#   ESP32 SvelteKit --
#
#   A simple, secure and extensible framework for IoT projects for ESP32 platforms
#   with responsive Sveltekit front-end built with TailwindCSS and DaisyUI.
#   https://github.com/theelims/ESP32-sveltekit
#
#   Copyright (C) 2018 - 2023 rjwats
#   Copyright (C) 2023 theelims
#   Copyright (C) 2023 Maxtrium B.V. [ code available under dual license ]
#   Copyright (C) 2024 runeharlyk
#
#   All Rights Reserved. This software may be modified and distributed under
#   the terms of the LGPL v3 license. See the LICENSE file for details.

from pathlib import Path
from shutil import copytree, rmtree, copyfileobj
from os.path import exists, getmtime
import os
import gzip
import mimetypes
import glob
from datetime import datetime

Import("env")

project_dir = env["PROJECT_DIR"]
buildFlags = env.ParseFlags(env["BUILD_FLAGS"])

interface_dir = project_dir + "/../app"
output_file = project_dir + "/lib/ESP32-sveltekit/WWWData.h"
source_www_dir = interface_dir + "/src"
build_dir = interface_dir + "/build"
filesystem_dir = project_dir + "/data/www"


def find_latest_timestamp_for_app():
    return max(
        (getmtime(f) for f in glob.glob(f"{source_www_dir}/**/*", recursive=True))
    )


def should_regenerate_output_file():
    if not flag_exists("EMBED_WWW") or not exists(output_file):
        return True
    last_source_change = find_latest_timestamp_for_app()
    last_build = getmtime(output_file)

    print(
        f"Newest file: {datetime.fromtimestamp(last_source_change)}, output file: {datetime.fromtimestamp(last_build)}"
    )

    return last_build < last_source_change


def gzip_file(file):
    with open(file, 'rb') as f_in:
        with gzip.open(file + '.gz', 'wb') as f_out:
            copyfileobj(f_in, f_out)
    os.remove(file)

def flag_exists(flag):
    for define in buildFlags.get("CPPDEFINES"):
        if (define == flag or (isinstance(define, list) and define[0] == flag)):
            return True
    return False


def get_package_manager():
    if exists(os.path.join(interface_dir, "pnpm-lock.yaml")):
        return "pnpm"
    if exists(os.path.join(interface_dir, "yarn.lock")):
        return "yarn"
    if exists(os.path.join(interface_dir, "package-lock.json")):
        return "npm"


def build_webapp():
    if package_manager := get_package_manager():
        print(f"Building interface with {package_manager}")
        os.chdir(interface_dir)
        env.Execute(f"{package_manager} install")
        env.Execute(f"{package_manager} run build")
        os.chdir("..")
    else:
        raise Exception(
            "No lock-file found. Please install dependencies for interface (eg. npm install)"
        )


def embed_webapp():
    if flag_exists("EMBED_WWW"):
        print("Converting interface to PROGMEM")
        build_progmem()
        return
    add_app_to_filesystem()


def build_progmem():
    mimetypes.init()
    with open(output_file, "w") as progmem:
        progmem.write("#include <functional>\n")
        progmem.write("#include <Arduino.h>\n")

        assetMap = {}

        for idx, path in enumerate(Path(build_dir).rglob("*.*")):
            asset_path = path.relative_to(build_dir).as_posix()
            asset_mime = (
                mimetypes.guess_type(asset_path)[0] or "application/octet-stream"
            )
            print(f"Converting {asset_path}")

            asset_var = f"ESP_SVELTEKIT_DATA_{idx}"
            progmem.write(f"// {asset_path}\n")
            progmem.write(f"const uint8_t {asset_var}[] PROGMEM = {{\n\t")
            file_data = gzip.compress(path.read_bytes())

            for i, byte in enumerate(file_data):
                if i and not (i % 16):
                    progmem.write("\n\t")
                progmem.write(f"0x{byte:02X},")

            progmem.write("\n};\n\n")
            assetMap[asset_path] = {
                "name": asset_var,
                "mime": asset_mime,
                "size": len(file_data),
            }

        progmem.write(
            "typedef std::function<void(const String& uri, const String& contentType, const uint8_t * content, size_t len)> RouteRegistrationHandler;\n\n"
        )
        progmem.write("class WWWData {\n")
        progmem.write("\tpublic:\n")
        progmem.write(
            "\t\tstatic void registerRoutes(RouteRegistrationHandler handler) {\n"
        )

        for asset_path, asset in assetMap.items():
            progmem.write(
                f'\t\t\thandler("/{asset_path}", "{asset["mime"]}", {asset["name"]}, {asset["size"]});\n'
            )

        progmem.write("\t\t}\n")
        progmem.write("};\n\n")


def add_app_to_filesystem():
    build_path = Path(build_dir)
    www_path = Path(filesystem_dir)
    if www_path.exists() and www_path.is_dir():
        rmtree(www_path)
    print("Copying and compress app to data directory")
    copytree(build_path, www_path)
    for current_path, _, files in os.walk(www_path):
        for file in files:
            gzip_file(os.path.join(current_path, file))
    print("Build LittleFS file system image and upload to ESP32")
    env.Execute("pio run --target uploadfs")


print("running: build_app.py")
if should_regenerate_output_file():
    build_webapp()
    embed_webapp()
