#!/bin/bash
# ==============================================================================================
# ================================= Arr Cache Prefill ===========================================
# ==============================================================================================
#
# PURPOSE
# ─────────────────────────────────────────────────────────────────────────────
# Populates the shared tracked-data cache (see arr_get_tracked_data() in common.sh) for
# Lidarr, Sonarr, and Radarr once at array start, before any other script needs it. Without
# this, each arr's cache stays cold from boot until whichever script happens to touch that
# arr first writes through — which could be hours, depending on the daily schedule. One-shot:
# runs and exits. Originally Lidarr-only (lidarr_cache_prefill.sh, 2026-07-16), generalized
# the same day to cover all three arrs once the cache mechanism itself was generalized.
#
# ==============================================================================================
# OPERATIONAL MODEL
# ==============================================================================================
#
# Each arr's container may still be starting when this fires (array just started) — retries
# reaching that arr's API for up to ARR_PREFILL_WAIT_MINUTES before giving up on it and moving
# to the next. Not fatal if one never comes up in time; that arr's cache just stays cold until
# the next script writes through naturally, exactly as it would without this script existing.
# An arr not configured on this host (e.g. Lidarr is HOST1-only) is skipped cleanly.
#
# ==============================================================================================
# CONFIGURATION
# ==============================================================================================
#
# host*.conf
#   HOST1_LIDARR_URL / HOST1_LIDARR_API_KEY
#   HOST*_SONARR_URL / HOST*_SONARR_API_KEY
#   HOST*_RADARR_URL / HOST*_RADARR_API_KEY
#   All aliased by detect_hosts()
#
# master.conf
#   ARR_PREFILL_WAIT_MINUTES — how long to retry reaching each arr before giving up on it (default 10)
#
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$SCRIPT_DIR/../load_config.sh"

parse_args "$@"

if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root"
    exit 1
fi

if ! command -v jq >/dev/null 2>&1; then
    warn "jq not found — skipping arr cache prefill"
    exit 0
fi

acquire_lock

detect_hosts

WAIT_MINUTES="${ARR_PREFILL_WAIT_MINUTES:-10}"

# Args: arr_type, url, api_key, api_version
_prefill_one() {
    local arr_type="$1" url="$2" api_key="$3" api_version="$4"

    if [[ -z "$url" ]] || [[ -z "$api_key" ]]; then
        info "${arr_type^} not configured on $MY_ID ($LOCAL_SERVER_NAME) — nothing to prefill"
        return 0
    fi

    local waited=0
    until check_api "$url" "${arr_type^}" 5 >/dev/null 2>&1; do
        if [[ "$waited" -ge $(( WAIT_MINUTES * 60 )) ]]; then
            warn "${arr_type^} not reachable after ${WAIT_MINUTES}m — leaving cache cold, next script will write through"
            return 0
        fi
        sleep 15
        (( waited += 15 ))
    done

    local endpoint="${ARR_LIBRARY_ENDPOINT[$arr_type]:-}"
    if [[ -z "$endpoint" ]]; then
        warn "No library endpoint known for ${arr_type} — skipping"
        return 0
    fi

    local items
    items=$(arr_api "$url" "$api_key" "$api_version" "$endpoint" "${arr_type^}") || {
        warn "Could not fetch ${arr_type} library for cache prefill — leaving cache cold"
        return 0
    }

    if arr_cache_write "$arr_type" "$items"; then
        log "$ICON_DONE ${arr_type^} cache prefilled ($(echo "$items" | jq 'length') items)"
    else
        warn "Failed to write ${arr_type} cache prefill"
    fi
}

_prefill_one "lidarr" "${LIDARR_URL:-}" "${LIDARR_API_KEY:-}" "v1"
_prefill_one "sonarr" "${SONARR_URL:-}" "${SONARR_API_KEY:-}" "v3"
_prefill_one "radarr" "${RADARR_URL:-}" "${RADARR_API_KEY:-}" "v3"

exit 0