#!/bin/bash
# Auto-route iPhone HFP calls (the bluez nodes exist only during a live call):
#   uplink (what far-end hears)  <- micgate.out  (GATED mic only -> no self-echo)
#   far-end voice (bluez_input)  -> callmix       (recorded digitally, clean)
# and remove WirePlumber's default callrec_mix->uplink auto-link (that mix carries
# the ungated mic AND the far-end, i.e. a digital echo loop = far-end hears itself).
#
# v2 (2026-07-30): two fixes after a call recorded near-end only + far-end doubling
#   1. every link is verified on EVERY pass, not once per call. The old one-shot
#      guard ("micgate.out already linked -> skip") meant: if the far-end node
#      appeared a tick later than the uplink node (WirePlumber does not create the
#      HFP nodes atomically), far-end->callmix was never made for the whole call,
#      and a callrec_mix->uplink link added mid-call was never removed.
#   2. port names are discovered instead of hardcoded. HFP/mSBC is MONO, so the
#      ports are playback_MONO/capture_MONO, not input_FL/input_FR. The old
#      hardcoded FL/FR grep never matched a mono node at all.
export XDG_RUNTIME_DIR=/run/user/1000
MAC=B4_96_A5_42_BD_D6

# ports_in/ports_out: list "node:port" for nodes whose name matches $1
ports_in()  { pw-link -i 2>/dev/null | grep -E "^$1"; }
ports_out() { pw-link -o 2>/dev/null | grep -E "^$1"; }

# link_all SRC_PORTS DST_PORTS -- exactly one link per DESTINATION port, cycling
# the sources. So a mono source feeds both destination channels, and a stereo
# source feeding a mono HFP port sends FL only (linking both would sum them into
# the same port = +6 dB on the uplink).
link_all() {
  local -n _src=$1 _dst=$2
  local mode=$3 i n=${#_src[@]} m=${#_dst[@]}
  [ "$n" -eq 0 ] || [ "$m" -eq 0 ] && return
  for ((i=0; i<m; i++)); do
    pw-link $mode "${_src[i % n]}" "${_dst[i]}" 2>/dev/null
  done
}

log_once=""
while true; do
  mapfile -t UP < <(ports_in "bluez_output\.${MAC}")
  if [ ${#UP[@]} -gt 0 ]; then
    B=${UP[0]%%:*}
    LINKS=$(pw-link -l "$B" 2>/dev/null)
    CHANGED=""

    # 1) drop WirePlumber's ungated-mix -> uplink link (echo source). Checked every
    #    pass because WP can (re-)add it at any point during the call.
    if echo "$LINKS" | grep -q 'callrec_mix'; then
      mapfile -t MIX < <(ports_out 'callrec_mix')
      link_all MIX UP -d
      CHANGED="$CHANGED -callrec_mix"
    fi

    # 2) ensure gated mic -> uplink
    if ! echo "$LINKS" | grep -q 'micgate\.out'; then
      mapfile -t GATE < <(ports_out 'micgate\.out')
      link_all GATE UP ""
      CHANGED="$CHANGED +micgate"
    fi

    # 3) ensure far-end -> record mix. Retried every pass: this node often shows up
    #    later than the uplink node.
    mapfile -t FAR < <(ports_out "bluez_input\.${MAC}")
    if [ ${#FAR[@]} -gt 0 ]; then
      I=${FAR[0]%%:*}
      if ! pw-link -l "$I" 2>/dev/null | grep -q 'callmix'; then
        mapfile -t REC < <(ports_in 'callmix')
        link_all FAR REC ""
        CHANGED="$CHANGED +far-end"
      fi
    else
      CHANGED="$CHANGED (no-far-end-node-yet)"
    fi

    if [ -n "$CHANGED" ] && [ "$CHANGED" != "$log_once" ]; then
      logger -t aime-iphone-route "iPhone call $B:$CHANGED"
      log_once="$CHANGED"
    fi
  else
    log_once=""
  fi
  sleep 1
done