"""Console commands and CVars.

Ops:
  run        {command}                — execute editor console command
  get_cvar   {name}
  set_cvar   {name, value}
  list_cvars {prefix?}                — search registered cvars by prefix (best-effort)
  stat       {name, enable?:true}     — toggle stat command (`stat fps`, `stat unit`, ...)
"""
from __future__ import annotations

import json
import os
import traceback

try:
    import unreal  # type: ignore
except ImportError:
    unreal = None


def _world():
    return unreal.EditorLevelLibrary.get_editor_world()


def run(args):
    cmd = args["command"]
    try:
        unreal.SystemLibrary.execute_console_command(_world(), cmd)
        return {"ok": True, "command": cmd}
    except Exception as e:
        return {"ok": False, "error": str(e)}


def get_cvar(args):
    name = args["name"]
    # No direct read API in stable Python; we issue ?-style print and grab from log.
    try:
        unreal.SystemLibrary.execute_console_command(_world(), name)
        # Heuristic: also use ConsoleVariablesEditorFunctionLibrary if available
        cvl = getattr(unreal, "ConsoleVariablesEditorFunctionLibrary", None)
        if cvl and hasattr(cvl, "get_console_variable_string_value"):
            return {"ok": True, "name": name, "value": cvl.get_console_variable_string_value(name)}
        return {"ok": True, "name": name, "note": "value echoed to Output Log (no direct read API)"}
    except Exception as e:
        return {"ok": False, "error": str(e)}


def set_cvar(args):
    name = args["name"]
    val = args["value"]
    cmd = f"{name} {val}"
    try:
        unreal.SystemLibrary.execute_console_command(_world(), cmd)
        return {"ok": True, "command": cmd}
    except Exception as e:
        return {"ok": False, "error": str(e)}


def list_cvars(args):
    prefix = args.get("prefix") or ""
    cmd = f"DumpConsoleCommands {prefix}".strip()
    try:
        unreal.SystemLibrary.execute_console_command(_world(), cmd)
        return {"ok": True, "note": "results dumped to log; use read_python_log or grep the project log",
                "command": cmd}
    except Exception as e:
        return {"ok": False, "error": str(e)}


def stat(args):
    name = args["name"]
    if not name.lower().startswith("stat "):
        name = "stat " + name
    try:
        unreal.SystemLibrary.execute_console_command(_world(), name)
        return {"ok": True, "command": name}
    except Exception as e:
        return {"ok": False, "error": str(e)}


OPS = {
    "run":        run,
    "get_cvar":   get_cvar,
    "set_cvar":   set_cvar,
    "list_cvars": list_cvars,
    "stat":       stat,
}


def entrypoint(payload_json):
    try:
        p = json.loads(payload_json)
    except Exception as e:
        return _tee({"ok": False, "error": f"bad json: {e}"}, {})
    op = p.get("op"); fn = OPS.get(op)
    if not fn:
        return _tee({"ok": False, "error": f"unknown op {op!r}", "available": list(OPS)}, p)
    try:
        return _tee(fn(p), p)
    except Exception as e:
        return _tee({"ok": False, "error": str(e), "traceback": traceback.format_exc()}, p)


def _tee(result, p):
    txt = json.dumps(result)
    try:
        if unreal is not None:
            sd = unreal.Paths.project_saved_dir() + "MCP/"
            os.makedirs(sd, exist_ok=True)
            rid = p.get("__rid") or "last"
            with open(sd + "last.json", "w", encoding="utf-8") as f: f.write(txt)
            if rid != "last":
                with open(sd + f"{rid}.json", "w", encoding="utf-8") as f: f.write(txt)
            unreal.log("[MCP-CONSOLE] " + txt[:1500])
    except Exception:
        pass
    return txt