#!/usr/bin/env bash
set -euo pipefail
# POS: system dashboard — Web dashboard: start/stop/status/config/url
# POS_FLAGS: --help
# POS_SUBCMDS: start stop status port config url
# POS_CONFIG: dashboard | dashboard.env | DASHBOARD_PORT=num:Port the dashboard listens on (default 8080) | DASHBOARD_HOST=:Bind address (default 0.0.0.0)

source "$(dirname "$0")/../lib/common.sh" 2>/dev/null || source "$(dirname "$0")/common.sh"

# ── Config & constants ──────────────────────────────────────────
CONFIG_DIR="${CONFIG_DIR:-${XDG_CONFIG_HOME:-$HOME/.config}/linux_post_install}"
CONFIG_FILE="$CONFIG_DIR/dashboard.env"
SERVICE="pos-dashboard.service"
USER_SYSTEMD_DIR="${USER_SYSTEMD_DIR:-${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user}"
DASHBOARD_DIR="/usr/local/share/linux_post_install/dashboard"
DASHBOARD_SCRIPT="$DASHBOARD_DIR/app.py"

# ── load config ─────────────────────────────────────────────────
load_config() {
    [ -f "$CONFIG_FILE" ] || return 0
    local k v
    while IFS='=' read -r k v; do
        [ -n "$k" ] || continue
        case "$k" in
            \#*) continue ;;
        esac
        v="${v%\"}"; v="${v#\"}"; v="${v%\'}"; v="${v#\'}"
        if [ -z "${!k:-}" ]; then
            export "$k"="$v"
        fi
    done < <(grep -E '^[A-Z_]+=' "$CONFIG_FILE" || true)
}

# ── defaults ────────────────────────────────────────────────────
load_config
DASHBOARD_PORT="${DASHBOARD_PORT:-8080}"
DASHBOARD_HOST="${DASHBOARD_HOST:-0.0.0.0}"

# ── usage ───────────────────────────────────────────────────────
usage() {
    cat <<EOF
Usage: pos dashboard <command>

Web dashboard for the pos toolkit — browser-based UI for managing
entertainment, Telegram, Docker, and system health.

Commands:
  start       Install and start the systemd user service
  stop        Stop, disable, and remove the service
  status      Show service state and the dashboard URL
  port <num>  Change the dashboard port (restarts the service)
  config      Edit DASHBOARD_PORT, DASHBOARD_HOST
  url         Print the dashboard URL

Config:  $CONFIG_FILE  (DASHBOARD_PORT, DASHBOARD_HOST)
Service: $SERVICE (systemd user unit)
Dir:     $DASHBOARD_DIR

The dashboard binds to DASHBOARD_HOST:DASHBOARD_PORT (default 0.0.0.0:8080).
Access it over Tailscale at: http://<tailscale-ip>:<port>/

Examples:
  pos dashboard start
  pos dashboard port 9090
  pos dashboard status
  pos dashboard url
  pos dashboard config
EOF
    exit 0
}

# ── deps guard (before --help, per convention) ──────────────────
command -v python3 &>/dev/null || err "python3 not found — install with: sudo apt install python3"

# ── help ────────────────────────────────────────────────────────
case "${1:-}" in
    -h|--help) usage ;;
esac

# ── start ───────────────────────────────────────────────────────
cmd_start() {
    # Check flask is available
    if ! python3 -c "import flask" 2>/dev/null; then
        err "python3-flask not installed — install with: sudo apt install python3-flask"
    fi

    # Check dashboard directory exists
    if [ ! -d "$DASHBOARD_DIR" ]; then
        err "Dashboard directory not found: $DASHBOARD_DIR — run install.sh first"
    fi
    if [ ! -f "$DASHBOARD_SCRIPT" ]; then
        err "Dashboard app not found: $DASHBOARD_SCRIPT — run install.sh first"
    fi

    # Ensure config exists
    if [ ! -f "$CONFIG_FILE" ]; then
        mkdir -p "$CONFIG_DIR"
        cp "${BASH_SOURCE[0]%/bin/pos-dashboard}/../config/dashboard.env" "$CONFIG_FILE" 2>/dev/null \
            || warn "No config template found — create $CONFIG_FILE manually"
        chmod 600 "$CONFIG_FILE" 2>/dev/null || true
    fi

    # Install systemd user service
    mkdir -p "$USER_SYSTEMD_DIR"

    local runner
    if [ -x /usr/local/bin/pos-dashboard ]; then
        runner=/usr/local/bin/pos-dashboard
    else
        runner="$(cd "$(dirname "$0")/.." && pwd)/bin/pos-dashboard"
        warn "using repo path $runner — re-run 'install.sh' so the service survives a deleted repo"
    fi

    cat >"$USER_SYSTEMD_DIR/$SERVICE" <<EOF
[Unit]
Description=pos Web Dashboard
After=network.target

[Service]
Type=simple
ExecStart=/usr/bin/python3 $DASHBOARD_SCRIPT
Restart=on-failure
RestartSec=5
EnvironmentFile=%h/.config/linux_post_install/dashboard.env

[Install]
WantedBy=default.target
EOF
    chmod 644 "$USER_SYSTEMD_DIR/$SERVICE"

    systemctl --user daemon-reload
    systemctl --user enable --now "$SERVICE"
    log "Dashboard service enabled: $SERVICE"

    cmd_url

    if command -v loginctl >/dev/null 2>&1; then
        if ! loginctl show-user "$(id -un)" 2>/dev/null | grep -q '^Linger=yes'; then
            warn "enable linger so the dashboard survives logout: sudo loginctl enable-linger $(id -un)"
        fi
    fi
}

# ── stop ────────────────────────────────────────────────────────
cmd_stop() {
    if [ ! -f "$USER_SYSTEMD_DIR/$SERVICE" ]; then
        warn "no dashboard service installed ($SERVICE)"
        return 0
    fi
    systemctl --user disable --now "$SERVICE" 2>/dev/null || true
    rm -f "$USER_SYSTEMD_DIR/$SERVICE"
    systemctl --user daemon-reload
    log "Dashboard service disabled"
}

# ── status ──────────────────────────────────────────────────────
cmd_status() {
    load_config
    DASHBOARD_PORT="${DASHBOARD_PORT:-8080}"
    DASHBOARD_HOST="${DASHBOARD_HOST:-0.0.0.0}"
    if systemctl --user is-active --quiet "$SERVICE" 2>/dev/null; then
        echo "service:   running"
    else
        echo "service:   not running"
    fi
    if systemctl --user is-enabled "$SERVICE" >/dev/null 2>&1; then
        echo "autostart: enabled (starts on login)"
    else
        echo "autostart: disabled"
    fi
    echo "config:    $CONFIG_FILE"
    echo "dir:       $DASHBOARD_DIR"
    cmd_url
}

# ── port ────────────────────────────────────────────────────────
cmd_port() {
    local new_port="${1:-}"
    if [ -z "$new_port" ]; then
        err "Usage: pos dashboard port <number>"
    fi
    # Validate port is a number between 1 and 65535
    if ! [[ "$new_port" =~ ^[0-9]+$ ]] || [ "$new_port" -lt 1 ] || [ "$new_port" -gt 65535 ]; then
        err "Invalid port: $new_port — must be a number between 1 and 65535"
    fi

    # Ensure config file exists
    if [ ! -f "$CONFIG_FILE" ]; then
        mkdir -p "$CONFIG_DIR"
        cp "${BASH_SOURCE[0]%/bin/pos-dashboard}/../config/dashboard.env" "$CONFIG_FILE" 2>/dev/null \
            || echo -e "DASHBOARD_PORT=8080\nDASHBOARD_HOST=0.0.0.0" > "$CONFIG_FILE"
        chmod 600 "$CONFIG_FILE"
    fi

    # Update port in config file
    if grep -q '^DASHBOARD_PORT=' "$CONFIG_FILE"; then
        sed -i "s/^DASHBOARD_PORT=.*/DASHBOARD_PORT=$new_port/" "$CONFIG_FILE"
    else
        echo "DASHBOARD_PORT=$new_port" >> "$CONFIG_FILE"
    fi
    log "Port changed to $new_port in $CONFIG_FILE"

    # Update the running variable so cmd_url shows the new port
    DASHBOARD_PORT="$new_port"

    # Restart service if running
    if systemctl --user is-active --quiet "$SERVICE" 2>/dev/null; then
        systemctl --user restart "$SERVICE"
        log "Dashboard service restarted on port $new_port"
    else
        warn "Dashboard is not running — start it with: pos dashboard start"
    fi

    cmd_url
}

# ── config ──────────────────────────────────────────────────────
cmd_config() {
    # If pos config-ui.sh is available, use the interactive editor
    local cfg_ui_script
    for p in \
        "$(dirname "$0")/../lib/config-ui.sh" \
        "$(dirname "$0")/config-ui.sh" \
        "/usr/local/bin/config-ui.sh"; do
        if [ -f "$p" ]; then
            cfg_ui_script="$p"
            break
        fi
    done
    if [ -n "${cfg_ui_script:-}" ]; then
        source "$cfg_ui_script" 2>/dev/null
        cfg_ui "dashboard"
        return
    fi

    # Fallback: reload and show current values
    load_config
    DASHBOARD_PORT="${DASHBOARD_PORT:-8080}"
    DASHBOARD_HOST="${DASHBOARD_HOST:-0.0.0.0}"
    echo "Dashboard config: $CONFIG_FILE"
    echo
    printf '  DASHBOARD_PORT=%s\n' "$DASHBOARD_PORT"
    printf '  DASHBOARD_HOST=%s\n' "$DASHBOARD_HOST"
    echo
    echo "Edit with: pos config dashboard"
}

# ── url ─────────────────────────────────────────────────────────
cmd_url() {
    local ip=""
    # Prefer Tailscale IP
    if command -v tailscale &>/dev/null; then
        ip="$(tailscale ip -4 2>/dev/null || true)"
    fi
    # Fallback to first non-loopback IP
    if [ -z "$ip" ]; then
        ip="$(hostname -I 2>/dev/null | awk '{print $1}')"
    fi
    if [ -z "$ip" ]; then
        ip="localhost"
    fi
    echo "http://${ip}:${DASHBOARD_PORT}/"
}

# ── dispatch ────────────────────────────────────────────────────
case "${1:-}" in
    start)  cmd_start  ;;
    stop)   cmd_stop   ;;
    status) cmd_status ;;
    port)   cmd_port "${2:-}" ;;
    config) cmd_config ;;
    url)    cmd_url    ;;
    "")     usage      ;;
    *)      err "Unknown subcommand '$1' (see --help)" ;;
esac