#!/usr/bin/env python3
"""VS Code/GitHub Copilot adapter for the CASAN-owned `@casan` participant.

The VS Code extension owns the request and native model call, while this thin
adapter maps participant lifecycle messages to the shared Plan-20 bridge.  It
does not call a model and it does not claim to intercept built-in Copilot chat.
"""

from __future__ import annotations

import argparse
import json
import os
import sys

_ADAPTER_DIR = os.path.dirname(os.path.abspath(__file__))
_BRIDGE_DIR = os.path.abspath(os.path.join(_ADAPTER_DIR, "..", "..", "scripts", "python"))
if _BRIDGE_DIR not in sys.path:
    sys.path.insert(0, _BRIDGE_DIR)

import agentic_bridge as bridge  # noqa: E402

ADAPTER_VERSION = "20.2.0-vscode"


def emit(value, exit_code=0):
    sys.stdout.write(json.dumps(value, ensure_ascii=False) + "\n")
    return exit_code


def handle_begin(payload):
    response = bridge.op_begin({
        "op": "begin",
        "client": "vscode",
        "client_version": payload.get("client_version"),
        "adapter_version": ADAPTER_VERSION,
        "project": payload.get("project") or payload.get("cwd"),
        "session": payload.get("session_id"),
        "turn": payload.get("turn_id"),
        "prompt": payload.get("prompt", ""),
        # The explicit @casan participant owns the complete model lifecycle.
        "integration_mode": "casan_owned",
    })
    return emit(response, 2 if response.get("decision") == "block" else 0)


def handle_finalize(payload):
    response = bridge.op_finalize({
        "op": "finalize",
        "admission_id": payload.get("admission_id", ""),
        "stop_reason": payload.get("stop_reason") or "completed",
        "assistant_summary": payload.get("assistant_summary"),
    })
    return emit(response)


def handle_abort(payload):
    response = bridge.op_abort({
        "op": "abort",
        "admission_id": payload.get("admission_id", ""),
        "reason": payload.get("reason") or "vscode_participant_aborted",
    })
    return emit(response)


def handle_telemetry(payload):
    response = bridge.op_telemetry({
        "op": "telemetry",
        "admission_id": payload.get("admission_id", ""),
        "model": payload.get("model"),
        "runtime_ms": payload.get("runtime_ms"),
        "input_tokens": payload.get("input_tokens"),
        "output_tokens": payload.get("output_tokens"),
        "cost_amount": payload.get("cost_amount"),
        "cost_currency": payload.get("cost_currency"),
        "cost_source": payload.get("cost_source"),
    })
    return emit(response)


HANDLERS = {
    "Begin": handle_begin,
    "Finalize": handle_finalize,
    "Abort": handle_abort,
    "Telemetry": handle_telemetry,
}


def main(argv=None):
    parser = argparse.ArgumentParser(description="CASAN VS Code participant adapter")
    parser.add_argument("--event", required=True, choices=sorted(HANDLERS))
    args = parser.parse_args(argv)
    try:
        payload = json.loads(sys.stdin.read() or "{}")
    except ValueError:
        return emit({"decision": "block", "reason": "invalid_json"}, 2)
    try:
        return HANDLERS[args.event](payload)
    except Exception as exc:  # noqa: BLE001 - adapter boundary
        return emit({"decision": "block", "reason": "adapter_error:%s" % exc}, 2)


if __name__ == "__main__":
    raise SystemExit(main())