#!/usr/bin/env bash
# Usage: set-topic.sh <cwd> <topic text>
# Finds the session ID for the given cwd and writes the topic file

set -euo pipefail

CWD="$1"
shift
TOPIC="$*"

HASH=$(echo -n "$CWD" | md5sum | cut -d' ' -f1)
SESSION_FILE="/tmp/claude-session-id-$HASH"

# If running inside tmux, mirror the topic into the tmux status bar:
# session name = project part (before ':'), @claude_topic = full topic.
if [[ -n "${TMUX:-}" ]]; then
    PROJECT="${TOPIC%%:*}"
    # tmux session names may not contain ':' or '.'
    PROJECT=$(echo "$PROJECT" | tr ':.' '--' | cut -c1-30)
    tmux rename-session "$PROJECT" 2>/dev/null || true
    tmux set -q @claude_topic "$TOPIC" 2>/dev/null || true
fi

if [[ ! -f "$SESSION_FILE" ]]; then
    # Session ID file doesn't exist yet — the statusline hook hasn't run.
    # Write the topic to a pending file so statusline.sh can pick it up
    # on its first run for this cwd.
    PENDING_FILE="/tmp/claude-pending-topic-$HASH"
    echo "$TOPIC" > "$PENDING_FILE"
    echo "Topic queued (session ID not yet available). Will be applied after next response."
    exit 0
fi

SESSION_ID=$(cat "$SESSION_FILE")
TOPIC_DIR="$HOME/.claude/status/$SESSION_ID"
mkdir -p "$TOPIC_DIR"
echo "$TOPIC" > "$TOPIC_DIR/claude-topic.txt"
echo "Topic set for session $SESSION_ID: $TOPIC"