#!/bin/bash
set -e

# --- Setup ---
BASEDIR="$(cd "$(dirname "$0")" && pwd)"
SRCDIR="$BASEDIR/.src"
SCRIPTDIR="$SRCDIR/scripts"
BACKUPDIR="/tmp/shutterlinksort-backup"

# --- Functions ---
usage() {
    cat <<EOF
Usage: sudo $0 [OPTIONS] [WEBROOT]

Options:
  --help         Show this help message
  --dry-run      Preview actions without changing any files
  --rollback     Restore the last backup
  --uninstall    Remove installed files and web content

Arguments:
  WEBROOT        Required: destination for web content

Examples:
  Install normally (default web root):
    sudo $0

  Install to custom web root:
    sudo $0 /srv/http/shutterlinksort

  Dry-run install (preview actions):
    ./install.sh --dry-run /srv/http/shutterlinksort

  Rollback from last backup:
    sudo $0 --rollback

  Uninstall installed files:
    sudo $0 --uninstall
EOF
    exit 0
}

backup_if_exists() {
    local target="$1"
    if [ -e "$target" ]; then
        local target_dir
        target_dir="$(dirname "$target")"
        if [ "$DRYRUN" = true ]; then
            echo "  [DRY-RUN] Would back up existing $(basename "$target") to $BACKUPDIR/$target_dir"
            return
        fi
        mkdir -p "$BACKUPDIR/$target_dir"
        cp -a "$target" "$BACKUPDIR/$target_dir/"
        echo "  • Backed up existing $(basename "$target")"
    fi
}

rollback() {
    if [ ! -d "$BACKUPDIR" ]; then
        echo "No backup found at $BACKUPDIR. Nothing to restore."
        exit 1
    fi
    read -pr "Are you sure you want to rollback all files from backup? [y/N]: " confirm
    if [[ "$confirm" =~ ^[Yy]$ ]]; then
        echo "=== Rolling back from backup ==="
        if [ "$DRYRUN" = true ]; then
            echo "  [DRY-RUN] Would restore backup from $BACKUPDIR to /"
        else
            cp -a "$BACKUPDIR/"* /
            echo "Rollback complete ✅"
        fi
    else
        echo "Rollback cancelled."
    fi
    exit 0
}

uninstall() {
    read -pr "Are you sure you want to uninstall all shutterlinksort files and web content? [y/N]: " confirm
    if [[ "$confirm" =~ ^[Yy]$ ]]; then
        echo "=== Uninstalling shutterlinksort ==="
        for srcfile in "$SCRIPTDIR"/shutterlinksort-*; do
            filename="$(basename "$srcfile")"
            progname="${filename%%-*}"
            pathpart="${filename#*-}"
            targetpath="${pathpart//-//}"
            target="/$targetpath/$progname"
            if [ "$DRYRUN" = true ] && [ -e "$target" ]; then
                echo "  [DRY-RUN] Would remove $target"
                continue
            fi
            if [ -e "$target" ]; then
                rm -f "$target"
                echo "  • Removed $target"
            fi
        done

        if [ -d "$WEBROOT" ]; then
            if [ "$DRYRUN" = true ]; then
                echo "  [DRY-RUN] Would remove web content at $WEBROOT"
            else
                rm -rf "$WEBROOT"
                echo "  • Removed web content at $WEBROOT"
            fi
        fi
        echo "Uninstall complete ✅"
    else
        echo "Uninstall cancelled."
    fi
    exit 0
}

# --- Parse arguments ---
DRYRUN=false
ACTION="install"

# Show usage if no arguments were provided
if [ $# -eq 0 ]; then
    usage
fi

while [ $# -gt 0 ]; do
    case "$1" in
        --help)
            usage
            ;;
        --dry-run)
            DRYRUN=true
            shift
            ;;
        --rollback|--uninstall)
            ACTION="$1"
            shift
            ;;
        *)
            WEBROOT="$1"
            shift
            ;;
    esac
done

# --- Main ---
case "$ACTION" in
    --rollback)
        rollback
        ;;
    --uninstall)
        uninstall
        ;;
    install)
        echo "=== Installing shutterlinksort components ==="
        echo "Using web root: $WEBROOT"
        echo "Backup directory: $BACKUPDIR"
        if [ "$DRYRUN" = true ]; then
            echo "[DRY-RUN mode: no files will be changed]"
        fi
        echo

        # Clear previous backup
        if [ "$DRYRUN" = true ]; then
            echo "[DRY-RUN] Would remove existing $BACKUPDIR"
        else
            rm -rf "$BACKUPDIR"
        fi

        if [ "$DRYRUN" = true ]; then
            echo "[DRY-RUN] Would create $BACKUPDIR"
        else
            mkdir -p "$BACKUPDIR"
        fi

        # Install scripts
        for srcfile in "$SCRIPTDIR"/shutterlinksort-*; do
            [ -e "$srcfile" ] || continue
            filename="$(basename "$srcfile")"
            progname="${filename%%-*}"
            pathpart="${filename#*-}"
            targetpath="${pathpart//-//}"
            target="/$targetpath/$progname"

            echo "→ Installing $progname → $target"
            mkdir -p "/$targetpath" 2>/dev/null || true
            backup_if_exists "$target"
            if [ "$DRYRUN" = true ]; then
                echo "  [DRY-RUN] Would install $srcfile → $target"
            else
                install -m 755 "$srcfile" "$target"
            fi
        done

        # Install web content
        echo
        echo "=== Installing web content ==="
        if [ "$DRYRUN" = true ]; then
            echo "  [DRY-RUN] Would create $WEBROOT"
        else
            mkdir -p "$WEBROOT"
        fi

        if [ -d "$WEBROOT" ]; then
            if [ "$DRYRUN" = true ]; then
                echo "  [DRY-RUN] Would back up existing web content to $BACKUPDIR/$(basename "$WEBROOT")"
            else
                cp -a "$WEBROOT" "$BACKUPDIR/"
            fi
        fi

        if [ "$DRYRUN" = true ]; then
            echo "  [DRY-RUN] Would copy $SRCDIR/web/ → $WEBROOT"
        else
            cp -r "$SRCDIR/web/"* "$WEBROOT/"
        fi

        echo
        echo "Web content installed to: $WEBROOT"
        echo "All backups stored in: $BACKUPDIR"
        echo "Installation complete ✅"
        echo "To rollback, run: sudo $0 --rollback"
        echo "To uninstall, run: sudo $0 --uninstall"
        ;;
esac