#!/bin/bash
# cmd/main - LangBot lifecycle manager for fnOS
# Handles start / stop / status via standalone-runtime Python process.
# Node.js path is injected into PATH so Box sandbox npx MCP servers can run.

PID_FILE="${TRIM_PKGVAR}/langbot.pid"
APP_DIR="${TRIM_APPDEST}/langbot"
LOG_FILE="${TRIM_PKGVAR}/langbot.log"

# --- Locate fnOS Node.js bin path ---
# fnOS appname-based path: /var/apps/nodejs_vXX/target/bin
# This is a stable symlink regardless of which volume the app is on.
NODE_VERSION="${wizard_node_version:-22}"
NODE_BIN_DIR="/var/apps/nodejs_v${NODE_VERSION}/target/bin"

if [ -d "${NODE_BIN_DIR}" ]; then
    export PATH="${NODE_BIN_DIR}:${PATH}"
fi

# --- Persistent data root ---
# LangBot loads data/config.yaml CWD-RELATIVE (see core/stages/load_config.py:
# load_yaml_config('data/config.yaml', ...)) and resolves its data root to
# <CWD>/data in source-install mode — it does NOT honour LANGBOT_DATA_ROOT for
# config.yaml. So the real fix is the symlink below: APP_DIR/data -> DATA_DIR.
DATA_DIR="${TRIM_DATA_SHARE_PATHS%%:*}"
if [ -z "${DATA_DIR}" ]; then
    DATA_DIR="${TRIM_PKGVAR}/data"
fi
export LANGBOT_DATA_ROOT="${DATA_DIR}"
mkdir -p "${DATA_DIR}" || {
    echo "Data share not writable: ${DATA_DIR}" > "${TRIM_TEMP_LOGFILE}"
    exit 1
}

# --- Writable HOME / tool caches / venv on the data share ---
# Must match cmd/install_callback: under run-as: package neither the system
# HOME nor TRIM_APPDEST are guaranteed writable, and the venv lives at
# ${DATA_DIR}/.venv instead of inside the app dir.
export HOME="${DATA_DIR}/.home"
export UV_CACHE_DIR="${DATA_DIR}/.cache/uv"
# Never download a managed CPython — distro Python only (see install_callback)
export UV_PYTHON_DOWNLOADS=never
export UV_PROJECT_ENVIRONMENT="${DATA_DIR}/.venv"
mkdir -p "${HOME}" "${UV_CACHE_DIR}" || {
    echo "Data share not writable: ${DATA_DIR}" > "${TRIM_TEMP_LOGFILE}"
    exit 1
}

# --- CPU architecture (must be resolved before locating bundled binaries) ---
ARCH=$(uname -m)
case "${ARCH}" in
    x86_64|aarch64) ;;
    *)
        echo "Unsupported CPU architecture: ${ARCH}" > "${TRIM_TEMP_LOGFILE}"
        exit 1
        ;;
esac

# --- Locate Python: official python312 App Store app (same borrow pattern as Node.js) ---
PYTHON_BIN="/var/apps/python312/target/bin/python3"
[ -x "${PYTHON_BIN}" ] || {
    echo "Python interpreter missing or not executable: ${PYTHON_BIN} (install the python312 app)" > "${TRIM_TEMP_LOGFILE}"
    exit 1
}

# --- Locate uv: bundled binary at its single canonical path in the app dir ---
UV_BIN="${TRIM_APPDEST}/bin/uv-${ARCH}"
[ -x "${UV_BIN}" ] || {
    echo "Bundled uv binary missing or not executable: ${UV_BIN}" > "${TRIM_TEMP_LOGFILE}"
    exit 1
}

case $1 in
  start)
    if [ -f "${PID_FILE}" ]; then
        PID=$(cat "${PID_FILE}" | tr -d '[:space:]')
        if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
            exit 0
        fi
        rm -f "${PID_FILE}"
    fi

    if [ ! -d "${APP_DIR}" ]; then
        echo "LangBot app directory missing: ${APP_DIR}" > "${TRIM_TEMP_LOGFILE}"
        exit 1
    fi

    cd "${APP_DIR}" || {
        echo "Cannot enter app directory: ${APP_DIR}" > "${TRIM_TEMP_LOGFILE}"
        exit 1
    }

    if [ ! -d "${DATA_DIR}/.venv" ]; then
        echo "Python virtual environment not found. Please reinstall LangBot." > "${TRIM_TEMP_LOGFILE}"
        exit 1
    fi

    # --- Unify data location: APP_DIR/data -> symlink to persistent DATA_DIR ---
    # LangBot reads config CWD-relative (data/config.yaml), so without this a
    # fresh data/ with a default 5300 config gets recreated inside target/ on
    # every install/upgrade. The symlink keeps everything on the persistent
    # share; it is recreated here on each start (upgrades wipe target/).
    # Requires the package user to have write permission on the app dir — if
    # fnOS ever mounts it read-only, this fails loudly instead of silently
    # running against an ephemeral data directory.
    APP_DATA="${APP_DIR}/data"
    if [ -L "${APP_DATA}" ]; then
        # already a symlink; re-point if the persistent dir changed
        [ "$(readlink "${APP_DATA}")" != "${DATA_DIR}" ] && ln -sfn "${DATA_DIR}" "${APP_DATA}"
    elif [ -d "${APP_DATA}" ]; then
        # legacy real dir (created by LangBot before this fix): merge into the
        # persistent dir without overwriting newer files already there
        mkdir -p "${DATA_DIR}"
        cp -an "${APP_DATA}/." "${DATA_DIR}/." || cp -a "${APP_DATA}/." "${DATA_DIR}/"
        rm -rf "${APP_DATA}"
        ln -s "${DATA_DIR}" "${APP_DATA}"
    else
        ln -s "${DATA_DIR}" "${APP_DATA}"
    fi

    # Ensure LangBot's actual listen port always matches what fnOS shows in
    # "应用设置 → 访问端口" (which is the single source of truth from the user's
    # POV). Two sources, checked in priority order:
    #   1. ${wizard_port} — only set during install/upgrade callbacks (not on
    #      normal `start`; kept for completeness).
    #   2. target/ui/config — read the "port" field written by fnOS after
    #      ${wizard_port} substitution AND any later edit the user made via
    #      "应用设置 → 自定义 URL" pencil button.
    # Without this: user picks 5303 in wizard, LangBot still listens on its
    # default 5300, desktop shortcut hits 5303 → connection refused.
    CONFIG_FILE="${DATA_DIR}/config.yaml"
    _patch_port() {
        local _port="$1"
        case "${_port}" in
            ''|*[!0-9]*) return ;;
        esac
        if [ ! -f "${CONFIG_FILE}" ]; then
            local _tmpl="${APP_DIR}/src/langbot/templates/config.yaml"
            [ -f "${_tmpl}" ] && cp "${_tmpl}" "${CONFIG_FILE}"
        fi
        if [ -f "${CONFIG_FILE}" ]; then
            sed -i -E "/^api:/,/^[a-z_]+:/ s/^([[:space:]]*port:).*/\1 ${_port}/" "${CONFIG_FILE}"
            sed -i "s#webhook_prefix: 'http://127\.0\.0\.1:[0-9]*'#webhook_prefix: 'http://127.0.0.1:${_port}'#" "${CONFIG_FILE}"
        fi
    }
    if [ -n "${wizard_port:-}" ]; then
        _patch_port "${wizard_port}"
    fi
    if [ -f "${TRIM_APPDEST}/ui/config" ]; then
        _port_from_ui=$(python3 -c 'import json,sys
try:
    d = json.load(open(sys.argv[1]))
    for _name, _entry in (d.get(".url") or {}).items():
        p = _entry.get("port")
        if isinstance(p, (int, float)):
            print(int(p))
        elif isinstance(p, str) and p.isdigit():
            print(int(p))
        break
except Exception:
    pass
' "${TRIM_APPDEST}/ui/config" 2>/dev/null)
        if [ -n "${_port_from_ui}" ]; then
            _patch_port "${_port_from_ui}"
        fi
    fi

    # Native deployment: no --standalone-runtime flag, LangBot spawns the
    # plugin runtime as a stdio subprocess (same as official `uv run main.py`).
    # (--standalone-runtime would require an external runtime at
    #  ws://langbot_plugin_runtime:5400, which only exists in Docker Compose.)
    # --standalone-box omitted: Box sandbox defaults off, users enable via Web UI
    #
    # Privilege model: the whole app runs as the generated package user
    # (run-as: package, see config/privilege) — no root anywhere. HOME /
    # UV_CACHE_DIR / UV_PROJECT_ENVIRONMENT are exported at the top and point
    # at the persistent share so tool caches (uv, npm/npx) and the relocated
    # venv stay writable regardless of the generated user's system home.
    #
    # Process-group lifecycle: setsid makes the main process a session/group
    # leader, so PID == PGID. "stop" kills the whole group — stdio children
    # (plugin runtime, Box) die with the parent and can never survive as
    # orphans holding their ws ports after a crash, stop or upgrade.
    command -v setsid >/dev/null 2>&1 || {
        echo "setsid not found (util-linux required for process-group lifecycle)" > "${TRIM_TEMP_LOGFILE}"
        exit 1
    }
    setsid nohup "${UV_BIN}" run --no-sync main.py \
        > "${LOG_FILE}" 2>&1 &
    echo $! > "${PID_FILE}"

    sleep 3
    if [ -f "${PID_FILE}" ]; then
        PID=$(cat "${PID_FILE}" | tr -d '[:space:]')
        if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
            exit 0
        fi
    fi
    echo "LangBot failed to start. Check ${LOG_FILE}" > "${TRIM_TEMP_LOGFILE}"
    exit 1
    ;;

  stop)
    if [ -f "${PID_FILE}" ]; then
        PID=$(cat "${PID_FILE}" | tr -d '[:space:]')
        if [ -n "${PID}" ]; then
            # Started with setsid, so PID == PGID: kill the whole group so
            # stdio children (plugin runtime, Box) die with the parent. The
            # plain-PID kill covers instances started before the setsid
            # change (group kill is a no-op for them).
            kill -TERM -- "-${PID}" 2>/dev/null
            kill -TERM "${PID}" 2>/dev/null
            for _ in 1 2 3 4 5 6 7 8 9 10; do
                kill -0 "${PID}" 2>/dev/null || break
                sleep 1
            done
            kill -KILL -- "-${PID}" 2>/dev/null
            kill -KILL "${PID}" 2>/dev/null
        fi
        rm -f "${PID_FILE}"
    fi
    exit 0
    ;;

  status)
    if [ -f "${PID_FILE}" ]; then
        PID=$(cat "${PID_FILE}" | tr -d '[:space:]')
        if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
            exit 0
        fi
        rm -f "${PID_FILE}"
    fi
    exit 3
    ;;

  *)
    exit 1
    ;;
esac