"""V4.4 ablation-arm pretraining entry point; W&B without any machine-wide login.

Credentials come only from the environment (WANDB_API_KEY, optional WANDB_ENTITY),
as `cluster_v44.sh` sets them from a private file with isolated W&B directories.
Without a key, or when online initialization fails, the run logs offline under
artifacts/tracking/<model>/ for a later `wandb sync`; training never waits on W&B.
"""
import argparse
import os
from pathlib import Path
import sys
import tomllib
ROOT=Path(__file__).resolve().parents[2]
sys.path.insert(0,str(ROOT/'src'))


def main():
    parser=argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--config',type=Path,required=True)
    parser.add_argument('--resume',action='store_true')
    parser.add_argument('--dry-run',action='store_true',
        help='Verify configuration, code and data identities, then exit')
    args=parser.parse_args()
    config=tomllib.loads(args.config.read_text('utf-8'))
    output=ROOT/config['output_dir']
    logs=ROOT/config['log_dir']
    if args.dry_run:
        from vimeml.training.joint_v44 import build_plan
        plan=build_plan(config,ROOT,verify_files=True)
        print({'stage':plan['stage'],'arm':config['arm'],'parameters':plan['parameters'],
               'max_steps':plan['settings']['max_steps'],
               'updates_per_epoch':plan['settings']['updates_per_epoch'][:3]+['...'],
               'required_files':len(plan['required_files'])})
        return
    if not args.resume and ((output.exists() and any(output.iterdir())) or (logs.exists() and any(logs.iterdir()))):
        parser.error('Fresh V4.4 output/log directories must be empty')
    if args.resume and not (output/'last.pt').exists():
        parser.error('No V4.4 checkpoint to resume')
    from vimeml.training.joint_v44 import run
    tracking=config.get('tracking',{})
    if not tracking.get('enabled'):
        result=run(config,args.resume)
        print(result,flush=True)
        return
    import wandb
    from vimeml.training.data import write_json
    directory=ROOT/'artifacts/tracking'/output.name
    directory.mkdir(parents=True,exist_ok=True)
    def start(mode):
        return wandb.init(project=tracking.get('project','vimeml'),entity=os.environ.get('WANDB_ENTITY'),
            group=tracking['group'],name=config['arm']+('-resume' if args.resume else ''),
            job_type='pretraining',tags=['v4.4',config['arm']],mode=mode,dir=str(directory),
            sync_tensorboard=True,save_code=False,config=config,
            settings=wandb.Settings(disable_git=True,init_timeout=90))
    mode=tracking.get('mode','online') if os.environ.get('WANDB_API_KEY') else 'offline'
    try:
        cloud=start(mode)
    except Exception as error:
        if mode=='offline':
            raise
        print(f'W&B online initialization failed ({type(error).__name__}: {error}); logging offline',flush=True)
        mode='offline'
        cloud=start(mode)
    with cloud:
        write_json(directory/f'live-{cloud.id}.json',{'id':cloud.id,'url':cloud.url if mode!='offline' else None,
            'mode':mode,'resume':args.resume,'directory':str(directory)})
        print(f'W&B run ({mode}): {cloud.url if mode!="offline" else directory}',flush=True)
        result=run(config,args.resume)
        cloud.summary.update({'training_result':result})


if __name__=='__main__':
    main()