from urllib.parse import unquote

import mimetypes
import datetime
import aiofiles
import asyncio
import config
import os

STATUS = {
    200: "200 OK",
    403: "403 Forbidden",
    404: "404 Not Found",
    405: "405 Method Not Allowed",
    418: "418 I'm a teapot"
}

class WebServer:
    async def log(self, text: str, addr: tuple=None, file: str=None) -> None:
        text = text.replace("<ADDR>", f"{addr[0]}:{addr[1]}" if addr else "")
        text = text.replace("<FILE>", file if file else "")

        if config.log_file:
            async with aiofiles.open(config.log_file, mode="a") as file:
                await file.write(text + "\n")
        else:
            print(text)


    async def send_headers(self, writer: asyncio.StreamWriter, status: int, file_size: int, mime: str="text/html; charset=utf-8") -> None:
        headers = (
            f"HTTP/1.1 {STATUS[status]}\r\n"
            f"Content-Type: {mime}\r\n"
            f"Content-Length: {file_size}\r\n"
            f"Server: {config.name}\r\n"
            "\r\n"
        )

        writer.write(headers.encode())
        await writer.drain()
        

    async def send_file(self, writer: asyncio.StreamWriter, file_path: str, file_size: int):
        if not os.path.isfile(file_path):
            writer.write("file error")
            await writer.drain()

        sent = 0
        async with aiofiles.open(file_path, "rb") as f:
            while sent < file_size:
                chunk = await f.read(config.write_buffer)
                if not chunk: break

                writer.write(chunk)
                await writer.drain()

                sent += len(chunk)


    async def handle(self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
        addr = writer.get_extra_info("peername")
        await self.log(config.conn_msg, addr)
        rdata = await reader.read(config.read_buffer)
        data = rdata.decode()

        if not data: return

        real_addr = None
        for line in data.split("\n"):
            if line.startswith("X-Real-IP: "):
                real_addr = line[len("X-Real-IP: "):].strip()
                break

        if real_addr and config.proxied:
            addr = (real_addr, addr[1])

        request = data.split("\n")[0]
        parts = request.split()
        if len(parts) < 2: return

        path = unquote(parts[1])
        file_name = path[1:] if path.startswith('/') else path
        file_path = os.path.abspath(os.path.join(config.directory, file_name))

        if not file_path.startswith(os.path.abspath(config.directory)):
            await self.log(config.err_msgs[418], addr, file_path)
            file_size = os.path.getsize(config.err_files[418])
            await self.send_headers(writer, 418, file_size)
            await self.send_file(writer, config.err_files[418], file_size)

            writer.close()
            await writer.wait_closed()
            return


        if os.path.isfile(file_path):
            mime, _ = mimetypes.guess_type(file_path)
            file_size = os.path.getsize(file_path)
            if not mime: mime = "application/octet-stream"
            if mime.startswith("text"): mime += "; charset=utf-8"

            await self.send_headers(writer, 200, file_size, mime)
            await self.send_file(writer, file_path, file_size)


        elif os.path.isdir(file_path):
            resp = ""
            async with aiofiles.open(config.preset_file, "r", encoding="utf-8") as f:
                resp = await f.read()

            files = ""
            base_path = os.path.relpath(file_path, config.directory).replace('\\', '/')
            if base_path == '.':
                base_path = ''
            
            for item in sorted(os.listdir(file_path)):
                item_path = os.path.join(file_path, item)
                is_dir = os.path.isdir(item_path)
                
                if base_path: rel_path = f"{base_path}/{item}"
                else: rel_path = item
                
                if is_dir:
                    rel_path += "/"
                    item += "/"
                
                modify_time = os.path.getmtime(item_path)
                modify_datetime = datetime.datetime.fromtimestamp(modify_time)
                formatted_time = modify_datetime.strftime("%d.%m.%Y %H:%M:%S")
                
                rel_path_encoded = rel_path.replace(' ', '%20').replace('#', '%23')
                
                files += f'<a class={"dir" if is_dir else "file"} href="/{rel_path_encoded}">{item}</a> | {formatted_time}<br>\n'

            resp = resp.replace("<FILES>", files)
            resp = resp.encode()

            await self.send_headers(writer, 200, len(resp))

            writer.write(resp)
            await writer.drain()


        else:
            await self.log(config.err_msgs[404], addr, config.err_files[404])
            file_size = os.path.getsize(config.err_files[404])
            await self.send_headers(writer, 404, file_size)
            await self.send_file(writer, config.err_files[404], file_size)

            writer.close()
            await writer.wait_closed()

            return

        await self.log(config.get_msg, addr, file_path)
        writer.close()
        await writer.wait_closed()


    async def start(self) -> None:
        server = await asyncio.start_server(
            self.handle,
            config.addr,
            config.port
        )
        await self.log(f"{config.start_msg}", (config.addr, config.port))

        async with server:
            await server.serve_forever()


async def main():
    s = WebServer()
    if not config.directory:
        print("directory not set!")
        exit(1)
    if not config.preset_file:
        print("preset file not set!")
        exit(1)
    if not os.path.isfile(config.preset_file):
        print("invalid preset file")
        exit(1)
    await s.start()


asyncio.run(main())