import errno
import subprocess
import sys
import webbrowser
from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
from typing import Any
from zipfile import ZipFile

from briefcase.console import Console
from briefcase.exceptions import (
    BriefcaseCommandError,
    BriefcaseConfigError,
    UnsupportedCommandError,
)

if sys.version_info >= (3, 11):  # pragma: no-cover-if-lt-py311
    import tomllib
else:  # pragma: no-cover-if-gte-py311
    import tomli as tomllib

import tomli_w

from briefcase.commands import (
    BuildCommand,
    CreateCommand,
    DevCommand,
    OpenCommand,
    PackageCommand,
    PublishCommand,
    RunCommand,
    UpdateCommand,
)
from briefcase.config import AppConfig


class StaticWebMixin:
    output_format = "static"
    platform = "web"
    platform_target_version = "0.3.21"

    def project_path(self, app):
        return self.bundle_path(app) / "www"

    def binary_path(self, app):
        return self.bundle_path(app) / "www/index.html"

    def wheel_path(self, app):
        return self.project_path(app) / "static/wheels"

    def distribution_path(self, app):
        return self.dist_path / f"{app.formal_name}-{app.version}.web.zip"


class StaticWebCreateCommand(StaticWebMixin, CreateCommand):
    description = "Create and populate a static web project."

    def output_format_template_context(self, app: AppConfig):
        """Add style framework details to the app template."""
        return {
            "style_framework": getattr(app, "style_framework", "None"),
        }


class StaticWebUpdateCommand(StaticWebCreateCommand, UpdateCommand):
    description = "Update an existing static web project."


class StaticWebOpenCommand(StaticWebMixin, OpenCommand):
    description = "Open the folder containing an existing static web project."


class StaticWebBuildCommand(StaticWebMixin, BuildCommand):
    description = "Build a static web project."

    def _trim_file(self, path, sentinel):
        """Re-write a file to strip any content after a sentinel line.

        The file is stored in-memory, so it shouldn't be used on files with a *lot* of
        content before the sentinel.

        :param path: The path to the file to be trimmed
        :param sentinel: The content of the sentinel line. This will become the last
            line in the trimmed file.
        """
        content = []
        with path.open("r", encoding="utf-8") as f:
            for line in f:
                if line.rstrip("\n") == sentinel:
                    content.append(line)
                    break
                else:
                    content.append(line)

        with path.open("w", encoding="utf-8") as f:
            for line in content:
                f.write(line)

    def _process_wheel(self, wheelfile, css_file):
        """Process a wheel, extracting any content that needs to be compiled into the
        final project.

        :param wheelfile: The path to the wheel file to be processed.
        :param css_file: A file handle, opened for write/append, to which any extracted
            CSS content will be appended.
        """
        package = " ".join(wheelfile.name.split("-")[:2])
        with ZipFile(wheelfile) as wheel:
            for filename in wheel.namelist():
                path = Path(filename)
                # Any CSS file in a `static` folder is appended
                if (
                    len(path.parts) > 1
                    and path.parts[1] == "static"
                    and path.suffix == ".css"
                ):
                    self.console.info(f"    Found {filename}")
                    css_file.write(
                        "\n/*******************************************************\n"
                    )
                    css_file.write(f" * {package}::{'/'.join(path.parts[2:])}\n")
                    css_file.write(
                        " *******************************************************/\n\n"
                    )
                    css_file.write(wheel.read(filename).decode("utf-8"))

    def build_app(self, app: AppConfig, **kwargs):
        """Build the static web deployment for the application.

        :param app: The application to build
        """
        self.console.info("Building web project...", prefix=app.app_name)

        if self.wheel_path(app).exists():
            with self.console.wait_bar("Removing old wheels..."):
                self.tools.shutil.rmtree(self.wheel_path(app))

        self.wheel_path(app).mkdir(parents=True)

        with self.console.wait_bar("Building app wheel..."):
            try:
                self.tools.subprocess.run(
                    [
                        sys.executable,
                        "-u",
                        "-X",
                        "utf8",
                        "-m",
                        "wheel",
                        "pack",
                        self.app_path(app),
                        "--dest-dir",
                        self.wheel_path(app),
                    ],
                    check=True,
                    encoding="UTF-8",
                )
            except subprocess.CalledProcessError as e:
                raise BriefcaseCommandError(
                    f"Unable to build wheel for app {app.app_name!r}"
                ) from e

        with self.console.wait_bar("Installing wheels for requirements..."):
            try:
                self.tools.subprocess.run(
                    [
                        sys.executable,
                        "-u",
                        "-X",
                        "utf8",
                        "-m",
                        "pip",
                        "wheel",
                        "--wheel-dir",
                        self.wheel_path(app),
                        "-r",
                        self.bundle_path(app) / "requirements.txt",
                    ]
                    + (["-vv"] if self.console.is_deep_debug else []),
                    check=True,
                    encoding="UTF-8",
                )
            except subprocess.CalledProcessError as e:
                raise BriefcaseCommandError(
                    f"Unable to install requirements for app {app.app_name!r}"
                ) from e

        with self.console.wait_bar("Writing Pyscript configuration file..."):
            # Load any pre-existing pyscript.toml provided by the template. If the file
            # doesn't exist, assume an empty pyscript.toml as a starting point.
            try:
                with (self.project_path(app) / "pyscript.toml").open("rb") as f:
                    config = tomllib.load(f)
            except tomllib.TOMLDecodeError as e:
                raise BriefcaseConfigError(
                    f"pyscript.toml content isn't valid TOML: {e}"
                ) from e
            except FileNotFoundError:
                config = {}

            # Add the packages declaration to the existing pyscript.toml.
            # Ensure that we're using Unix path separators, as the content
            # will be parsed by pyscript in the browser.
            config["packages"] = [
                f"/{'/'.join(wheel.relative_to(self.project_path(app)).parts)}"
                for wheel in sorted(self.wheel_path(app).glob("*.whl"))
            ]

            # Parse any additional pyscript.toml content, and merge it into
            # the overall content
            try:
                extra = tomllib.loads(app.extra_pyscript_toml_content)
                config.update(extra)
            except tomllib.TOMLDecodeError as e:
                raise BriefcaseConfigError(
                    f"Extra pyscript.toml content isn't valid TOML: {e}"
                ) from e
            except AttributeError:
                pass

            # Write the final configuration.
            with (self.project_path(app) / "pyscript.toml").open("wb") as f:
                tomli_w.dump(config, f)

        self.console.info("Compile static web content from wheels")
        with self.console.wait_bar("Compiling static web content from wheels..."):
            # Trim previously compiled content out of briefcase.css
            briefcase_css_path = self.project_path(app) / "static/css/briefcase.css"
            self._trim_file(
                briefcase_css_path,
                sentinel=" ******************* Wheel contributed styles **********************/",
            )

            # Extract static resources from packaged wheels
            for wheelfile in sorted(self.wheel_path(app).glob("*.whl")):
                self.console.info(f"  Processing {wheelfile.name}...")
                with briefcase_css_path.open("a", encoding="utf-8") as css_file:
                    self._process_wheel(wheelfile, css_file=css_file)

        return {}


class HTTPHandler(SimpleHTTPRequestHandler):
    """Convert any HTTP request into a path request on the static content folder."""

    server: "LocalHTTPServer"

    def translate_path(self, path):
        return str(self.server.base_path / path[1:])

    def end_headers(self):
        self.send_header("Cache-Control", "no-cache, no-store, must-revalidate")
        self.send_header("Pragma", "no-cache")
        self.send_header("Expires", "0")
        super().end_headers()

    # Strip out ANSI escape sequences from messages. This was added in security releases
    # before Python 3.12.
    _control_char_table = str.maketrans(
        {c: rf"\x{c:02x}" for c in [*range(0x20), *range(0x7F, 0xA0)]}
    )
    _control_char_table[ord("\\")] = r"\\"

    def log_message(self, format: str, *args: Any) -> None:
        message = (format % args).translate(self._control_char_table)
        self.server.logger.info(
            f"{self.address_string()} - - [{self.log_date_time_string()}] {message}"
        )


class LocalHTTPServer(ThreadingHTTPServer):
    """An HTTP server that serves local static content."""

    def __init__(
        self,
        base_path,
        host,
        port,
        RequestHandlerClass=HTTPHandler,
        *,
        logger: Console,
    ):
        self.base_path = base_path
        self.logger = logger
        super().__init__((host, port), RequestHandlerClass)


class StaticWebRunCommand(StaticWebMixin, RunCommand):
    description = "Run a static web project."

    def add_options(self, parser):
        super().add_options(parser)
        parser.add_argument(
            "--host",
            default="localhost",
            help="The host on which to run the server (default: localhost)",
            required=False,
        )
        parser.add_argument(
            "-p",
            "--port",
            default=8080,
            type=int,
            help="The port on which to run the server (default: 8080)",
            required=False,
        )
        parser.add_argument(
            "--no-browser",
            action="store_false",
            dest="open_browser",
            help="Don't open a web browser on the newly opened server",
            required=False,
        )

    def run_app(
        self,
        app: AppConfig,
        passthrough: list[str],
        host,
        port,
        open_browser,
        **kwargs,
    ):
        """Start the application.

        :param app: The config object for the app
        :param passthrough: The list of arguments to pass to the app
        :param host: The host on which to run the server
        :param port: The port on which to run the server
        :param open_browser: Should a browser be opened on the newly started server.
        """
        if app.test_mode:
            raise BriefcaseCommandError("Briefcase can't run web apps in test mode.")

        self.console.info("Starting web server...", prefix=app.app_name)

        # At least for now, there's no easy way to pass arguments to a web app.
        if passthrough:
            self.console.warning(f"Ignoring passthrough arguments: {passthrough}")

        httpd = None
        try:
            # Create a local HTTP server
            try:
                httpd = LocalHTTPServer(
                    self.project_path(app),
                    host=host,
                    port=port,
                    logger=self.console,
                )
            except OSError as e:
                if e.errno in (errno.EADDRINUSE, errno.ENOSR):
                    self.console.warning(
                        f"Using a system-allocated port since port {port} is already in use. "
                        "Use -p/--port to manually specify a port."
                    )
                    httpd = LocalHTTPServer(
                        self.project_path(app),
                        host=host,
                        port=0,
                        logger=self.console,
                    )
                else:
                    raise

            # Extract the host and port from the server. This is needed
            # because specifying a port of 0 lets the server pick a port.
            host, port = httpd.socket.getsockname()
            url = f"http://{host}:{port}"

            self.console.info(f"Web server open on {url}")
            # If requested, open a browser tab on the newly opened server.
            if open_browser:
                webbrowser.open_new_tab(url)

            self.console.info(
                "Web server log output (type CTRL-C to stop log)...",
                prefix=app.app_name,
            )
            self.console.info("=" * 75)

            # Run the server.
            httpd.serve_forever()
        except PermissionError as e:
            if port < 1024:
                raise BriefcaseCommandError(
                    "Unable to start web server; Permission denied. Try using a port > 1023."
                ) from e
            else:
                raise BriefcaseCommandError(
                    "Unable to start web server; Permission denied. Did you specify a valid host and port?"
                ) from e
        except OSError as e:
            if e.errno in (errno.EADDRNOTAVAIL, errno.ENOSTR):
                raise BriefcaseCommandError(
                    f"Unable to start web server. {host} is not a valid hostname."
                ) from e
            else:
                raise BriefcaseCommandError(f"Unable to start web server. {e}") from e
        except OverflowError as e:
            raise BriefcaseCommandError(
                "Unable to start web server. Port must be in the range 0-65535."
            ) from e
        except KeyboardInterrupt:
            # CTRL-C is the accepted way to stop the server.
            httpd.shutdown()
        finally:
            if httpd:
                with self.console.wait_bar("Shutting down server..."):
                    httpd.server_close()

            # Not sure why, but this is needed to mollify coverage for the
            # "test_cleanup_server_error" case. Without this pass, a missing branch
            # is reported for the "if httpd: -> exit" branch
            pass

        return {}


class StaticWebPackageCommand(StaticWebMixin, PackageCommand):
    description = "Package a static web app."

    @property
    def packaging_formats(self):
        return ["zip"]

    @property
    def default_packaging_format(self):
        return "zip"

    def package_app(self, app: AppConfig, **kwargs):
        """Package an app for distribution.

        :param app: The app to package.
        """
        self.console.info(
            "Packaging web app for distribution...",
            prefix=app.app_name,
        )

        with self.console.wait_bar("Building archive..."):
            self.tools.shutil.make_archive(
                self.distribution_path(app).with_suffix(""),
                format="zip",
                root_dir=self.project_path(app),
            )


class StaticWebPublishCommand(StaticWebMixin, PublishCommand):
    description = "Publish a static web app."
    publication_channels = ["s3"]
    default_publication_channel = "s3"


class StaticWebDevCommand(StaticWebMixin, DevCommand):
    description = "Run a static web project in development mode. (Work in progress)"

    def run_dev_app(self, app: AppConfig, env, passthrough=None, **kwargs):
        raise UnsupportedCommandError(
            platform="web",
            output_format="static",
            command="dev",
        )

    # implement logic to run the web server in development mode


# Declare the briefcase command bindings
create = StaticWebCreateCommand
update = StaticWebUpdateCommand
open = StaticWebOpenCommand
build = StaticWebBuildCommand
run = StaticWebRunCommand
package = StaticWebPackageCommand
publish = StaticWebPublishCommand
dev = StaticWebDevCommand