run.sh

#!/usr/bin/env bash

# Wrapper around zellij run that adds move-or-create behavior for directional panes
# Usage: run.sh [OPTIONS] -- <command> [args...]
#
# Accepts all zellij run options. Key options:
#   --floating              Open in a floating pane
#   --direction <dir>       Open in direction (up, down, left, right)
#   --close-on-exit         Close pane when command exits
#   --name <name>          Name the pane
#   --cwd <path>           Set working directory
#
# For --direction, will reuse existing pane if one exists in that direction,
# otherwise creates a new pane.
#
# Caches the last command per-directory for rerun functionality.

set -e

# Cache the command for rerun functionality
CACHE_DIR="/tmp/helix_last_command_$USER"
mkdir -p "$CACHE_DIR"
# Use PWD hash for per-directory caching (portable across macOS and Linux)
if command -v md5sum &> /dev/null; then
    PWD_HASH=$(echo -n "$PWD" | md5sum | cut -d' ' -f1)
elif command -v md5 &> /dev/null; then
    PWD_HASH=$(echo -n "$PWD" | md5)
else
    # Fallback: use base64-encoded path (less elegant but works everywhere)
    PWD_HASH=$(echo -n "$PWD" | base64 | tr -d '=\n' | tr '/' '_')
fi
CACHE_FILE="$CACHE_DIR/$PWD_HASH"

# Save all args and PWD to cache file
cache_command() {
    {
        echo "PWD=$PWD"
        echo -n "ARGS=("
        printf '%q ' "$@"
        echo ")"
    } > "$CACHE_FILE"
}

# Cache the command with all original arguments
cache_command "$@"

# Parse args to find --floating or --direction
is_floating=false
direction=""
remaining_args=()

while [ "$#" -gt 0 ]; do
    case "$1" in
        --floating|-f)
            is_floating=true
            remaining_args+=("$1")
            shift
            ;;
        --direction|-d)
            direction="$2"
            remaining_args+=("$1" "$2")
            shift 2
            ;;
        *)
            remaining_args+=("$1")
            shift
            ;;
    esac
done

# For floating, add default size/position if not specified, then delegate to zellij run
if [ "$is_floating" = true ]; then
    # Check if user specified dimensions/position
    has_width=false
    has_height=false
    has_x=false
    has_y=false
    for arg in "${remaining_args[@]}"; do
        case "$arg" in
            --width) has_width=true ;;
            --height) has_height=true ;;
            --x|-x) has_x=true ;;
            --y|-y) has_y=true ;;
        esac
    done

    # Build default args for large centered floating pane (90% width/height, centered at 5%/5%)
    default_args=()
    [ "$has_width" = false ] && default_args+=(--width "90%")
    [ "$has_height" = false ] && default_args+=(--height "90%")
    [ "$has_x" = false ] && default_args+=(--x "5%")
    [ "$has_y" = false ] && default_args+=(--y "5%")

    exec zellij run --cwd "$PWD" "${default_args[@]}" "${remaining_args[@]}"
fi

# If no direction specified, delegate to zellij run (it will pick best location)
if [ -z "$direction" ]; then
    exec zellij run --cwd "$PWD" "${remaining_args[@]}"
fi

# For directional targets, implement move-or-create behavior
# Get current focused pane ID before moving
pane_before=$(zellij action list-clients | tail -n +2 | head -n 1 | awk '{print $2}')

# Try to move in the specified direction
zellij action move-focus "$direction"

# Get focused pane ID after moving
pane_after=$(zellij action list-clients | tail -n +2 | head -n 1 | awk '{print $2}')

# Remove --direction from remaining_args since we'll replace it
final_args=()
skip_next=false
for arg in "${remaining_args[@]}"; do
    if [ "$skip_next" = true ]; then
        skip_next=false
        continue
    fi
    if [ "$arg" = "--direction" ] || [ "$arg" = "-d" ]; then
        skip_next=true
        continue
    fi
    final_args+=("$arg")
done

# If pane IDs are different, we moved to an existing pane - write command to it
# If same, create new pane in that direction
# NOTE: --close-on-exit and other zellij run flags only affect newly created panes.
# Existing panes retain their original behavior regardless of flags passed to this script.
if [ "$pane_before" != "$pane_after" ]; then
    # Existing pane - extract the command after "--" and write it
    # Find the command after "--"
    found_separator=false
    command_parts=()
    for arg in "${final_args[@]}"; do
        if [ "$found_separator" = true ]; then
            command_parts+=("$arg")
        elif [ "$arg" = "--" ]; then
            found_separator=true
        fi
    done

    # Build the command string
    command_str="${command_parts[*]}"

    # Write command to the existing pane
    zellij action write-chars "cd '$PWD' && $command_str"
    zellij action write 13  # Send enter
else
    # No pane exists - create new one
    exec zellij run --direction "$direction" --cwd "$PWD" "${final_args[@]}"
fi