#!/bin/bash
# services/voipms-trunk.sh — VoIP.ms SIP trunk add-on for asterisk-digital-ocean:
# US-only outbound (NANP dialplan restriction), capped at 3 concurrent
# outbound calls, IP-authenticated trunk (no SIP password stored), plus
# inbound routing to one extension.
#
# Requires an existing services/asterisk-digital-ocean.sh install — this adds
# a PSTN trunk on top of it and does not stand alone. See
# docs/pstn-calling-voipms-plan.md for the design/cost background this is
# built from.
#
# Part of the modular post-install system (sourced by setup.sh).

register_service voipms-trunk homelab "VoIP.ms SIP trunk for asterisk-digital-ocean — US-only outbound, max 3 concurrent calls"

# ── Surviving Easy Asterisk's regeneration ──────────────────────────────────
# Easy Asterisk (the vendor project asterisk-digital-ocean.sh builds on) fully
# OVERWRITES both pjsip.conf and extensions.conf from its own internal state:
#   - extensions.conf: rebuilt by rebuild_dialplan() on every container start,
#     and whenever a device/room is added or removed via the web admin.
#   - pjsip.conf: rewritten by generate_pjsip_conf() whenever VLAN/domain/TLS
#     settings are changed via the CLI menu (docker exec ... easy-asterisk).
#     It restores only its own "; === Device:"-marked sections from backup —
#     a hand-appended trunk section would be silently wiped the next time
#     that runs.
# So the trunk/dialplan content below lives in its own files and is
# #include'd from the generated files instead of appended directly. To make
# the #include itself survive regeneration too, _voipms_patch_vendor_files
# (below) patches it into the vendor's *generator functions* — the same
# technique this repo already uses for the logger.conf security-logging fix
# in _asterisk_do_refresh_vendor_files (see services/asterisk-digital-ocean.sh).
#
# Caveat: if the base asterisk-digital-ocean install is later refreshed
# ("update in place", which re-copies fresh vendor files) independently of
# this service, the patch is wiped along with it and needs reapplying — run
# this service again (fresh or update mode both reapply it) after any
# asterisk-digital-ocean update.

# ── Shared: patch vendor generator functions to #include our config ────────
# Anchors on "user_agent=EasyAsterisk" (pjsip.conf's [global] section) and
# "[intercom]" (extensions.conf) — each confirmed to appear exactly once per
# file in the vendor source, so this is safe regardless of what else changes
# around it upstream. Idempotent: skips files that already have the include.
_voipms_patch_vendor_files() {
    local EA_DIR="$1"
    local ENTRYPOINT="$EA_DIR/docker/entrypoint.sh"
    local EASY1="$EA_DIR/easy-asterisk.sh"
    local EASY2="$EA_DIR/easy-asterisk-v0.10.0.sh"
    local f

    for f in "$ENTRYPOINT" "$EASY1" "$EASY2"; do
        [[ -f "$f" ]] || { log_error "$f not found — is asterisk-digital-ocean fully installed?"; return 1; }
    done

    for f in "$ENTRYPOINT" "$EASY1" "$EASY2"; do
        if ! grep -q 'voipms-trunk-pjsip.conf' "$f"; then
            if grep -q '^user_agent=EasyAsterisk$' "$f"; then
                sed -i '/^user_agent=EasyAsterisk$/a #include voipms-trunk-pjsip.conf' "$f"
            else
                log_warning "$(basename "$f"): 'user_agent=EasyAsterisk' anchor not found — vendor template changed upstream."
                log_warning "  Add '#include voipms-trunk-pjsip.conf' manually after [global] in this file's pjsip.conf heredoc."
            fi
        fi
    done

    for f in "$ENTRYPOINT" "$EASY1" "$EASY2"; do
        if ! grep -q 'voipms-trunk-dialplan.conf' "$f"; then
            if grep -q '^\[intercom\]$' "$f"; then
                sed -i '/^\[intercom\]$/a #include voipms-trunk-dialplan.conf' "$f"
            else
                log_warning "$(basename "$f"): '[intercom]' anchor not found — vendor template changed upstream."
                log_warning "  Add '#include voipms-trunk-dialplan.conf' manually after [intercom] in this file's extensions.conf heredoc."
            fi
        fi
    done

    log_success "Vendor generator functions patched to include the VoIP.ms trunk config."
}

# ── Shared: pjsip trunk config (aor/identify/endpoint, IP-authenticated) ───
_voipms_write_pjsip_include() {
    local FILE="$1" SERVER="$2" SERVER_IP="$3" DID="$4"
    cat > "$FILE" << 'EOF'
; VoIP.ms trunk — IP authentication, no password stored (see
; docs/pstn-calling-voipms-plan.md). Regenerated by services/voipms-trunk.sh —
; edit there, not here directly, or a reinstall/update will overwrite this.
;
; match= below is the resolved IP of the server hostname at install time.
; VoIP.ms's servers are fixed per-POP, but if calls stop matching after a
; provider-side change, re-run this service to re-resolve and rewrite it.

[voipms-trunk]
type=aor
contact=sip:__VOIPMS_SERVER__
qualify_frequency=60

[voipms-trunk]
type=identify
endpoint=voipms-trunk
match=__VOIPMS_SERVER_IP__

[voipms-trunk]
type=endpoint
context=from-voipms
disallow=all
allow=ulaw,alaw
aors=voipms-trunk
from_user=__VOIPMS_DID__
from_domain=__VOIPMS_SERVER__
callerid=__VOIPMS_DID__
direct_media=no
EOF
    sed -i "s/__VOIPMS_SERVER_IP__/${SERVER_IP}/g; s/__VOIPMS_SERVER__/${SERVER}/g; s/__VOIPMS_DID__/${DID}/g" "$FILE"
}

# ── Shared: outbound/inbound dialplan (NANP-only, 3-concurrent cap) ────────
# Continues in the [intercom] context established just above this include
# (rebuild_dialplan() writes "[intercom]" then this #include right after it),
# so existing extensions can dial out through it directly. [from-voipms]
# below is a separate context, for calls arriving from the trunk.
_voipms_write_dialplan_include() {
    local FILE="$1" DID="$2" RING_EXT="$3"
    cat > "$FILE" << 'EOF'
; VoIP.ms outbound/inbound — US-only (NANP), max 3 concurrent outbound calls.
; Regenerated by services/voipms-trunk.sh — edit there, not here directly.
;
; No catch-all pattern here on purpose: only these two NANP patterns route
; to the trunk, so a compromised extension can't reach anything else even if
; the trunk itself would technically allow more. See
; docs/pstn-calling-voipms-plan.md for the full toll-fraud reasoning.

exten => _1NXXNXXXXX,1,NoOp(VoIP.ms outbound call to ${EXTEN})
 same => n,GotoIf($[${GROUP_COUNT(voipms-out)} >= 3]?voipms_busy,1)
 same => n,Set(GROUP()=voipms-out)
 same => n,Set(CALLERID(num)=__VOIPMS_DID__)
 same => n,Dial(PJSIP/${EXTEN}@voipms-trunk,60)
 same => n,Hangup()

exten => _NXXNXXXXX,1,NoOp(Assuming NANP, adding leading 1)
 same => n,Goto(1${EXTEN},1)

exten => voipms_busy,1,NoOp(VoIP.ms: 3 concurrent outbound calls already active — rejecting)
 same => n,Busy(15)
 same => n,Hangup()

[from-voipms]
exten => _X.,1,NoOp(Inbound PSTN call from ${CALLERID(num)})
 same => n,Dial(PJSIP/__VOIPMS_RING_EXT__,20)
 same => n,Hangup()
EOF
    sed -i "s/__VOIPMS_DID__/${DID}/g; s/__VOIPMS_RING_EXT__/${RING_EXT}/g" "$FILE"
}

install_voipms-trunk() {
    require_docker || return 1

    local EA_DIR="$DOCKER_DIR/asterisk-digital-ocean"
    local ASTERISK_DIR="$EA_DIR/config/asterisk"
    local PJSIP_INCLUDE="$ASTERISK_DIR/voipms-trunk-pjsip.conf"
    local DIALPLAN_INCLUDE="$ASTERISK_DIR/voipms-trunk-dialplan.conf"

    if [ "$DRY_RUN" = true ]; then
        echo "[DRY-RUN] Would require an existing asterisk-digital-ocean install at $EA_DIR"
        echo "[DRY-RUN] Would prompt for VoIP.ms server/POP hostname, DID, and ring extension"
        echo "[DRY-RUN] Would resolve the server hostname to an IP for inbound call matching"
        echo "[DRY-RUN] Would patch vendor generator functions to #include the trunk config"
        echo "[DRY-RUN] Would write $PJSIP_INCLUDE and $DIALPLAN_INCLUDE"
        echo "[DRY-RUN] Would offer 'update in place' instead of a fresh install if already configured"
        echo "[DRY-RUN] Would restart the asterisk container to apply"
        return 0
    fi

    if [[ ! -f "$EA_DIR/docker-compose.yml" ]]; then
        log_error "asterisk-digital-ocean isn't installed at $EA_DIR — install it first:"
        log_error "  sudo ./setup.sh asterisk-digital-ocean"
        log_error "This service adds a VoIP.ms PSTN trunk on top of it; it doesn't stand alone."
        return 1
    fi

    log_info "Configuring VoIP.ms SIP trunk for asterisk-digital-ocean..."
    log_info "US-only outbound (NANP dialplan), max 3 concurrent outbound calls, IP-authenticated trunk."
    echo ""
    log_warning "Before continuing, on VoIP.ms's side you should already have: created an"
    log_warning "account, funded the \$15 minimum prepaid balance, turned OFF auto-recharge"
    log_warning "(Client Area -> Balance Management), ordered a DID with IP authentication"
    log_warning "pointed at this droplet's public IP, and picked a server/POP. Also restrict"
    log_warning "outbound routing to US/NANP on VoIP.ms's own side if it offers that — this"
    log_warning "dialplan is the second, independent layer, not a substitute for the first."
    log_warning "See docs/pstn-calling-voipms-plan.md for the full background."
    echo ""

    # ── Existing install? Offer update-in-place instead of a full reinstall ──
    if [[ -f "$PJSIP_INCLUDE" && -f "$DIALPLAN_INCLUDE" ]]; then
        log_info "Existing VoIP.ms trunk config found."
        local REINSTALL_MODE=""
        prompt_reinstall_mode REINSTALL_MODE
        case "$REINSTALL_MODE" in
            update)
                local _SERVER _SERVER_IP _DID _RING_EXT
                _SERVER="$(grep -m1 '^from_domain=' "$PJSIP_INCLUDE" | cut -d= -f2-)"
                _SERVER_IP="$(grep -m1 '^match=' "$PJSIP_INCLUDE" | cut -d= -f2-)"
                _DID="$(grep -m1 '^from_user=' "$PJSIP_INCLUDE" | cut -d= -f2-)"
                # Match only the inbound line (Dial(PJSIP/<digits>,20)) — the
                # outbound line matches Dial(PJSIP/${EXTEN}@voipms-trunk,60),
                # which starts with "$" right after PJSIP/, not a digit.
                _RING_EXT="$(grep -m1 -E 'Dial\(PJSIP/[0-9]+,20\)' "$DIALPLAN_INCLUDE" | sed -E 's/.*Dial\(PJSIP\/([0-9]+),20\).*/\1/')"
                if [[ -z "$_SERVER" || -z "$_DID" || -z "$_RING_EXT" ]]; then
                    log_warning "Couldn't parse existing settings back out — falling back to a fresh install (every prompt below)."
                else
                    _voipms_patch_vendor_files "$EA_DIR" || return 1
                    _voipms_write_pjsip_include "$PJSIP_INCLUDE" "$_SERVER" "$_SERVER_IP" "$_DID"
                    _voipms_write_dialplan_include "$DIALPLAN_INCLUDE" "$_DID" "$_RING_EXT"
                    ensure_docker_dir_ownership "$ASTERISK_DIR"
                    ( cd "$EA_DIR" && docker compose restart asterisk ) \
                        && log_success "Updated — settings unchanged (server $_SERVER, DID $_DID, ring ext $_RING_EXT)." \
                        || log_warning "Restart failed — check: docker compose -f $EA_DIR/docker-compose.yml logs asterisk"
                    return 0
                fi
                ;;
            cancel)
                log_info "Leaving the existing VoIP.ms trunk config as-is."
                return 0
                ;;
            fresh)
                log_info "Proceeding with a full fresh reinstall — every prompt below runs from scratch."
                ;;
        esac
    fi

    # ── Prompts — VoIP.ms account details aren't scriptable, user sets these
    # up manually on VoIP.ms's own site first (see warning above) ───────────
    local VOIPMS_SERVER=""
    prompt_text "VoIP.ms server/POP hostname (e.g. atlanta2.voip.ms — pick the one closest to this droplet from VoIP.ms's server list):" "" VOIPMS_SERVER
    if [[ -z "$VOIPMS_SERVER" ]]; then
        log_error "A VoIP.ms server hostname is required — aborting."
        return 1
    fi

    local VOIPMS_SERVER_IP=""
    VOIPMS_SERVER_IP="$(getent ahostsv4 "$VOIPMS_SERVER" 2>/dev/null | awk '{print $1}' | head -1)"
    if [[ -z "$VOIPMS_SERVER_IP" ]]; then
        log_warning "Couldn't resolve $VOIPMS_SERVER — the identify section needs an IP to match inbound calls against."
        prompt_text "Enter its IP manually (check VoIP.ms's server list page):" "" VOIPMS_SERVER_IP
        if [[ -z "$VOIPMS_SERVER_IP" ]]; then
            log_error "No IP available — aborting."
            return 1
        fi
    else
        log_success "Resolved $VOIPMS_SERVER -> $VOIPMS_SERVER_IP"
    fi

    local VOIPMS_DID=""
    prompt_text "VoIP.ms DID (the 10-digit US phone number assigned to this trunk, digits only):" "" VOIPMS_DID
    if [[ ! "$VOIPMS_DID" =~ ^[0-9]{10}$ ]]; then
        log_error "That doesn't look like a 10-digit US number — aborting."
        return 1
    fi

    local RING_EXT=""
    prompt_text "Local extension to ring for inbound calls (must already exist in Easy Asterisk):" "" RING_EXT
    if [[ -z "$RING_EXT" ]]; then
        log_error "An extension number is required for inbound routing — aborting."
        return 1
    fi

    # ── Patch vendor generator functions, then write the include files ───────
    _voipms_patch_vendor_files "$EA_DIR" || return 1

    mkdir -p "$ASTERISK_DIR"
    _voipms_write_pjsip_include "$PJSIP_INCLUDE" "$VOIPMS_SERVER" "$VOIPMS_SERVER_IP" "$VOIPMS_DID"
    _voipms_write_dialplan_include "$DIALPLAN_INCLUDE" "$VOIPMS_DID" "$RING_EXT"
    ensure_docker_dir_ownership "$ASTERISK_DIR"
    chmod 644 "$PJSIP_INCLUDE" "$DIALPLAN_INCLUDE"

    # No new firewall rules: asterisk-digital-ocean.sh already opens SIP
    # (5060/5061) and RTP (10000-20000) to the internet, and VoIP.ms's source
    # IPs vary by POP/redundancy, so there's no single IP to scope this to
    # even if narrowing it were otherwise worthwhile.

    # ── Docs (separate file — asterisk-digital-ocean already owns README.md
    # in this same directory via write_readme, so don't overwrite it) ───────
    local DOC_FILE="$EA_DIR/README-voipms-trunk.md"
    cat > "$DOC_FILE" << MD
# VoIP.ms SIP trunk (add-on to asterisk-digital-ocean)

US-only outbound PSTN calling over a VoIP.ms trunk, capped at 3 concurrent
outbound calls, plus inbound routing to one extension. See
\`docs/pstn-calling-voipms-plan.md\` in the repo for the full design
background, cost estimate, and toll-fraud reasoning.

## Current settings

| Setting | Value |
|---|---|
| VoIP.ms server/POP | ${VOIPMS_SERVER} (${VOIPMS_SERVER_IP}) |
| DID | ${VOIPMS_DID} |
| Inbound rings extension | ${RING_EXT} |
| Outbound scope | US/NANP only — \`_1NXXNXXXXX\` / \`_NXXNXXXXX\` patterns, no catch-all |
| Concurrency cap | 3 simultaneous outbound calls (GROUP()/GROUP_COUNT() in the dialplan); a 4th gets a busy signal |

## How this survives Easy Asterisk's own regeneration

Easy Asterisk rewrites \`pjsip.conf\` and \`extensions.conf\` from its own
internal state (device list, network settings) rather than treating them as
hand-edited files. Trunk/dialplan config here lives in two files of its own,
\`#include\`'d from the generated files:

- \`config/asterisk/voipms-trunk-pjsip.conf\` — the trunk's \`aor\`/\`identify\`/
  \`endpoint\` sections (IP-authenticated, no password stored).
- \`config/asterisk/voipms-trunk-dialplan.conf\` — the NANP-only outbound
  routing + concurrency cap, and the \`[from-voipms]\` inbound context.

The \`#include\` lines themselves are patched into Easy Asterisk's *generator
functions* (\`docker/entrypoint.sh\`, \`easy-asterisk.sh\`,
\`easy-asterisk-v0.10.0.sh\`) so they get re-emitted every time those functions
regenerate the config, instead of being wiped.

**Caveat:** if the base \`asterisk-digital-ocean\` service is ever updated
independently (\`sudo ./setup.sh asterisk-digital-ocean\`, choosing "update in
place" — that path re-copies fresh vendor files), this patch is wiped along
with it. Re-run \`sudo ./setup.sh voipms-trunk\` afterward (update mode
reapplies the patch and rewrites both include files with your existing
settings, no re-prompting).

## Changing settings

Re-run \`sudo ./setup.sh voipms-trunk\` and choose "reinstall in place" —
current settings are read back out of the include files above and reapplied.
Choose "full install" instead to re-prompt for everything (new server, DID,
or ring extension).

## Manual edits

Don't hand-edit \`voipms-trunk-pjsip.conf\` / \`voipms-trunk-dialplan.conf\`
directly if you plan to re-run this installer later — it overwrites both
files unconditionally. If you do need one-off manual changes (e.g. testing a
second POP as a failover \`match=\` line), edit them directly and just don't
re-run the installer until you're ready to lose those changes, or restart
the container instead of running the installer to test them:

\`\`\`bash
docker compose -f $EA_DIR/docker-compose.yml restart asterisk
\`\`\`

## What the 3-call cap does and doesn't cover

It bounds *how many* outbound calls can be active at once — the first line
of defense against a compromised extension opening dozens of parallel legs.
It does not bound total spend by itself; that's still the prepaid-balance +
auto-recharge-off layer on VoIP.ms's side. Both matter — see the toll-fraud
section of \`docs/pstn-calling-voipms-plan.md\`.

## Verifying it's working

\`\`\`bash
docker exec -it easy-asterisk-do asterisk -rx "pjsip show endpoint voipms-trunk"
docker exec -it easy-asterisk-do asterisk -rx "dialplan show intercom"
docker exec -it easy-asterisk-do asterisk -rx "dialplan show from-voipms"
\`\`\`

A registered device should be able to dial a 10-digit or 11-digit US number
and reach the VoIP.ms trunk; a call to \`${VOIPMS_DID}\` from outside should
ring extension \`${RING_EXT}\`.
MD
    chown "$ACTUAL_USER:$ACTUAL_USER" "$DOC_FILE" 2>/dev/null || true

    # ── Apply ──────────────────────────────────────────────────────────────
    echo ""
    local RESTART_NOW=""
    prompt_yn "Restart the asterisk container now to apply the trunk config? (y/n):" "y" RESTART_NOW
    if [[ "$RESTART_NOW" =~ ^[Yy]$ ]]; then
        if ( cd "$EA_DIR" && docker compose restart asterisk ); then
            log_success "Asterisk restarted — trunk config applied."
        else
            log_warning "Restart failed — check: docker compose -f $EA_DIR/docker-compose.yml logs asterisk"
        fi
    else
        log_info "Apply later with: docker compose -f $EA_DIR/docker-compose.yml restart asterisk"
    fi

    echo ""
    log_success "VoIP.ms trunk configured."
    echo "  Server:        $VOIPMS_SERVER ($VOIPMS_SERVER_IP)"
    echo "  DID:           $VOIPMS_DID"
    echo "  Outbound:      US/NANP only, max 3 concurrent calls (dialplan-enforced)"
    echo "  Inbound rings: extension $RING_EXT"
    echo "  Docs:          $DOC_FILE"
    echo ""
}