#!/bin/bash

if [[ "$PATH" != *"$SNAP_INSTANCE_NAME"* ]]; then
  export PATH="${PATH/\/snap\/wekan\//\/snap\/$SNAP_INSTANCE_NAME\/}"
fi

# MongoDB Control Script
# Starts MongoDB 7.x server only

# get wekan/mongo settings
echo "Reading snap settings..."
source $SNAP/bin/wekan-read-settings

# Debug: Show what we got from snap settings
echo "Snap settings loaded:"
echo "  MONGODB_BIND_IP: '${MONGODB_BIND_IP}'"
echo "  MONGODB_PORT: '${MONGODB_PORT}'"
echo "  MONGODB_BIND_UNIX_SOCKET: '${MONGODB_BIND_UNIX_SOCKET}'"

# Debug: Check snap settings directly
echo "Direct snap settings check:"
echo "  mongodb-port: $(snapctl get mongodb-port 2>/dev/null || echo 'not set')"
echo "  mongodb-bind-ip: $(snapctl get mongodb-bind-ip 2>/dev/null || echo 'not set')"
echo "  mongodb-bind-unix-socket: $(snapctl get mongodb-bind-unix-socket 2>/dev/null || echo 'not set')"

# Maintenance mode: if $SNAP_COMMON/.wekan-maintenance exists, skip ALL automatic migration
# and service-disable logic below and just start mongod, so an admin can run MongoDB by hand
# (`snap start wekan.mongodb`) to reach the data over the MongoDB wire protocol WITHOUT the
# service shutting itself down. Toggle with `snap run wekan.maintenance on|off`. NOTE: MongoDB
# and FerretDB share port 27019, so run only one of them at a time.
WEKAN_MAINTENANCE="$SNAP_COMMON/.wekan-maintenance"
if [ -f "$WEKAN_MAINTENANCE" ]; then
    echo "MAINTENANCE MODE (.wekan-maintenance present): starting MongoDB directly, skipping"
    echo "auto-migration and auto-disable. Stop with 'snap stop wekan.mongodb'."
fi

if [ "true" == "${DISABLE_MONGODB}" ]; then
    echo "mongodb is disabled. Stop service"
    snapctl stop --disable ${SNAP_NAME}.mongodb
    exit 0
fi

# The `database` snap setting is AUTHORITATIVE (see wekan-control): MongoDB is disabled only
# when database=ferretdb (below), NOT just because a FerretDB SQLite exists. This lets an admin
# keep WeKan on MongoDB (`snap run wekan.database mongodb`) while a migration is being fixed.
# A successful migration sets database=ferretdb itself (finish_success).

# First-boot migration: upgrading from an old MongoDB-based WeKan snap. Before
# starting mongod normally, hand off to migration-control, which reads the
# existing MongoDB data (mongod 7 for MongoDB 7 data — including the arm64 snaps
# on newest WeKan; the bundled old mongod for amd64 6.09/MongoDB 3.2 data),
# migrates text data to FerretDB v1 (SQLite) and CollectionFS/Meteor-Files GridFS
# attachments+avatars to the filesystem (progress at ROOT_URL, resumable), then
# switches the snap to database=ferretdb. It is idempotent and only switches on
# success; if not pending it returns non-zero and mongod starts as usual.
if [ ! -f "$WEKAN_MAINTENANCE" ] && bash "$SNAP/bin/migration-pending"; then
    echo "MongoDB -> FerretDB migration pending; running migration-control..."
    exec bash "$SNAP/bin/migration-control"
fi

# If the FerretDB backend is selected, MongoDB must not run (FerretDB binds the
# same port). Disable this service; ferretdb-control starts FerretDB instead.
if [ ! -f "$WEKAN_MAINTENANCE" ] && [ "ferretdb" == "${DATABASE}" ]; then
    echo "database is set to ferretdb. Stopping mongodb service."
    snapctl stop --disable ${SNAP_NAME}.mongodb 2>/dev/null || true
    exit 0
fi

# The replica-set setup below uses db-eval (the bundled Node.js 24 + the `mongodb`
# driver), not mongosh, so there is no client telemetry to disable. mongod itself
# has no phone-home telemetry (Cloud Free Monitoring is opt-in and stays off).
DB_EVAL="$SNAP/bin/db-eval"

# make sure we have set minimum env variables for locale
if [ -z "${LANG}" ]; then
    export LANG=en_US.UTF-8
fi

export LC_ALL=C
# If CPU does not support required instructions (AVX for x86_64, ARMv8.2-A for arm64),
# migratemongo/avx wrapper scripts transparently re-run MongoDB commands via QEMU.
# See https://github.com/wekan/migratemongo
export PATH=$SNAP/migratemongo/avx:$SNAP/usr/bin:$SNAP/bin:${PATH}
export LD_LIBRARY_PATH=$SNAP/lib:$SNAP/lib/x86_64-linux-gnu:$SNAP/lib/aarch64-linux-gnu:${LD_LIBRARY_PATH}

# If temporary settings log exists, delete it
if [ -f ${SNAP_COMMON}/settings.log ]; then
    rm ${SNAP_COMMON}/settings.log
fi

# Set MongoDB log destination to snapcommon for log file detection
export MONGO_LOG_DESTINATION="snapcommon"

# Set MongoDB data directory
export MONGO_DATA_DIR="${SNAP_COMMON}"

# Create MongoDB data directory if it doesn't exist
if [ ! -d "$MONGO_DATA_DIR" ]; then
    mkdir -p "$MONGO_DATA_DIR"
    chmod 755 "$MONGO_DATA_DIR"
fi

# Set MongoDB log file path
export MONGO_LOG_FILE="${SNAP_COMMON}/mongodb.log"

# Build bind options from snap settings
BIND_OPTIONS=""
if [ "nill" != "${MONGODB_BIND_UNIX_SOCKET}" ] && [ -n "${MONGODB_BIND_UNIX_SOCKET}" ]; then
    BIND_OPTIONS+=" --unixSocketPrefix ${MONGODB_BIND_UNIX_SOCKET}"
fi
if [ -n "${MONGODB_BIND_IP}" ]; then
    BIND_OPTIONS+=" --bind_ip ${MONGODB_BIND_IP}"
else
    BIND_OPTIONS+=" --bind_ip 127.0.0.1"
fi
if [ -n "${MONGODB_PORT}" ]; then
    BIND_OPTIONS+=" --port ${MONGODB_PORT}"
fi

# Debug: Show what settings we're using
echo "MongoDB settings:"
echo "  MONGODB_BIND_IP: ${MONGODB_BIND_IP:-127.0.0.1}"
echo "  MONGODB_PORT: ${MONGODB_PORT}"
echo "  MONGODB_BIND_UNIX_SOCKET: ${MONGODB_BIND_UNIX_SOCKET:-not set}"
echo "  BIND_OPTIONS: ${BIND_OPTIONS}"

# WiredTiger cache size, RAM-aware. This was previously HARDCODED to 32 GB, which on any
# box with less than ~34 GB RAM made mongod get OOM-killed shortly after startup: the
# temporary mongod (used to initialise the replica set) died before it could be reached,
# so the replica set was NEVER initiated, the final mongod ran with --replSet rs0 but no
# config, no PRIMARY was ever elected, and WeKan looped "MongoDB not ready yet, retrying
# in 5 seconds..." forever (issue #6454). Compute a safe value from MemTotal instead:
# ~50% of (RAM - 1 GB) - the same formula mongod uses for its own default - never above
# RAM, capped at 32 GB (the old value, kept as the ceiling for big servers), min 1 GB.
# Override with the MONGODB_WIREDTIGER_CACHE_GB env var if you need a specific size.
if [ -n "${MONGODB_WIREDTIGER_CACHE_GB}" ]; then
    WT_CACHE_GB="${MONGODB_WIREDTIGER_CACHE_GB}"
else
    _mem_kb=$(awk '/^MemTotal:/{print $2}' /proc/meminfo 2>/dev/null)
    [ -z "${_mem_kb}" ] && _mem_kb=2097152   # assume 2 GB if MemTotal is unreadable
    _mem_gb=$(( _mem_kb / 1024 / 1024 ))
    WT_CACHE_GB=$(( (_mem_gb - 1) / 2 ))
    [ "${WT_CACHE_GB}" -lt 1 ]  && WT_CACHE_GB=1
    [ "${WT_CACHE_GB}" -gt 32 ] && WT_CACHE_GB=32
fi
echo "  WiredTiger cache: ${WT_CACHE_GB} GB (RAM-aware; formerly hardcoded 32 GB - see #6454)"

# Check if MongoDB is already running
check_mongodb_running() {
    local port="${MONGODB_PORT}"

    # Check if MongoDB is already running on the configured port
    if netstat -tuln 2>/dev/null | grep -q ":${port} "; then
        echo "MongoDB is already running on port ${port}"
        return 0
    fi

    # Alternative check using lsof if netstat is not available
    if command -v lsof >/dev/null 2>&1; then
        if lsof -i ":${port}" >/dev/null 2>&1; then
            echo "MongoDB is already running on port ${port} (detected via lsof)"
            return 0
        fi
    fi

    # Check if there's a PID file and the process is still running
    if [ -f "${SNAP_COMMON}/mongodb.pid" ]; then
        local pid=$(cat "${SNAP_COMMON}/mongodb.pid" 2>/dev/null)
        if [ -n "$pid" ] && kill -0 "$pid" 2>/dev/null; then
            echo "MongoDB is already running (PID: $pid)"
            return 0
        else
            # Remove stale PID file
            rm -f "${SNAP_COMMON}/mongodb.pid"
        fi
    fi

    return 1
}

# Cleanup function to remove PID file on exit
cleanup() {
    rm -f "${SNAP_COMMON}/mongodb.pid"
}
trap cleanup EXIT

# ── #6458/#6466: decide a real outcome when mongod cannot start ──────────────
# mongod can be unable to start at all: SIGILL (exit 132) on x86_64 CPUs without
# AVX (MongoDB >= 5.0 requires AVX — #6458), or "This version of MongoDB is too
# recent to start up on the existing data files" when the data is still MongoDB
# 3.x after a failed/paused migration (#6466). Previously the exit status of the
# mongod fork was never checked: the script pinged a dead port for ~10 minutes,
# snapd restarted the service, and the cycle repeated forever while WeKan served
# 502 Bad Gateway. Instead: switch to a COMPLETED FerretDB migration if one
# exists, else (re)run the MongoDB → FerretDB migration (FerretDB is pure Go +
# SQLite — no AVX needed; MongoDB 3.x data is read with the bundled 3.2 tools),
# with a counter so a persistently failing migration cannot ping-pong forever.
MONGOD_FAIL_COUNT_FILE="${SNAP_COMMON}/.mongod-start-failures"
# A COMPLETED FerretDB migration exists (marker + non-empty SQLite): switch the
# snap to it and exit. (A PARTIAL migration — SQLite present but no marker — is
# NOT switched to.) Returns 1 when there is no completed migration.
switch_to_completed_ferretdb() {
    local svc="${SNAP_INSTANCE_NAME:-${SNAP_NAME:-wekan}}"
    if [ -f "$SNAP_COMMON/.migration-to-ferretdb-done" ] && \
       bash "$SNAP/bin/ferretdb-has-data" "$SNAP_COMMON/files/db" 2>/dev/null; then
        echo "A completed FerretDB migration exists; switching to database=ferretdb."
        snapctl set database=ferretdb 2>/dev/null || true
        snapctl start --enable "${svc}.ferretdb" 2>/dev/null || true
        snapctl restart "${svc}.ferretdb" 2>/dev/null || true
        snapctl restart "${svc}.wekan" 2>/dev/null || true
        snapctl stop --disable "${svc}.mongodb" 2>/dev/null || true
        exit 0
    fi
    return 1
}
handle_mongod_start_failure() {
    local rc="$1"
    echo "ERROR: mongod failed to start (exit code ${rc})."
    if [ "$rc" -eq 132 ]; then
        echo "Exit 132 = SIGILL (Illegal instruction): MongoDB 5.0+ x86_64 binaries require a CPU"
        echo "with AVX support (arm64: ARMv8.2-A), and this CPU has none — and no working"
        echo "qemu-user was available to emulate it (see cpu-exec in the log above)."
        echo "FerretDB (pure Go + SQLite) has no such CPU requirements and is the supported fallback."
    fi
    echo "Last mongod log lines:"
    tail -n 5 "$MONGO_LOG_FILE" 2>/dev/null || true

    switch_to_completed_ferretdb || true

    local fails=0
    [ -f "$MONGOD_FAIL_COUNT_FILE" ] && fails="$(cat "$MONGOD_FAIL_COUNT_FILE" 2>/dev/null || echo 0)"
    case "$fails" in (*[!0-9]*|'') fails=0;; esac
    fails=$((fails + 1))
    echo "$fails" > "$MONGOD_FAIL_COUNT_FILE"

    # MongoDB data that this mongod cannot serve: the only way forward is the
    # MongoDB → FerretDB migration. Re-enable and run it now (it RESUMES from its
    # checkpoint if one exists), unless it keeps failing too (counter guards
    # against a migration↔mongod restart loop).
    if [ "$fails" -le 3 ] && [ ! -f "$SNAP_COMMON/.migration-to-ferretdb-done" ] && \
       { [ -f "$SNAP_COMMON/WiredTiger" ] || ls "$SNAP_COMMON"/collection-*.wt >/dev/null 2>&1; }; then
        echo "mongod cannot serve this data; running the MongoDB -> FerretDB migration instead (attempt ${fails}/3)."
        snapctl set migrate=on 2>/dev/null || true
        rm -f "${SNAP_COMMON}/mongodb.pid"
        exec bash "$SNAP/bin/migration-control"
    fi

    echo "mongod cannot start, and the MongoDB -> FerretDB migration has not completed (attempt ${fails})."
    echo "Fix the problem, then retry/resume the migration with:  snap run wekan.migrate"
    echo "Diagnostics: ${MONGO_LOG_FILE} and ${SNAP_COMMON}/migration-*.log"
    exit 1
}

# #6458: CPU features the bundled MongoDB 7 needs: AVX on x86_64 (missing on
# old CPUs and on hypervisors/sandboxes that mask it — the #6458 report runs
# inside QEMU without AVX), ARMv8.2-A on arm64 ('atomics'/LSE is the practical
# /proc/cpuinfo proxy; Raspberry Pi 4 and older lack it). cpu-exec runs mongod
# directly when the CPU has them and through qemu-user emulation when not —
# the general mechanism replacing the old amd64-only PATH wrappers that every
# absolute-path invocation bypassed.
MONGOD_CPU_FEATURES="x86_64=avx,aarch64=atomics"
CPU_EXEC="$SNAP/bin/cpu-exec"
if [ "$(uname -m)" = "x86_64" ] && ! grep -qw avx /proc/cpuinfo 2>/dev/null; then
    echo "NOTE: This x86_64 CPU has no AVX. MongoDB 7 will run through qemu-user emulation (slower)."
    echo "The native-speed alternative is FerretDB:  snap run wekan.migrate"
    # If the FerretDB migration already completed, prefer it over emulation.
    switch_to_completed_ferretdb || true
fi

# Check if MongoDB is already running
if check_mongodb_running; then
    echo "MongoDB is already running. Exiting to prevent multiple instances."
    exit 0
fi

# Start MongoDB 7.x server
echo "Starting MongoDB 7.x server..."
# Create PID file
echo $$ > "${SNAP_COMMON}/mongodb.pid"

# Determine the expected replica set member host:port.
# Priority: port extracted from MONGO_URL if it points to localhost,
# otherwise the mongodb-port snap config (MONGODB_PORT).
INIT_MARKER="${SNAP_COMMON}/.replica_set_initialized"
_RS_PORT="${MONGODB_PORT:-27019}"
if [ -n "$MONGO_URL" ]; then
    _url_port=$(echo "$MONGO_URL" | sed -nE 's#mongodb://([^@]+@)?(127\.0\.0\.1|localhost):([0-9]+)/.*#\3#p')
    [ -n "$_url_port" ] && _RS_PORT="$_url_port"
fi
RS_MEMBER_HOST="127.0.0.1:${_RS_PORT}"
echo "Replica set member host: ${RS_MEMBER_HOST}"

# Always start MongoDB temporarily in background to verify/fix replica set
# config before the final foreground start.  This catches first-run,
# port changes, and corrupt/missing replica set state.
# Use --pidfilepath so we can kill exactly this process without touching
# MongoDB instances from other parallel snap installs.
TEMP_PID_FILE="${SNAP_COMMON}/mongod-temp.pid"
echo "Starting MongoDB temporarily to check replica set configuration..."
bash "$CPU_EXEC" --features "$MONGOD_CPU_FEATURES" $SNAP/bin/mongod \
    --dbpath="$MONGO_DATA_DIR" \
    --logpath="$MONGO_LOG_FILE" \
    --logappend $BIND_OPTIONS \
    --storageEngine wiredTiger --wiredTigerCacheSizeGB "${WT_CACHE_GB}" \
    --timeZoneInfo /usr/share/zoneinfo \
    --setParameter logicalSessionRefreshMillis=900000 \
    --setParameter localLogicalSessionTimeoutMinutes=45 \
    --replSet rs0 --oplogSize 20480 --fork \
    --pidfilepath="$TEMP_PID_FILE" \
    || handle_mongod_start_failure $?
# ^ #6458/#6466: cpu-exec runs mongod through qemu-user when the CPU lacks the
# features it needs (AVX / ARMv8.2-A). And with --fork, mongod's parent only
# returns 0 once the child is up; a SIGILL (no AVX, no qemu) or "data files too
# recent" (3.x data) failure returns non-zero and previously fell through to
# ~10 minutes of pinging a dead port, forever.

# Wait for MongoDB to accept connections (up to 30 s). db-eval uses the bundled
# Node.js + `mongodb` driver; directConnection reaches this node before the
# replica set is initiated.
echo "Waiting for MongoDB to accept connections on port ${_RS_PORT}..."
_RS_URL="mongodb://127.0.0.1:${_RS_PORT}/?directConnection=true"
_wait=0
until "$DB_EVAL" ping "$_RS_URL" >/dev/null 2>&1; do
    _wait=$((_wait + 1))
    # 90 s, not 30 s: a large production database can need more than 30 s to replay its
    # WiredTiger journal on first open. If we gave up at 30 s we would skip the replica-set
    # initialise/reconfig below, and the final mongod would then run with no elected PRIMARY
    # — WeKan would loop "MongoDB not ready yet, retrying..." forever (#6454).
    if [ $_wait -ge 90 ]; then
        echo "WARNING: MongoDB did not respond within 90 seconds"
        break
    fi
    sleep 1
done
# mongod is answering: clear the start-failure counter (see
# handle_mongod_start_failure) so past failures don't count against future ones.
[ $_wait -lt 90 ] && rm -f "$MONGOD_FAIL_COUNT_FILE"

# Check replica set status and current member host (prints OK:<host> or ERROR:<msg>)
_rs_check=$("$DB_EVAL" rs-conf-host "$_RS_URL" 2>/dev/null)
echo "Replica set check: ${_rs_check}"

if echo "$_rs_check" | grep -q "^OK:"; then
    _current_member=$(echo "$_rs_check" | sed 's/^OK://')
    if [ "$_current_member" != "$RS_MEMBER_HOST" ]; then
        echo "Member host mismatch: current='${_current_member}', expected='${RS_MEMBER_HOST}'. Reconfiguring..."
        "$DB_EVAL" rs-reconfig "$_RS_URL" "$RS_MEMBER_HOST" 2>/dev/null || true
    else
        echo "Replica set config is valid."
    fi
else
    # Not initialized or config is invalid — try initiate first, then reconfig
    echo "Replica set not ready. Initializing with member: ${RS_MEMBER_HOST}..."
    "$DB_EVAL" rs-initiate "$_RS_URL" "$RS_MEMBER_HOST" 2>/dev/null \
        || "$DB_EVAL" rs-reconfig "$_RS_URL" "$RS_MEMBER_HOST" 2>/dev/null || true
fi

# Ensure init marker exists regardless of path taken above
[ -f "$INIT_MARKER" ] || touch "$INIT_MARKER"

# Shut down the temporary MongoDB process using its PID file so we only
# kill this instance and never another parallel snap's mongod.
echo "Stopping temporary MongoDB process..."
"$DB_EVAL" shutdown "$_RS_URL" 2>/dev/null || true
sleep 2
if [ -f "$TEMP_PID_FILE" ]; then
    kill "$(cat "$TEMP_PID_FILE")" 2>/dev/null || true
    rm -f "$TEMP_PID_FILE"
fi
sleep 1

# Final start of MongoDB in foreground (this stays the main process; #6458/#6466:
# not `exec` anymore, so an IMMEDIATE startup crash — SIGILL on non-AVX CPUs,
# incompatible data files — is caught below instead of snapd blindly restarting
# this service into the same crash forever)
_mongod_start_ts=$(date +%s)
bash "$CPU_EXEC" --features "$MONGOD_CPU_FEATURES" $SNAP/bin/mongod \
    --dbpath="$MONGO_DATA_DIR" \
    --logpath="$MONGO_LOG_FILE" \
    --logappend $BIND_OPTIONS \
    --storageEngine wiredTiger --wiredTigerCacheSizeGB "${WT_CACHE_GB}" \
    --timeZoneInfo /usr/share/zoneinfo \
    --setParameter logicalSessionRefreshMillis=900000 \
    --setParameter localLogicalSessionTimeoutMinutes=45 \
    --replSet rs0 --oplogSize 20480
_mongod_rc=$?
if [ $_mongod_rc -ne 0 ] && [ $(( $(date +%s) - _mongod_start_ts )) -lt 15 ]; then
    # Died within seconds of starting: a startup failure, not a normal shutdown.
    handle_mongod_start_failure $_mongod_rc
fi
exit $_mongod_rc