#!/bin/bash
# Usage: ~/send-to-session <session-name> <message>
#    or: ~/send-to-session <session-name> -f <file>
# Sends a message to a Claude agent in a tmux session and submits it.
#
# If the session is busy (Claude is thinking), waits for it to become idle
# before sending. Retries Enter if the message wasn't picked up.

SESSION="$1"
shift

if [ -z "$SESSION" ]; then
    echo "Usage: ~/send-to-session <session-name> <message>"
    echo "   or: ~/send-to-session <session-name> -f <file>"
    exit 1
fi

# Verify session exists
if ! tmux has-session -t "$SESSION" 2>/dev/null; then
    echo "Error: Session '$SESSION' does not exist"
    exit 1
fi

is_busy() {
    # Deterministic: check if the last non-empty line has a prompt (❯) or shell ($) — means idle
    local last_line=$(tmux capture-pane -t "$SESSION" -p -S -5 2>/dev/null | grep -v '^$' | tail -1)
    # Idle indicators: prompt char or permission mode line
    if echo "$last_line" | grep -qE '❯|^\$|⏵⏵|bypass permissions'; then
        return 1  # not busy
    fi
    # Active indicators: "esc to interrupt" only appears during live processing
    local output=$(tmux capture-pane -t "$SESSION" -p -S -3 2>/dev/null)
    echo "$output" | grep -qF "esc to interrupt"
}

is_processing() {
    local output=$(tmux capture-pane -t "$SESSION" -p -S -10 2>/dev/null)
    echo "$output" | grep -qE "Thinking|Roosting|Garnishing|Levitating|Baking|Whirring|Musing|Cooked|Churned|Brewed|Worked|Cogitated|Frolicking|Prestidigitating|Whisking|Mustering|Percolating|Running…|esc to interrupt|⏺"
}

has_queued_message() {
    local output=$(tmux capture-pane -t "$SESSION" -p -S -5 2>/dev/null)
    echo "$output" | grep -qE "Press up to edit queued messages"
}

# Wait for session to be idle (up to 10 minutes)
WAIT_COUNT=0
MAX_WAIT=120  # 120 * 5s = 10 minutes
while is_busy; do
    if [ $WAIT_COUNT -eq 0 ]; then
        echo "⏳ Waiting for $SESSION to finish current task..."
    fi
    WAIT_COUNT=$((WAIT_COUNT + 1))
    if [ $WAIT_COUNT -ge $MAX_WAIT ]; then
        echo "⚠ Timeout waiting for $SESSION to become idle. Sending anyway."
        break
    fi
    sleep 5
done

# Clear any partial input
tmux send-keys -t "$SESSION" C-u
sleep 0.2

# Send the message
send_message() {
    if [ "$1" = "-f" ]; then
        local file="$2"
        if [ ! -f "$file" ]; then
            echo "Error: File not found: $file"
            exit 1
        fi
        tmux load-buffer "$file"
        tmux paste-buffer -t "$SESSION"
    else
        local msg="$*"
        if echo "$msg" | grep -q $'\n' || [ ${#msg} -gt 200 ]; then
            local tmpfile=$(mktemp /tmp/send-to-session-XXXXXX.txt)
            printf '%s' "$msg" > "$tmpfile"
            tmux load-buffer "$tmpfile"
            tmux paste-buffer -t "$SESSION"
            rm -f "$tmpfile"
        else
            tmux send-keys -t "$SESSION" "$msg"
        fi
    fi
}

send_message "$@"
sleep 0.3
tmux send-keys -t "$SESSION" Enter

# Verify it's processing, retry Enter if needed
for attempt in 1 2 3; do
    sleep 2
    if is_processing; then
        echo "✓ Message sent and processing"
        exit 0
    fi
    # Check if message is sitting in queue (Claude was still wrapping up)
    if has_queued_message; then
        echo "✓ Message queued (session is finishing previous task)"
        exit 0
    fi
    # Message might be in input buffer — retry Enter
    if [ $attempt -lt 3 ]; then
        tmux send-keys -t "$SESSION" Enter
        sleep 1
    fi
done

echo "⚠ Message sent - could not confirm it was received"