"""SQLite update fixture with HTTP-like outcomes, not an HTTP server/parser."""
import json
import re
import sqlite3
from pathlib import Path

ROOT = Path(__file__).parent
db = sqlite3.connect(':memory:', isolation_level=None)
db.execute('CREATE TABLE document (id TEXT PRIMARY KEY, title TEXT, revision INTEGER)')
db.execute("INSERT INTO document VALUES ('d1', 'Original', 1)")
snapshots = [db.execute("SELECT revision FROM document WHERE id='d1'").fetchone()[0] for _ in range(2)]
# Both application-level comparisons see the same revision before either write.
assert snapshots == [1,1]
db.execute("UPDATE document SET title='A', revision=revision+1 WHERE id='d1'")
db.execute("UPDATE document SET title='B', revision=revision+1 WHERE id='d1'")
unsafe = db.execute("SELECT title, revision FROM document WHERE id='d1'").fetchone()
assert unsafe == ('B',3)
db.execute("UPDATE document SET title='Original', revision=1 WHERE id='d1'")

def update(resource, header, value):
    if header is None:
        return 428
    if header == '*':
        changed=db.execute('UPDATE document SET title=?, revision=revision+1 WHERE id=?',(value,resource)).rowcount
    else:
        # Fixture accepts one generated tag only, not the full HTTP list grammar.
        match=re.fullmatch(r'"v([1-9][0-9]*)"',header)
        if not match:
            if header.startswith('W/'):
                return 412
            raise ValueError('Input outside the narrow fixture grammar')
        changed=db.execute('UPDATE document SET title=?, revision=revision+1 WHERE id=? AND revision=?',(value,resource,int(match[1]))).rowcount
    return 204 if changed == 1 else 412

cases=[('client A','d1','"v1"','A',204),('stale client B','d1','"v1"','B',412),('weak current tag','d1','W/"v2"','Weak',412),('missing precondition','d1',None,'Missing',428),('wildcard existing','d1','*','Wildcard',204),('wildcard absent','absent','*','No row',412),('reread and merge','d1','"v3"','Reviewed merge',204)]
rows=[]
for label,resource,tag,value,expected in cases:
    status=update(resource,tag,value)
    assert status==expected,(label,status)
    title,revision=db.execute("SELECT title,revision FROM document WHERE id='d1'").fetchone()
    rows.append(dict(case=label,if_match=tag,status=status,title_after=title,revision_after=revision))
assert rows[1]['title_after']=='A' and rows[1]['revision_after']==2
assert rows[-1]['title_after']=='Reviewed merge' and rows[-1]['revision_after']==4
data={'sqlite_version':sqlite3.sqlite_version,'unsafe_final':{'title':unsafe[0],'revision':unsafe[1]},'guarded_cases':rows,'writes':sum(x['status']==204 for x in rows),'rejected':sum(x['status']!=204 for x in rows)}
(ROOT/'results.json').write_text(json.dumps(data,indent=2)+'\n')
print(json.dumps(data,indent=2))