#!/bin/bash
set -euo pipefail

# ---------------------------------------------
# Konfiguracja
# ---------------------------------------------
#SUBREDDITS=("classicusenet" "polska")            # lista śledzonych subredditów
SUBREDDITS=("polska")            # lista śledzonych subredditów
BASE="/home/ppp/poczta/reddit"                  # wspólna baza Maildirów
UA="Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0 Safari/537.36"

mkdir -p "$BASE"

echo "[INFO] Start. Subreddity: ${SUBREDDITS[*]}"

# -------------------------------------------------
fetch() {
  local url="$1" outfile="$2"
  echo "[INFO] Pobieram: $url"
  curl -f -s -A "$UA" "$url" -o "$outfile"
  sleep $(( RANDOM % 1 + 2 ))
}

# -------------------------------------------------
emit() {
  local id="$1" parent="$2" subject="$3" author="$4" date_rfc="$5" body="$6" maildir="$7"

  local fname="${id}.reddit:2,"
  for dir in cur new tmp; do
    [[ -e "$maildir/$dir/$fname" ]] && { echo "[INFO] Pomijam duplikat $id"; return; }
  done

  local tmpfile="$maildir/tmp/$fname"
  local newfile="$maildir/new/$fname"

  echo "[INFO] Zapisuję msg $id ($subject)"

  {
    echo "From: $author <$author@reddit.com>"
    echo "Subject: $subject"
    echo "Date: $date_rfc"
    echo "Message-ID: <$id@reddit.com>"
    [[ -n "$parent" ]] && {
      echo "In-Reply-To: <$parent@reddit.com>"
      echo "References: <$parent@reddit.com>"
    }
    echo "Content-Type: text/plain; charset=UTF-8"
    echo
    echo "$body" | while IFS= read -r line; do
  if grep -qE 'https?://\S+' <<<"$line"; then
    echo "$line"
  else
    echo "$line" | fold -s -w72
  fi
done
  } >"$tmpfile"

  mv "$tmpfile" "$newfile"
}

# -------------------------------------------------
walk_comments() {
  local comments_json="$1" parent_id="$2" subject_top="$3" maildir="$4"
  [[ "$comments_json" == "\"\"" || "$comments_json" == "null" ]] && return

  jq -c '.data.children[] | select(.kind=="t1")' <<<"$comments_json" |
  while IFS= read -r cm; do
    cid=$(jq -r '.data.id' <<<"$cm")
    author=$(jq -r '.data.author' <<<"$cm")
    body=$(jq -r '.data.body' <<<"$cm")
    ts=$(jq -r '.data.created_utc' <<<"$cm")
    date_rfc=$(date -u -d @"$ts" -R)

    emit "$cid" "$parent_id" "Re: $subject_top" "$author" "$date_rfc" "$body" "$maildir"

    repl=$(jq -c '.data.replies' <<<"$cm")
    walk_comments "$repl" "$cid" "$subject_top" "$maildir"
  done
}

# -------------------------------------------------
# Główna pętla
# -------------------------------------------------
for sub in "${SUBREDDITS[@]}"; do
  echo "[INFO] ---- Subreddit /r/$sub ----"
  MAILDIR="$BASE/$sub"
  mkdir -p "$MAILDIR"/{cur,new,tmp}

  tmp_json=$(mktemp)
  trap 'rm -f "$tmp_json"' RETURN

  fetch "https://www.reddit.com/r/$sub.json" "$tmp_json" || { echo "[WARN] Nie udało się pobrać listingu $sub"; continue; }

  jq -c '.data.children[] | select(.kind=="t3")' "$tmp_json" |
  while IFS= read -r post; do
    subject_top=$(jq -r '.data.title' <<<"$post")
    pid=$(jq -r '.data.id' <<<"$post")
    echo "[INFO] Wątek: \"$subject_top\" (ID: $pid)"

    author=$(jq -r '.data.author' <<<"$post")
    ts=$(jq -r '.data.created_utc' <<<"$post")
    date_rfc=$(date -u -d @"$ts" -R)

    body=$(jq -r '.data.selftext' <<<"$post")
    [[ -z "$body" ]] && body=$(jq -r '.data.crosspost_parent_list[0].selftext // empty' <<<"$post")
    [[ -z "$body" ]] && body=$(jq -r '.data.url_overridden_by_dest // .data.url // ""' <<<"$post")

    emit "$pid" "" "$subject_top" "$author" "$date_rfc" "$body" "$MAILDIR"

    thread_json=$(mktemp)
    fetch "https://www.reddit.com/r/$sub/comments/$pid.json" "$thread_json" || { rm -f "$thread_json"; continue; }
    comments_part=$(jq -c '.[1]' "$thread_json")
    walk_comments "$comments_part" "$pid" "$subject_top" "$MAILDIR"
    rm -f "$thread_json"
  done

done

echo "[INFO] Zakończono."