#!/usr/bin/env bash
# Download Bunny.net access logs and produce a capability frequency report.
#
# This is the only way to see CDN-cached request frequency — the origin
# Prometheus metrics only see cache misses. A weekly cron run pushing the
# output to Grafana covers >99% of analysis needs without real-time overhead.
#
# What this script answers:
#   - Which capabilities are queried most often (all requests, including hits)?
#   - Which device class / protocol combinations are active?
#   - What is the cache hit ratio per endpoint?
#   - Which full query string combinations are most common?
#
# Usage:
#   BUNNYNET_API_KEY=your-key PULL_ZONE_ID=12345 ./scripts/query-report.sh
#   BUNNYNET_API_KEY=your-key PULL_ZONE_ID=12345 DAYS=30 ./scripts/query-report.sh
#
# Output:
#   Human-readable report to stdout.
#   With PROMETHEUS_PUSH_URL set, also pushes counters to a Prometheus
#   Pushgateway (e.g. your dedicated analytics Grafana stack) so the weekly
#   numbers become a time-series rather than a point-in-time dump.
#
#   PROMETHEUS_PUSH_URL=https://pushgateway.your-grafana.example/metrics/job/apix-cdn-report \
#   BUNNYNET_API_KEY=your-key PULL_ZONE_ID=12345 ./scripts/query-report.sh
#
# Prerequisites: curl, gzip, awk (any POSIX awk)

set -euo pipefail

BUNNYNET_API_KEY="${BUNNYNET_API_KEY:?BUNNYNET_API_KEY is required}"
PULL_ZONE_ID="${PULL_ZONE_ID:-$(cat .bunnynet-pull-zone-id 2>/dev/null || echo '')}"
PULL_ZONE_ID="${PULL_ZONE_ID:?PULL_ZONE_ID is required (or run setup-bunnynet.sh first)}"
DAYS="${DAYS:-7}"
PROMETHEUS_PUSH_URL="${PROMETHEUS_PUSH_URL:-}"
LOGGING_BASE="https://logging.bunnycdn.com"

WORK=$(mktemp -d)
trap 'rm -rf "$WORK"' EXIT

touch "${WORK}/combined.log"

# ── 1. Download logs ──────────────────────────────────────────────────────────

echo "==> Downloading Bunny.net access logs — pull zone ${PULL_ZONE_ID}, last ${DAYS} days ..."

for i in $(seq 1 "$DAYS"); do
    # Support both GNU date (Linux) and BSD date (macOS)
    if date --version >/dev/null 2>&1; then
        DATE=$(date -d "-${i} days" +%Y/%m/%d)
    else
        DATE=$(date -v "-${i}d" +%Y/%m/%d)
    fi
    Y=$(echo "$DATE" | cut -d/ -f1)
    M=$(echo "$DATE" | cut -d/ -f2)
    D=$(echo "$DATE" | cut -d/ -f3)

    GZ="${WORK}/${Y}-${M}-${D}.gz"
    STATUS=$(curl -s -o "$GZ" -w "%{http_code}" \
        -H "AccessKey: ${BUNNYNET_API_KEY}" \
        "${LOGGING_BASE}/${Y}/${M}/${D}/${PULL_ZONE_ID}/")

    if [ "$STATUS" = "200" ] && [ -s "$GZ" ]; then
        gunzip -c "$GZ" >> "${WORK}/combined.log"
        printf "    %s-%s-%s  OK\n" "$Y" "$M" "$D"
    else
        printf "    %s-%s-%s  no data (HTTP %s)\n" "$Y" "$M" "$D" "$STATUS"
    fi
done

if [ ! -s "${WORK}/combined.log" ]; then
    echo ""
    echo "No log data found for the requested period."
    exit 0
fi

# ── 2. Isolate search requests ────────────────────────────────────────────────

grep -E '"GET /services\?' "${WORK}/combined.log"   > "${WORK}/svc.log"          || true
grep -E '"GET /devices\?'  "${WORK}/combined.log"   > "${WORK}/dev.log"          || true
grep -E '"GET /devices\?|"GET /services\?' "${WORK}/combined.log" > "${WORK}/search.log" || true
grep -E '"GET /[^"?]+/replacements\?' "${WORK}/combined.log" > "${WORK}/repl.log" || true

TOTAL=$(wc -l < "${WORK}/combined.log")
SEARCH=$(wc -l < "${WORK}/search.log")

echo ""
printf "Total log entries  : %d\n" "$TOTAL"
printf "Search requests    : %d  (GET /services + GET /devices)\n" "$SEARCH"
echo ""

# ── Helper: extract query string from a log line ──────────────────────────────
# Input line:  1.2.3.x - - [date] "GET /services?capability=nlp HTTP/1.1" 200 … HIT
# Output:      capability=nlp

extract_qs() {
    awk '{
        if (match($0, /"GET [^?]+"?\?([^" ]+) HTTP/, arr)) print arr[1]
    }' "$1"
}

extract_param() {
    local param="$1" file="$2"
    extract_qs "$file" | tr "&" "\n" | grep "^${param}=" | cut -d= -f2-
}

# ── 3. Cache hit ratio ────────────────────────────────────────────────────────

echo "=== Cache hit ratio (search endpoints) ==================================="
HITS=$(awk '$NF=="HIT"'    "${WORK}/search.log" | wc -l || echo 0)
MISS=$(awk '$NF=="MISS"'   "${WORK}/search.log" | wc -l || echo 0)
BYPS=$(awk '$NF=="BYPASS"' "${WORK}/search.log" | wc -l || echo 0)
printf "  HIT     : %d\n" "$HITS"
printf "  MISS    : %d\n" "$MISS"
printf "  BYPASS  : %d\n" "$BYPS"
echo ""

# ── 4. Top capabilities ───────────────────────────────────────────────────────

echo "=== Top capabilities  GET /services ======================================"
extract_param "capability" "${WORK}/svc.log" \
    | sort | uniq -c | sort -rn | head -20 \
    | awk '{printf "  %7d  %s\n", $1, $2}'
echo ""

echo "=== Top capabilities  GET /devices ======================================="
extract_param "capability" "${WORK}/dev.log" \
    | sort | uniq -c | sort -rn | head -20 \
    | awk '{printf "  %7d  %s\n", $1, $2}'
echo ""

# ── 5. Device class and protocol ─────────────────────────────────────────────

echo "=== Device class breakdown ================================================"
extract_param "deviceClass" "${WORK}/search.log" \
    | sort | uniq -c | sort -rn | head -10 \
    | awk '{printf "  %7d  %s\n", $1, $2}'
echo ""

echo "=== Protocol breakdown ===================================================="
extract_param "protocol" "${WORK}/search.log" \
    | sort | uniq -c | sort -rn | head -10 \
    | awk '{printf "  %7d  %s\n", $1, $2}'
echo ""

# ── 6. Stage breakdown (services) — canonical form omits PRODUCTION ───────────

echo "=== Stage breakdown  GET /services (explicit only) ======================="
echo "  Note: requests without ?stage= are PRODUCTION (canonical form omits it)"
extract_param "stage" "${WORK}/svc.log" \
    | sort | uniq -c | sort -rn \
    | awk '{printf "  %7d  %s\n", $1, $2}'
IMPLICIT_PROD=$(extract_qs "${WORK}/svc.log" | grep -vc "stage=" || true)
printf "  %7d  PRODUCTION (implicit)\n" "$IMPLICIT_PROD"
echo ""

# ── 7. Top full query string combinations ────────────────────────────────────

echo "=== Top 30 query string combinations ====================================="
extract_qs "${WORK}/search.log" \
    | sort | uniq -c | sort -rn | head -30 \
    | awk '{printf "  %7d  ?%s\n", $1, $2}'
echo ""

echo "=== Replacements endpoint top parameters ================================="
if [ -s "${WORK}/repl.log" ]; then
    extract_qs "${WORK}/repl.log" \
        | sort | uniq -c | sort -rn | head -10 \
        | awk '{printf "  %7d  ?%s\n", $1, $2}'
else
    echo "  (no replacement requests in period)"
fi
echo ""

# ── 8. Push to Prometheus Pushgateway (optional) ─────────────────────────────
#
# Pushes capability counters as Prometheus metrics so they appear as a
# time-series in the dedicated analytics Grafana instance.
# Run weekly via cron to build a trend chart without real-time overhead.

if [ -n "$PROMETHEUS_PUSH_URL" ]; then
    echo "==> Pushing counters to Prometheus Pushgateway ..."

    {
        echo "# HELP apix_cdn_capability_requests_total Capability search requests (all, including CDN cache hits)"
        echo "# TYPE apix_cdn_capability_requests_total counter"

        extract_param "capability" "${WORK}/svc.log" \
            | sort | uniq -c \
            | awk '{printf "apix_cdn_capability_requests_total{resource=\"services\",capability=\"%s\"} %d\n", $2, $1}'

        extract_param "capability" "${WORK}/dev.log" \
            | sort | uniq -c \
            | awk '{printf "apix_cdn_capability_requests_total{resource=\"devices\",capability=\"%s\"} %d\n", $2, $1}'

        echo "# HELP apix_cdn_cache_requests_total CDN cache disposition for search endpoints"
        echo "# TYPE apix_cdn_cache_requests_total counter"
        printf "apix_cdn_cache_requests_total{status=\"hit\"} %d\n"    "$HITS"
        printf "apix_cdn_cache_requests_total{status=\"miss\"} %d\n"   "$MISS"
        printf "apix_cdn_cache_requests_total{status=\"bypass\"} %d\n" "$BYPS"

        echo "# HELP apix_cdn_deviceclass_requests_total Device class breakdown"
        echo "# TYPE apix_cdn_deviceclass_requests_total counter"
        extract_param "deviceClass" "${WORK}/search.log" \
            | sort | uniq -c \
            | awk '{printf "apix_cdn_deviceclass_requests_total{deviceClass=\"%s\"} %d\n", $2, $1}'

        echo "# HELP apix_cdn_protocol_requests_total Protocol breakdown"
        echo "# TYPE apix_cdn_protocol_requests_total counter"
        extract_param "protocol" "${WORK}/search.log" \
            | sort | uniq -c \
            | awk '{printf "apix_cdn_protocol_requests_total{protocol=\"%s\"} %d\n", $2, $1}'

    } | curl -sf --data-binary @- "${PROMETHEUS_PUSH_URL}" && \
        echo "    Done." || echo "    WARNING: Pushgateway push failed (non-fatal)."

    echo ""
fi

# ── 9. Summary ────────────────────────────────────────────────────────────────

echo "Report complete."
printf "Period     : last %d days\n" "$DAYS"
printf "Pull zone  : %s\n" "$PULL_ZONE_ID"
[ -n "$PROMETHEUS_PUSH_URL" ] && echo "Pushed to  : ${PROMETHEUS_PUSH_URL}"