#!/bin/bash

# ============================================================================
# flash.sh — Flash Pico firmware for a given project
# ============================================================================
# Runs on the HOST macOS (not inside Docker) because it needs access to
# /Volumes/RPI-RP2, the USB mass storage mount that appears when the Pico
# is held in BOOTSEL mode.
#
# Usage:
#   ./flash.sh <project>
#
# Example:
#   ./flash.sh color_switcher
#
# The script finds the .uf2 file in the project's build/ directory
# automatically — no hardcoded firmware name needed.
# ============================================================================

set -e

# --- Validate arguments ---
PROJECT="${1:?Usage: ./flash.sh <project>   (e.g., ./flash.sh color_switcher)}"

# Resolve paths relative to this script's location (the repo root)
SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
BUILD_DIR="$SCRIPT_DIR/$PROJECT/build"
PICO_MOUNT="/Volumes/RPI-RP2"

# --- Find the .uf2 file ---
UF2_FILE=$(find "$BUILD_DIR" -maxdepth 1 -name "*.uf2" 2>/dev/null | head -1)

if [ -z "$UF2_FILE" ]; then
    echo "Error: No .uf2 file found in $BUILD_DIR"
    echo "  Run the build first:"
    echo "    cd $PROJECT && docker compose run --rm pico-build bash /scripts/build.sh"
    exit 1
fi

echo "Firmware: $UF2_FILE"

# --- Wait for the Pico in BOOTSEL mode ---
echo "Waiting for Pico in BOOTSEL mode ($PICO_MOUNT)..."
echo "  -> Hold BOOTSEL and plug in the Pico via USB"
while [ ! -d "$PICO_MOUNT" ]; do
    sleep 0.5
done

# --- Copy the firmware ---
echo "Pico detected. Copying $(basename "$UF2_FILE")..."
cp "$UF2_FILE" "$PICO_MOUNT/"

# --- Wait for reboot ---
echo "Waiting for Pico to reboot..."
while [ -d "$PICO_MOUNT" ]; do
    sleep 0.5
done

echo "Done! Pico rebooted with new firmware."
echo "  -> Open a serial monitor: screen /dev/tty.usbmodem* 115200"