#!/bin/bash
# Usage: ~/claude-spawn-on-branch <project> <branch> <prompt> [--open]
# Creates session on branch - reuses existing worktree if one exists for the branch

set -e

PROJECT="$1"
BRANCH="$2"
PROMPT="$3"
OPEN_TAB=false
[ "$4" = "--open" ] && OPEN_TAB=true

# Normalize project name
case "$PROJECT" in
    i|integrator)
        PROJECT="integrator"
        WORKTREE_BASE=~/.worktrees/integrator
        MAIN_REPO=~/secondary_checkouts/integrator-1
        ;;
    s|splitly)
        PROJECT="splitly"
        WORKTREE_BASE=~/.worktrees/splitly
        MAIN_REPO=~/projects/SafeSplit
        ;;
    *) echo "Usage: ~/claude-spawn-on-branch <project> <branch> <prompt> [--open]"; exit 1 ;;
esac

[ -z "$BRANCH" ] || [ -z "$PROMPT" ] && { echo "Usage: ~/claude-spawn-on-branch <project> <branch> <prompt> [--open]"; exit 1; }

# Check if worktree already exists for this branch
cd "$MAIN_REPO"
git fetch origin -q

EXISTING_WORKTREE=$(git worktree list | grep "\[$BRANCH\]" | awk '{print $1}' | head -1)

if [ -n "$EXISTING_WORKTREE" ]; then
    # Reuse existing worktree - name session as <owner>-N
    OWNER_SESSION=$(basename "$EXISTING_WORKTREE")
    
    # Find next sub-session number for this worktree
    MAX_SUB=1
    for s in $(tmux list-sessions -F "#{session_name}" 2>/dev/null | grep "^${OWNER_SESSION}-[0-9]*$" | sed "s/${OWNER_SESSION}-//"); do
        [ "$s" -gt "$MAX_SUB" ] 2>/dev/null && MAX_SUB=$s
    done
    SESSION="${OWNER_SESSION}-$((MAX_SUB + 1))"

    tmux new-session -d -s "$SESSION" -c "$EXISTING_WORKTREE"
    tmux send-keys -t "$SESSION" "claude --dangerously-skip-permissions" Enter

    echo "Reusing worktree: $EXISTING_WORKTREE"
else
    # Create new session (which creates new worktree)
    output=$(~/claude-${PROJECT}-session new 2>&1)
    SESSION=$(echo "$output" | grep "^SESSION=" | cut -d= -f2)

    [ -z "$SESSION" ] && { echo "Failed to create session"; echo "$output"; exit 1; }

    cd "$WORKTREE_BASE/$SESSION" && git checkout "$BRANCH" -q && git pull origin "$BRANCH" -q 2>/dev/null || true
fi

# Open tab if requested
[ "$OPEN_TAB" = true ] && ~/open-iterm-tab "$SESSION"

# Wait for Claude prompt
for i in {1..60}; do
    if tmux capture-pane -t "$SESSION" -p 2>/dev/null | grep -q "^❯"; then
        break
    fi
    sleep 0.5
done

sleep 0.2
tmux send-keys -t "$SESSION" "$PROMPT"
sleep 0.1
tmux send-keys -t "$SESSION" Enter

echo "✓ $SESSION on $BRANCH - prompt sent"