"""Dry-run execution for planned GPU task manifests."""

from __future__ import annotations

import json
from pathlib import Path
from typing import Any

from zsgdp.gpu.batching import batch_gpu_tasks
from zsgdp.gpu.runtime import collect_gpu_runtime_status
from zsgdp.gpu.worker import GPUWorker
from zsgdp.utils import write_json


def load_gpu_tasks(path: str | Path) -> list[dict[str, Any]]:
    task_path = _task_manifest_path(path)
    if not task_path.exists():
        raise FileNotFoundError(f"Missing GPU task manifest: {task_path}")
    return [
        json.loads(line)
        for line in task_path.read_text(encoding="utf-8").splitlines()
        if line.strip()
    ]


def run_gpu_task_manifest(
    input_path: str | Path,
    *,
    config: dict[str, Any],
    output_path: str | Path | None = None,
    dry_run: bool = True,
) -> dict[str, Any]:
    tasks = load_gpu_tasks(input_path)
    report = dry_run_gpu_tasks(tasks, config=config, dry_run=dry_run)
    if output_path is not None:
        write_json(output_path, report)
    return report


def dry_run_gpu_tasks(
    tasks: list[dict[str, Any]],
    *,
    config: dict[str, Any],
    dry_run: bool = True,
    runtime_status: dict[str, Any] | None = None,
) -> dict[str, Any]:
    runtime = runtime_status or collect_gpu_runtime_status(config).to_dict()
    max_batch_size = int(config.get("gpu", {}).get("max_batch_size", runtime.get("max_batch_size", 4)))
    batches = batch_gpu_tasks(tasks, max_batch_size=max_batch_size)
    worker = GPUWorker(config)
    batch_results = [worker.run_batch(batch, dry_run=dry_run) for batch in batches]

    ready_count = sum(result["ready_count"] for result in batch_results)
    blocked_count = sum(result["blocked_count"] for result in batch_results)
    executed_count = sum(result.get("executed_count", 0) for result in batch_results)
    failed_count = sum(result.get("failed_count", 0) for result in batch_results)
    report = {
        "dry_run": dry_run,
        "task_count": len(tasks),
        "batch_count": len(batches),
        "ready_count": ready_count,
        "blocked_count": blocked_count,
        "executed_count": executed_count,
        "failed_count": failed_count,
        "runtime": runtime,
        "batches": batch_results,
    }
    return report


def _task_manifest_path(path: str | Path) -> Path:
    path_obj = Path(path)
    if path_obj.is_dir():
        return path_obj / "gpu_tasks.jsonl"
    return path_obj