#!/bin/bash
# LibrePortal ownership-reconcile helper — the ONLY root-privileged file-ownership
# operation the manager is allowed to trigger via sudo.
#
# Why this exists: under Model A the runtime executes AS the manager (libreportal),
# so establishing the ownership model (manager owns the control plane, the docker
# install user owns the containers + backups) needs root. Granting the manager a
# blanket `sudo chown`/`sudo chmod` would be root-equivalent (chown /etc/sudoers,
# etc.). Instead this script — installed root:root 0755 to /usr/local/lib/libreportal/
# by init.sh, so the manager cannot modify it — performs a FIXED set of reconciles
# on FIXED LibrePortal paths only. The roots and the manager name are BAKED at
# install (sed placeholders), never read at runtime from a manager-writable config;
# the single free argument (an app name / relpath) is strictly validated.
#
# Layout — three independently-relocatable roots, each owned by ONE principal:
#   SYSTEM_DIR     manager-owned control plane (configs/logs/install/db/ssl/ssh/…)
#   CONTAINERS_DIR container-user-owned live app data (apps live directly under it)
#   BACKUPS_DIR    container-user-owned backup repos (own mount-able)
#
# Self-contained ON PURPOSE: it must NOT source any manager-owned code (incl.
# paths.sh), or it would re-open the very escalation it exists to close. init.sh is
# the source of truth for the install; it bakes the values into the installed copy.

set -u

[[ $EUID -eq 0 ]] || { echo "libreportal-ownership: must run as root" >&2; exit 1; }

# Baked by init.sh at install (placeholders replaced). An unbaked copy (run
# directly from the repo before baking) still contains the "__" sentinel, which no
# real absolute path does — fall back to the defaults in that case only.
MANAGER="__MANAGER__"
CONTAINERS_DIR="__CONTAINERS_DIR__"
BACKUPS_DIR="__BACKUPS_DIR__"
SYSTEM_DIR="__SYSTEM_DIR__"
[[ "$MANAGER"        == *"__"* || -z "$MANAGER"        ]] && MANAGER="libreportal"
[[ "$SYSTEM_DIR"     == *"__"* || -z "$SYSTEM_DIR"     ]] && SYSTEM_DIR="/libreportal-system"
[[ "$CONTAINERS_DIR" == *"__"* || -z "$CONTAINERS_DIR" ]] && CONTAINERS_DIR="/libreportal-containers"
[[ "$BACKUPS_DIR"    == *"__"* || -z "$BACKUPS_DIR"    ]] && BACKUPS_DIR="/libreportal-backups"

# Refuse to operate on dangerous roots even if mis-baked (defence in depth).
for _d in "$SYSTEM_DIR" "$CONTAINERS_DIR" "$BACKUPS_DIR"; do
    case "$_d" in
        /|/etc|/usr|/bin|/sbin|/lib|/lib64|/boot|/proc|/sys|/dev|/run|/home|/root|/var|/tmp)
            echo "libreportal-ownership: refusing dangerous root '$_d'" >&2; exit 1 ;;
        /*) ;;  # absolute — ok
        *)  echo "libreportal-ownership: root must be absolute: '$_d'" >&2; exit 1 ;;
    esac
done

CONFIGS_DIR="$SYSTEM_DIR/configs"
LOGS_DIR="$SYSTEM_DIR/logs"
INSTALL_DIR="$SYSTEM_DIR/install"
SSL_DIR="$SYSTEM_DIR/ssl"
SSH_DIR="$SYSTEM_DIR/ssh"
RESTORE_DIR="$SYSTEM_DIR/restore"
MIGRATE_DIR="$SYSTEM_DIR/migrate"
DB_PATH="$SYSTEM_DIR/database.db"
WEBUI_DIR="$CONTAINERS_DIR/libreportal"
TASK_DIR="$WEBUI_DIR/frontend/data/tasks"
DB_CFG="$CONFIGS_DIR/general/general_docker_install"

# Current docker mode, read authoritatively from config (read-only — informs the
# container OWNER choice, not any path).
_mode() {
    local m
    m=$(grep -h '^CFG_DOCKER_INSTALL_TYPE=' "$DB_CFG" 2>/dev/null | head -1 | cut -d= -f2 | awk '{print $1}')
    echo "${m:-rootless}"
}

# Who owns container/backup data for a mode: rooted -> the manager; rootless -> the
# configured docker install user (must be a real account, else fall back).
_container_owner() {
    local mode="$1" appusr=""
    if [[ "$mode" == "rootless" ]]; then
        appusr=$(grep -h '^CFG_DOCKER_INSTALL_USER=' "$DB_CFG" 2>/dev/null | head -1 | cut -d= -f2 | awk '{print $1}')
        if [[ -n "$appusr" ]] && id -u "$appusr" >/dev/null 2>&1; then
            echo "$appusr"; return
        fi
        echo "dockerinstall"
    else
        echo "$MANAGER"
    fi
}

# Validate + resolve an app name to its container dir (reject traversal/odd names).
_app_dir() {
    local app="$1"
    [[ "$app" =~ ^[A-Za-z0-9._-]+$ && "$app" != "." && "$app" != ".." ]] \
        || { echo "libreportal-ownership: invalid app name" >&2; return 1; }
    local d="$CONTAINERS_DIR/$app"
    [[ -d "$d" ]] || { echo "libreportal-ownership: no such app dir: $d" >&2; return 1; }
    printf '%s' "$d"
}

# Let the rootless container user reach the few system-tree files it must read as
# bind-mount sources (the WebUI's configs/webui/*), WITHOUT exposing the rest of
# the control plane — or those files' contents to other local users.
#
# Access is granted via the GROUP, not world: under rootless the container's gid 0
# maps to the container owner's gid on the host, so group-read is enough for the
# container while other local users get nothing. Owner stays the manager so the
# control plane can still rewrite them; the dir keeps only o+x (traverse, not list).
# This is what keeps secrets like webui_logins from being world-readable.
_webui_bind_access() {
    chmod o+x "$SYSTEM_DIR" 2>/dev/null
    [[ -d "$CONFIGS_DIR" ]] && chmod o+x "$CONFIGS_DIR" 2>/dev/null
    if [[ -d "$CONFIGS_DIR/webui" ]]; then
        local cowner; cowner="$(_container_owner "$(_mode)")"
        chown "$MANAGER:$cowner" "$CONFIGS_DIR/webui" 2>/dev/null
        chmod 0751 "$CONFIGS_DIR/webui" 2>/dev/null
        find "$CONFIGS_DIR/webui" -maxdepth 1 -type f \
            -exec chown "$MANAGER:$cowner" {} \; -exec chmod 0640 {} \; 2>/dev/null
    fi
}

# Control plane -> manager; container + backup roots -> container owner.
reconcile() {
    local mode="${1:-$(_mode)}"
    local cowner; cowner="$(_container_owner "$mode")"

    if [[ -d "$SYSTEM_DIR" ]]; then
        chown "$MANAGER:$MANAGER" "$SYSTEM_DIR"
        local p
        for p in "$CONFIGS_DIR" "$LOGS_DIR" "$INSTALL_DIR" "$SSL_DIR" "$SSH_DIR" \
                 "$RESTORE_DIR" "$MIGRATE_DIR" "$DB_PATH"; do
            [[ -e "$p" ]] && chown -R "$MANAGER:$MANAGER" "$p"
        done
        [[ -f "$DB_PATH" ]] && chmod o+r "$DB_PATH"
        _webui_bind_access
    fi

    # Data + backups: wholly the container owner's (rootless requires it; this is
    # also what lets restic — which runs AS that user — write the backup repos).
    local d
    for d in "$CONTAINERS_DIR" "$BACKUPS_DIR"; do
        if [[ -d "$d" ]]; then
            chown "$cowner:$cowner" "$d"
            chmod o+x "$d"
        fi
    done
    [[ -d "$WEBUI_DIR" ]] && chown -R "$cowner:$cowner" "$WEBUI_DIR"
}

# Traversal (+x) bits only, on the structural LibrePortal dirs.
traversal() {
    [[ -d "$SYSTEM_DIR" ]] && chmod o+x "$SYSTEM_DIR"
    local d
    for d in "$INSTALL_DIR" "$SSL_DIR" "$SSH_DIR" "$RESTORE_DIR" "$MIGRATE_DIR"; do
        [[ -d "$d" ]] && find "$d" -maxdepth 2 -type d -exec chmod +x {} \;
    done
    _webui_bind_access
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    for d in "$CONTAINERS_DIR" "$BACKUPS_DIR"; do
        if [[ -d "$d" ]]; then
            chown "$cowner:$cowner" "$d"
            chmod o+x "$d"
        fi
    done
}

# Per-app structural perms + ownership of the LibrePortal-managed files only.
app_perms() {
    [[ -d "$CONTAINERS_DIR" ]] || return 0
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    chmod +x "$CONTAINERS_DIR" 2>/dev/null
    local app_dir app f
    for app_dir in "$CONTAINERS_DIR"/*/; do
        [[ -d "$app_dir" ]] || continue
        app="$(basename "$app_dir")"
        chmod +x "$app_dir" 2>/dev/null
        chmod o+r "$app_dir" 2>/dev/null
        find "$app_dir" -type f -name '*docker-compose*' -exec chmod o+r {} \;
        for f in migrate.txt "$app.config" docker-compose.yml "docker-compose.$app.yml"; do
            [[ -e "$app_dir$f" ]] && chown "$cowner:$cowner" "$app_dir$f"
        done
    done
}

# LibrePortal's own (regenerable) WebUI container dir -> container owner.
webui() {
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    [[ -d "$WEBUI_DIR" ]] && chown -R "$cowner:$cowner" "$WEBUI_DIR"
}

# Ensure the apps DB is manager-owned + world-readable (reclaims a stray
# root/other-owned DB; the WebUI reads it).
db_own() {
    [[ -f "$DB_PATH" ]] || return 0
    chown "$MANAGER:$MANAGER" "$DB_PATH"
    chmod o+r "$DB_PATH"
}

# Structural containers/ top dir only -> container owner + traversable.
containers_top() {
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    if [[ -d "$CONTAINERS_DIR" ]]; then
        chown "$cowner:$cowner" "$CONTAINERS_DIR"
        chmod o+x "$CONTAINERS_DIR"
    fi
}

# The backups root -> container owner + traversable (restic runs AS that user).
backups_top() {
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    if [[ -d "$BACKUPS_DIR" ]]; then
        chown "$cowner:$cowner" "$BACKUPS_DIR"
        chmod o+x "$BACKUPS_DIR"
    fi
}

# The task IPC dir -> container owner (reclaims stale manager/root-owned files).
taskdir() {
    local mode cowner; mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    [[ -d "$TASK_DIR" ]] && chown -R "$cowner:$cowner" "$TASK_DIR"
}

# Some apps' data must be owned by nobody (65534) inside the container.
app_data_nobody() {
    local d; d="$(_app_dir "${1:-}")" || return 1
    [[ -d "$d/data" ]] && chown -R 65534:65534 "$d/data"
}

# Wipe an entire app data tree, including container sub-UID dirs the
# manager / dockerinstall user can't reach (e.g. invidious/postgresdata uid
# 232070, nextcloud/html uid 33). Used by uninstall + restore-overwrite —
# both previously ran `rm -rf` via runFileOp (= as dockerinstall) and silently
# left sub-UID dirs behind, breaking reinstall + leaking storage.
# Idempotent: a missing dir is success (caller wants "ensure gone"). Refuses
# the WebUI's own slot (libreportal) — removing it would brick the WebUI.
app_data_remove() {
    local app="${1:-}"
    [[ "$app" =~ ^[A-Za-z0-9._-]+$ && "$app" != "." && "$app" != ".." ]] \
        || { echo "libreportal-ownership: invalid app name" >&2; return 1; }
    [[ "$app" == "libreportal" ]] \
        && { echo "libreportal-ownership: refusing to remove the WebUI app dir" >&2; return 1; }
    local d="$CONTAINERS_DIR/$app"
    [[ -d "$d" ]] || return 0
    rm -rf -- "$d"
}

# Chown one LibrePortal-managed file under an app dir to the container owner.
# relpath is validated: no traversal, no absolute path, safe charset only.
app_file() {
    local d rel mode cowner
    d="$(_app_dir "${1:-}")" || return 1
    rel="${2:-}"
    [[ -n "$rel" && "$rel" != /* && "$rel" != *..* && "$rel" =~ ^[A-Za-z0-9._/-]+$ ]] \
        || { echo "libreportal-ownership: invalid relpath" >&2; return 1; }
    mode="$(_mode)"; cowner="$(_container_owner "$mode")"
    [[ -e "$d/$rel" ]] && chown "$cowner:$cowner" "$d/$rel"
}

action="${1:-}"; shift 2>/dev/null || true
case "$action" in
    reconcile)        reconcile "${1:-}";;
    traversal)        traversal;;
    containers-top)   containers_top;;
    backups-top)      backups_top;;
    db-own)           db_own;;
    app-perms)        app_perms;;
    webui)            webui;;
    webui-bind)       _webui_bind_access;;
    taskdir)          taskdir;;
    app-data-nobody)  app_data_nobody "${1:-}";;
    app-data-remove)  app_data_remove "${1:-}";;
    app-file)         app_file "${1:-}" "${2:-}";;
    *) echo "usage: libreportal-ownership {reconcile [mode]|traversal|containers-top|backups-top|db-own|app-perms|webui|webui-bind|taskdir|app-data-nobody <app>|app-data-remove <app>|app-file <app> <relpath>}" >&2; exit 2;;
esac