#!/usr/bin/env bash
# Shared by the watcher and recovery helper. Config is trusted user-owned Bash.

log() {
    printf '%s: %s\n' "$LOGTAG" "$*" >&2
}

# These settings are consumed by scripts sourcing this library and via ${!name}.
# shellcheck disable=SC2034
load_config() {
    MONITOR=HDMI-A-2
    DEBOUNCE_SECONDS=30
    HDMI_SETTLE_SECONDS=5
    VT_SWITCH_DELAY_SECONDS=1
    VT_RETURN_SETTLE_SECONDS=2
    local config="${XDG_CONFIG_HOME:-$HOME/.config}/revive-monitor/config.env"
    if [[ -r "$config" ]]; then
        # shellcheck disable=SC1090
        source "$config" || return 1
    fi
    if [[ ! "$MONITOR" =~ ^[a-zA-Z0-9_-]+$ ]]; then
        log 'Invalid MONITOR: expected an output name such as HDMI-A-2'
        return 1
    fi
    local name value limit
    for name in DEBOUNCE_SECONDS HDMI_SETTLE_SECONDS VT_SWITCH_DELAY_SECONDS VT_RETURN_SETTLE_SECONDS; do
        value="${!name}"
        limit=300
        [[ "$name" == DEBOUNCE_SECONDS ]] && limit=3600
        if [[ ! "$value" =~ ^[0-9]{1,4}$ ]] || (( 10#$value > limit )); then
            log "Invalid $name: expected an integer between 0 and $limit"
            return 1
        fi
        printf -v "$name" '%d' "$((10#$value))"
    done
}

require_commands() {
    local command_name
    for command_name in "$@"; do
        if ! command -v "$command_name" >/dev/null 2>&1; then
            log "Required command not found: $command_name"
            return 1
        fi
    done
}

prepare_runtime() {
    # No shared /tmp fallback: locks must live in a private per-user directory.
    local runtime="${XDG_RUNTIME_DIR:-}"
    if [[ "$runtime" != /* || ! -d "$runtime" || -L "$runtime" || ! -O "$runtime" ]] ||
        [[ "$(stat -c %a -- "$runtime" 2>/dev/null)" != 700 ]]; then
        log 'XDG_RUNTIME_DIR must be an existing, user-owned directory with mode 0700'
        return 1
    fi
    STATE_DIR="$runtime/revive-monitor"
    if [[ -L "$STATE_DIR" ]]; then
        log 'Refusing a symlink as runtime state directory'
        return 1
    fi
    (umask 077; mkdir -p -- "$STATE_DIR") || return 1
    if [[ ! -O "$STATE_DIR" || "$(stat -c %a -- "$STATE_DIR")" != 700 ]]; then
        log 'Runtime state directory must be user-owned with mode 0700'
        return 1
    fi
}

get_active_wayland_session() {
    local sessions sid rest properties key value uid type active vt seat desktop
    sessions="$(timeout 5 loginctl list-sessions --no-legend --no-pager 2>/dev/null)" || return 1
    while read -r sid rest; do
        [[ -n "$sid" ]] || continue
        properties="$(timeout 5 loginctl show-session "$sid" -p User -p Type -p Active -p VTNr -p Seat -p Desktop 2>/dev/null)" || continue
        uid='' type='' active='' vt='' seat='' desktop=''
        while IFS='=' read -r key value; do
            case "$key" in
                User) uid="$value" ;;
                Type) type="$value" ;;
                Active) active="$value" ;;
                VTNr) vt="$value" ;;
                Seat) seat="$value" ;;
                Desktop) desktop="${value,,}" ;;
            esac
        done <<< "$properties"
        [[ "$uid" == "$UID" && "$type" == wayland && "$active" == yes && "$seat" == seat0 ]] || continue
        [[ -z "$desktop" || "$desktop" == *hyprland* ]] || continue
        if [[ "$vt" =~ ^[1-9][0-9]?$ ]] && (( vt <= 63 )); then
            printf '%s:%s\n' "$sid" "$vt"
            return 0
        fi
    done <<< "$sessions"
    return 1
}