#!/bin/sh
# Kiwix bootstrap: ensure a sample ZIM file is present, then serve it.
#
# ZIM filenames on download.kiwix.org are date-stamped and rotate monthly,
# so hard-coded URLs rot quickly. Instead this script resolves the current
# filename from the Kiwix OPDS catalog, which always points at the live file.

set -u

ZIM_DIR=/data
ZIM_FILE=devdocs_en_lit.zim
CATALOG_URL='https://library.kiwix.org/catalog/v2/entries?name=devdocs_en_lit&count=1'
MAX_ATTEMPTS=6
RETRY_DELAY=5

if ! ls "$ZIM_DIR"/*.zim >/dev/null 2>&1; then
    echo "[kiwix] No ZIM files found; resolving a sample ZIM from the Kiwix catalog..."
    attempt=0
    while [ "$attempt" -lt "$MAX_ATTEMPTS" ]; do
        attempt=$((attempt + 1))
        zim_url=$(wget -q -O - "$CATALOG_URL" 2>/dev/null \
                  | grep -o 'https://[^"]*\.zim\.meta4' | head -n1 \
                  | sed 's/\.meta4$//')
        if [ -n "$zim_url" ]; then
            echo "[kiwix] Downloading: $zim_url"
            if wget -q --timeout=60 -O "$ZIM_DIR/$ZIM_FILE" "$zim_url"; then
                echo "[kiwix] Download complete."
                break
            fi
            rm -f "$ZIM_DIR/$ZIM_FILE"
            echo "[kiwix] Download failed; retrying in ${RETRY_DELAY}s..."
        else
            echo "[kiwix] Catalog lookup failed; retrying in ${RETRY_DELAY}s..."
        fi
        sleep "$RETRY_DELAY"
    done
fi

if ls "$ZIM_DIR"/*.zim >/dev/null 2>&1; then
    echo "[kiwix] Starting kiwix-serve..."
    exec kiwix-serve --port 8080 "$ZIM_DIR"/*.zim
else
    echo "[kiwix] No ZIM files available; sleeping indefinitely."
    exec sleep infinity
fi