):
        prefix=complete_prefix(r.get('text','')[:limit])
        if prefix:
            return {**r,'text':prefix,'attempts':attempts,'selected_attempt':r['attempt'],'warning':'Only complete sentences retained; inspect raw attempts for omitted material.','recovery':True}
    return {'text':original,'attempts':attempts,'original_retained':True,'error':'No complete non-repetitive draft; original retained. Raw attempts are in the report.'}