#!/usr/bin/env bash

# ============================================================
# TrueNAS SSHFS Auto-Mount (Tailscale / Remote)
# Arch Linux
# ============================================================

set -u

# ---- Configuration -----------------------------------------

NAS_HOST="NAS"
MOUNT_BASE="/home/honney/mount"

mount_points=(
    "$MOUNT_BASE/Data"
    "$MOUNT_BASE/Media"
    "$MOUNT_BASE/Ripping"
    "$MOUNT_BASE/Apps"
)

remote_paths=(
    "/mnt/tank/Data"
    "/mnt/tank/Media"
    "/mnt/tank/Ripping"
    "/mnt/tank/Apps"
)

# SSHFS performance and reliability options (~30ms latency optimized)
SSHFS_OPTIONS="reconnect,ServerAliveInterval=15,ServerAliveCountMax=3,ConnectTimeout=8,ConnectionAttempts=1,cache=yes,attr_timeout=30,entry_timeout=30,negative_timeout=5"

# SSH connection test options
SSH_OPTIONS=(
    -o BatchMode=yes
    -o ConnectTimeout=8
    -o ConnectionAttempts=1
)

# ---- Logging -----------------------------------------------

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
}

# ---- Dependencies ------------------------------------------

for cmd in sshfs ssh mountpoint findmnt tailscale; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
        log "ERROR: Required command missing: $cmd"
        exit 1
    fi
done

# ---- Tailscale connectivity --------------------------------

log "Checking Tailscale..."

if ! tailscale status >/dev/null 2>&1; then
    log "ERROR: Tailscale is not running or connected."
    exit 1
fi

# Verify that the NAS is reachable through SSH using your ~/.ssh/config alias
if ! ssh "${SSH_OPTIONS[@]}" "$NAS_HOST" true; then
    log "ERROR: Cannot establish SSH connection to $NAS_HOST."
    log "Check Tailscale connectivity and your ~/.ssh/config entry."
    exit 1
fi

log "NAS reachable via SSH."
echo

# ---- Mount functions ---------------------------------------

is_mounted() {
    mountpoint -q "$1"
}

mount_sshfs() {
    local remote_path="$1"
    local mount_point="$2"

    # Create mount directory if missing
    if [[ ! -d "$mount_point" ]]; then
        log "Creating mount point: $mount_point"

        if ! mkdir -p "$mount_point"; then
            log "ERROR: Cannot create $mount_point"
            return 1
        fi
    fi

    log "Mounting $remote_path -> $mount_point"

    if sshfs \
        "$NAS_HOST:$remote_path" \
        "$mount_point" \
        -o "$SSHFS_OPTIONS"; then

        log "SUCCESS: $mount_point mounted."
        return 0
    else
        log "ERROR: Failed to mount $mount_point"
        return 1
    fi
}

# ---- Main --------------------------------------------------

success=0
failed=0
skipped=0

for i in "${!mount_points[@]}"; do

    mount_point="${mount_points[$i]}"
    remote_path="${remote_paths[$i]}"

    log "Checking: $mount_point"

    if is_mounted "$mount_point"; then

        fstype=$(findmnt -rn -M "$mount_point" -o FSTYPE)

        if [[ "$fstype" == "fuse.sshfs" ]]; then
            log "Already mounted: $mount_point"
            ((skipped+=1))
        else
            log "WARNING: Mount point occupied by another filesystem: $fstype"
            ((failed+=1))
        fi

    else

        if mount_sshfs "$remote_path" "$mount_point"; then
            ((success+=1))
        else
            ((failed+=1))
        fi

    fi

    echo

done

# ---- Summary -----------------------------------------------

log "================================================"
log "SSHFS mounting finished."
log "Successfully mounted: $success"
log "Already mounted:      $skipped"
log "Failed:               $failed"
log "================================================"

# Return failure if any mount failed
(( failed == 0 ))