"""
Twilio webhook handlers — TwiML responses for outbound government hold-line calls.

Twilio calls these endpoints during a live call to get instructions (TwiML XML).
The initiating script (app/dialers/ftb.py) starts the call; Twilio fetches
/webhooks/twilio/twiml to know what to do once the call connects.
"""
from __future__ import annotations

import os
from fastapi import APIRouter, Form, Response
from fastapi.responses import PlainTextResponse

router = APIRouter(prefix="/webhooks/twilio")

# Phone number to bridge the user into the call once we're in queue.
# Set via OSPREY_BRIDGE_NUMBER env var (E.164 format, e.g. +15105551234).
BRIDGE_NUMBER = os.environ.get("OSPREY_BRIDGE_NUMBER", "")


def _xml(body: str) -> Response:
    """Wrap TwiML body in <Response> and return with correct content-type."""
    return Response(
        content=f'<?xml version="1.0" encoding="UTF-8"?><Response>{body}</Response>',
        media_type="application/xml",
    )


@router.post("/twiml")
async def twiml_navigate():
    """
    Called by Twilio when the outbound call to the agency connects.
    Returns TwiML that navigates the IVR and then holds.

    IVR sequence is loaded from OSPREY_IVR_SEQUENCE env var —
    a comma-separated list of DTMF digits/pauses, e.g. "1,,,2,,,0"
    where commas are 0.5s pauses between digits.

    After navigation, we pause for 45s. If the call is still alive
    at the /status callback, the status handler initiates the bridge call.
    """
    sequence = os.environ.get("OSPREY_IVR_SEQUENCE", "")
    digits = sequence.replace(" ", "")  # strip accidental spaces

    # Build <Play digits="..."> for DTMF — commas are 0.5s pauses in DTMF notation
    ivr_twiml = f'<Play digits="{digits}"/>' if digits else ""

    # Hold for long enough to confirm we're in queue before bridging.
    # 45s covers the IVR tree + any initial hold announcement.
    hold_twiml = "<Pause length='45'/>"

    # After holding, redirect to the bridge endpoint to connect the user.
    bridge_url = os.environ.get("OSPREY_BASE_URL", "").rstrip("/") + "/webhooks/twilio/bridge"
    redirect_twiml = f"<Redirect>{bridge_url}</Redirect>"

    return _xml(ivr_twiml + hold_twiml + redirect_twiml)


@router.post("/status")
async def call_status(
    CallStatus: str = Form(...),
    CallDuration: str = Form("0"),
    CallSid: str = Form(""),
):
    """
    Twilio posts here on every call status change.
    We log rejections (short duration + completed/busy/failed) for retry logic.
    The dialer script polls a shared state file; this endpoint writes to it.
    """
    duration = int(CallDuration or 0)
    rejected = CallStatus in ("completed", "busy", "failed", "no-answer") and duration < 30

    state_file = os.environ.get("OSPREY_STATE_FILE", "/tmp/osprey_call_state.txt")
    with open(state_file, "w") as f:
        f.write(f"{CallStatus}:{duration}:{CallSid}")

    if rejected:
        print(f"[Osprey] Call {CallSid} rejected after {duration}s — will retry")
    else:
        print(f"[Osprey] Call {CallSid} status={CallStatus} duration={duration}s")

    return PlainTextResponse("OK")


@router.post("/bridge")
async def bridge_call():
    """
    Called after the hold period — we're confident we're in the queue.
    Dials OSPREY_BRIDGE_NUMBER and connects both legs into a conference.
    """
    if not BRIDGE_NUMBER:
        # No bridge number configured — just keep holding silently.
        return _xml("<Pause length='3600'/>")

    # <Dial> with <Conference> bridges both legs into a named room.
    # waitUrl="" suppresses hold music on our side (FTB's hold music is already playing).
    conference_twiml = (
        "<Dial>"
        f"  <Number statusCallbackEvent='answered' statusCallback='/webhooks/twilio/status'>"
        f"    {BRIDGE_NUMBER}"
        "  </Number>"
        "</Dial>"
    )
    return _xml(conference_twiml)