#!/bin/bash

CACHE_DIR="cache"
COUNTRY_FILE="countries.txt"
DEFAULT_TOP=100
TOPN=$DEFAULT_TOP

mkdir -p "$CACHE_DIR"

# Parse -N flag
if [[ "$1" =~ ^-([0-9]+)$ ]]; then
    TOPN="${BASH_REMATCH[1]}"
fi

# ===========================
#   LOAD COUNTRY NAMES
# ===========================

declare -A COUNTRY_NAME
while IFS='=' read -r ISO NAME; do
    [[ -z "$ISO" ]] && continue
    COUNTRY_NAME["$ISO"]="$NAME"
done < "$COUNTRY_FILE"

# ===========================
#   SMART FETCH (ETag-based)
# ===========================

fetch_if_new() {
    local url="$1"
    local outfile="$2"
    local etagfile="${outfile}.etag"

    echo "→ Checking $outfile"
    curl -s \
        --etag-save "$etagfile" \
        --etag-compare "$etagfile" \
        -o "$outfile" \
        "$url"

    echo "  Size: $(du -h "$outfile" | cut -f1)"
}

DETAILS_JSON="$CACHE_DIR/details.json"
BANDWIDTH_JSON="$CACHE_DIR/bandwidth.json"
MERGED="$CACHE_DIR/merged.txt"

echo "=== STEP 1: Downloading (if new) ==="
fetch_if_new \
  "https://onionoo.torproject.org/details?type=relay&fields=fingerprint,country,nickname" \
  "$DETAILS_JSON"

fetch_if_new \
  "https://onionoo.torproject.org/bandwidth?type=relay&fields=fingerprint,write_history" \
  "$BANDWIDTH_JSON"

# ===========================
#   STEP 2: MERGE EVERYTHING IN ONE jq PASS
# ===========================

echo
echo "=== STEP 2: Merging in jq (single pass) ==="

jq -s -r '
  # Build index of details by fingerprint
  (.[0].relays
    | map({
        fp: .fingerprint,
        country: (.country // "??"),
        nickname: (.nickname // "UnknownRelay")
      })
    | INDEX(.fp)
  ) as $d

  # Iterate over bandwidth relays
  | .[1].relays[]
  | .fingerprint as $fp
  | ($d[$fp].country) as $cc
  | ($d[$fp].nickname) as $nick
  | (.write_history["1_month"].factor // 0) as $bw

  # Output: bw fp cc nickname
  | "\($bw) \($fp) \($cc) \($nick)"
' "$DETAILS_JSON" "$BANDWIDTH_JSON" > "$MERGED"

echo "  Merged lines: $(wc -l < "$MERGED")"

# ===========================
#   STEP 3: SORT + PRINT
# ===========================

echo
echo "=== STEP 3: Sorting and printing ==="
echo
echo "=== Top $TOPN Tor Relays (by 1-month write factor) ==="
echo

sort -nr "$MERGED" | head -n "$TOPN" | while read -r BW FP CC NICK; do
    CC_UP=$(echo "$CC" | tr '[:lower:]' '[:upper:]')
    FULL="${COUNTRY_NAME[$CC_UP]}"
    [[ -z "$FULL" ]] && FULL="$NICK"

    printf "%-40s | %12.2f | %-20s | %2s (%s)\n" "$FP" "$BW" "$NICK" "$CC_UP" "$FULL"

done

echo
echo "Done."