"""In-process driver for the zynq-imx6-flow LangGraph workflow.

Builds the compiled graph from the project's ``app`` package and drives it with a
persistent SqliteSaver — no ``langgraph dev`` server. Mirrors the sibling
fpga-imx6-flow driver: exit code 0 = done, 1 = error, 2 = interrupt fired.

Commands:
    start   --project-dir <dir> [--program-mode bitstream|debug_flash]
            [--ps-mode baremetal|petalinux] [--board-type xmod|zynq_only]
            [--bit-path ..] [--elf-path ..] [--flash-path ..]
            [--thread-id ..] [--real] [--max-iterations N]
    resume  --project-dir <dir> --resume-json '<json>' [--thread-id ..] [--real]
    status  --project-dir <dir> [--thread-id ..]

Output: one JSON line on stdout describing status + the pending interrupt(s).

Resume payloads:
  * Single pending interrupt  -> pass its payload directly, e.g. '{"meets": true}'.
  * Multiple pending (the three-way modify fan-out: modify_fpga + modify_imx6 +
    modify_ps can fire in one superstep) -> pass a map keyed by each interrupt's
    "action", e.g. '{"modify_fpga": {...}, "modify_imx6": {...}, "modify_ps": {...}}'.
    You may resume a subset; unresumed interrupts stay pending and round_done
    (defer=True) still waits for every active branch.

Run via the env python directly or ``conda run --no-capture-output`` to avoid the
Windows GBK console re-encode crash on the Chinese interrupt payloads.
"""
from __future__ import annotations

import argparse
import json
import os
import re
import sys
from pathlib import Path

try:
    sys.stdout.reconfigure(encoding="utf-8")  # emit UTF-8 even on a GBK console
except Exception:
    pass


def _env_lookup(key: str, default: str | None = None) -> str | None:
    """Read KEY from the OS environment, else from a ``KEY = value`` line in
    ~/skills_env.md. Machine-local paths are never hardcoded in a skill; see
    the same helper in fpga_flash/scripts/vivado_env.py."""
    value = os.environ.get(key)
    if value:
        return value
    path = os.path.join(os.path.expanduser("~"), "skills_env.md")
    try:
        with open(path, encoding="utf-8") as handle:
            for line in handle:
                match = re.match(rf"\s*{re.escape(key)}\s*=\s*(.+?)\s*(?:#.*)?$", line)
                if match:
                    found = match.group(1).strip()
                    if found and not found.startswith("<"):
                        return found
    except OSError:
        pass
    return default


#: The zynq-imx6-flow checkout: ZYNQ_IMX6_FLOW_ROOT in ~/skills_env.md.
DEFAULT_PROJECT = _env_lookup("ZYNQ_IMX6_FLOW_ROOT")


def _emit(obj: dict, code: int) -> None:
    print(json.dumps(obj, ensure_ascii=False))
    sys.exit(code)


def _pending(snap):
    return [intr for task in snap.tasks for intr in task.interrupts]


def main() -> None:
    ap = argparse.ArgumentParser(description="Drive the zynq-imx6-flow graph in-process.")
    ap.add_argument("command", choices=["start", "resume", "status"])
    ap.add_argument("--project-dir", default=DEFAULT_PROJECT)
    ap.add_argument("--thread-id", default="zynq-skill-1")
    ap.add_argument("--resume-json", default="")
    ap.add_argument("--program-mode", default="bitstream",
                    choices=["bitstream", "debug_flash"])
    ap.add_argument("--ps-mode", default="baremetal", choices=["baremetal", "petalinux"])
    ap.add_argument("--board-type", default="xmod", choices=["xmod", "zynq_only"])
    ap.add_argument("--bit-path", default="")
    ap.add_argument("--elf-path", default="")
    ap.add_argument("--flash-path", default="")
    ap.add_argument("--real", action="store_true",
                    help="drive real hardware (tools_* must be wired; default is MOCK dry-run)")
    ap.add_argument("--max-iterations", type=int, default=8)
    args = ap.parse_args()

    if not args.project_dir:
        _emit({"status": "error",
               "error": "zynq-imx6-flow 仓库路径未配置：在 ~/skills_env.md 增加 "
                        "`ZYNQ_IMX6_FLOW_ROOT = <检出目录>`，或用 --project-dir 指定"}, 1)
    project = Path(args.project_dir)
    if not (project / "app" / "main_graph.py").exists():
        _emit({"status": "error",
               "error": f"app/main_graph.py not found under {project}; check --project-dir"}, 1)

    # MOCK by default so the design loop can be dry-run with no hardware attached.
    os.environ["ZYNQ_IMX6_MOCK"] = "0" if args.real else "1"
    sys.path.insert(0, str(project))

    try:
        from langgraph.checkpoint.sqlite import SqliteSaver
        from langgraph.types import Command
        from app.config import initial_state
        from app.main_graph import build_graph
    except Exception as exc:  # noqa: BLE001
        _emit({"status": "error",
               "error": f"import failed: {exc}. Run /langgraph-vivado-install to set up the env."}, 1)

    runs = project / "runs"
    runs.mkdir(exist_ok=True)
    db = str(runs / "skill_checkpoint.sqlite")
    cfg = {"configurable": {"thread_id": args.thread_id}}

    with SqliteSaver.from_conn_string(db) as cp:
        graph = build_graph(checkpointer=cp)
        try:
            if args.command == "start":
                init = initial_state(
                    program_mode=args.program_mode,
                    ps_mode=args.ps_mode,
                    board_type=args.board_type,
                    max_iterations=args.max_iterations,
                )
                if args.bit_path:
                    init["bit_path"] = args.bit_path
                if args.elf_path:
                    init["elf_path"] = args.elf_path
                if args.flash_path:
                    init["flash_path"] = args.flash_path
                graph.invoke(init, cfg)
            elif args.command == "resume":
                payload = json.loads(args.resume_json) if args.resume_json else {}
                pend = _pending(graph.get_state(cfg))
                if len(pend) <= 1:
                    graph.invoke(Command(resume=payload), cfg)
                else:
                    # Multiple interrupts pending (three-way modify fan-out). payload
                    # must be a map keyed by each interrupt's "action" (or its id).
                    resume_map = {}
                    for intr in pend:
                        val = intr.value if isinstance(intr.value, dict) else {}
                        action = val.get("action")
                        if action in payload:
                            resume_map[intr.id] = payload[action]
                        elif intr.id in payload:
                            resume_map[intr.id] = payload[intr.id]
                    if not resume_map:
                        _emit({"status": "error",
                               "error": f"resume-json keys {list(payload)} matched none of the "
                                        f"pending actions {[i.value.get('action') for i in pend]}"}, 1)
                    graph.invoke(Command(resume=resume_map), cfg)
            snap = graph.get_state(cfg)
        except Exception as exc:  # noqa: BLE001
            _emit({"status": "error", "error": str(exc)}, 1)

        pend = _pending(snap)
        if snap.next:
            _emit({
                "status": "interrupt",
                "thread_id": args.thread_id,
                "mock": not args.real,
                "next": list(snap.next),
                "iteration": snap.values.get("iteration"),
                "interrupt": pend[0].value if pend else None,
                "pending_interrupts": [i.value for i in pend],
                "pending_count": len(pend),
            }, 2)
        else:
            _emit({
                "status": "done",
                "thread_id": args.thread_id,
                "iteration": snap.values.get("iteration"),
                "meets_requirement": snap.values.get("meets_requirement"),
                "steps": len(snap.values.get("history", [])),
            }, 0)


if __name__ == "__main__":
    main()