#!/usr/bin/env python
#
# Copyright (C) 2019-2021 Hiroshi Miura <miurahr@linux.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
# the Software, and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
# COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
# IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import configparser
import hashlib
import json
import logging.config
import os
import sys
import xml.etree.ElementTree as ElementTree
from logging import getLogger
from logging.handlers import QueueListener
from pathlib import Path
from typing import Callable, Dict, List, Tuple
from urllib.parse import urlparse

import requests
import requests.adapters

from aqt.exceptions import ArchiveChecksumError, ArchiveConnectionError, ArchiveDownloadError, ArchiveListError


def _get_meta(url: str):
    return requests.get(url + ".meta4")


def _check_content_type(ct: str) -> bool:
    candidate = ["application/metalink4+xml", "text/plain"]
    return any(ct.startswith(t) for t in candidate)


def getUrl(url: str, timeout) -> str:
    logger = getLogger("aqt.helper")
    with requests.sessions.Session() as session:
        retries = requests.adapters.Retry(
            total=Settings.max_retries_on_connection_error, backoff_factor=Settings.backoff_factor
        )
        adapter = requests.adapters.HTTPAdapter(max_retries=retries)
        session.mount("http://", adapter)
        session.mount("https://", adapter)
        try:
            r = session.get(url, allow_redirects=False, timeout=timeout)
            num_redirects = 0
            while 300 < r.status_code < 309 and num_redirects < 10:
                num_redirects += 1
                logger.debug("Asked to redirect({}) to: {}".format(r.status_code, r.headers["Location"]))
                newurl = altlink(r.url, r.headers["Location"])
                logger.info("Redirected: {}".format(urlparse(newurl).hostname))
                r = session.get(newurl, stream=True, timeout=timeout)
        except (
            ConnectionResetError,
            requests.exceptions.ConnectionError,
            requests.exceptions.Timeout,
        ) as e:
            raise ArchiveConnectionError(f"Failure to connect to {url}: {type(e).__name__}") from e
        else:
            if r.status_code != 200:
                msg = f"Failed to retrieve file at {url}\nServer response code: {r.status_code}, reason: {r.reason}"
                raise ArchiveDownloadError(msg)
        result = r.text
    return result


def downloadBinaryFile(url: str, out: Path, hash_algo: str, exp: bytes, timeout):
    logger = getLogger("aqt.helper")
    filename = Path(url).name
    with requests.sessions.Session() as session:
        retries = requests.adapters.Retry(
            total=Settings.max_retries_on_connection_error, backoff_factor=Settings.backoff_factor
        )
        adapter = requests.adapters.HTTPAdapter(max_retries=retries)
        session.mount("http://", adapter)
        session.mount("https://", adapter)
        try:
            r = session.get(url, allow_redirects=False, stream=True, timeout=timeout)
            if 300 < r.status_code < 309:
                logger.debug("Asked to redirect({}) to: {}".format(r.status_code, r.headers["Location"]))
                newurl = altlink(r.url, r.headers["Location"])
                logger.info("Redirected: {}".format(urlparse(newurl).hostname))
                r = session.get(newurl, stream=True, timeout=timeout)
        except requests.exceptions.ConnectionError as e:
            raise ArchiveConnectionError(f"Connection error: {e.args}") from e
        except requests.exceptions.Timeout as e:
            raise ArchiveConnectionError(f"Connection timeout: {e.args}") from e
        else:
            hash = hashlib.new(hash_algo)
            try:
                with open(out, "wb") as fd:
                    for chunk in r.iter_content(chunk_size=8196):
                        fd.write(chunk)
                        hash.update(chunk)
                    fd.flush()
            except Exception as e:
                raise ArchiveDownloadError(f"Download of {filename} has error: {e}") from e
            if exp is not None and hash.digest() != exp:
                raise ArchiveChecksumError(
                    f"Downloaded file {filename} is corrupted! Detect checksum error.\n"
                    f"Expect {exp.hex()}: {url}\n"
                    f"Actual {hash.digest().hex()}: {out.name}"
                )


def retry_on_errors(action: Callable[[], any], acceptable_errors: Tuple, num_retries: int, name: str):
    logger = getLogger("aqt.helper")
    for i in range(num_retries):
        try:
            retry_msg = f": attempt #{1 + i}" if i > 0 else ""
            logger.info(f"{name}{retry_msg}...")
            ret = action()
            if i > 0:
                logger.info(f"Success on attempt #{1 + i}: {name}")
            return ret
        except acceptable_errors as e:
            if i < num_retries - 1:
                continue  # just try again
            raise e from e


def altlink(url: str, alt: str):
    """
    Blacklisting redirected(alt) location based on Settings.blacklist configuration.
    When found black url, then try download a url + .meta4 that is a metalink version4
    xml file, parse it and retrieve best alternative url.
    """
    logger = getLogger("aqt.helper")
    if not any(alt.startswith(b) for b in Settings.blacklist):
        return alt
    try:
        m = _get_meta(url)
    except requests.exceptions.ConnectionError:
        logger.error("Got connection error. Fall back to recovery plan...")
        return alt
    else:
        # Expected response->'application/metalink4+xml; charset=utf-8'
        if not _check_content_type(m.headers["content-type"]):
            logger.error("Unexpected meta4 response;content-type: {}".format(m.headers["content-type"]))
            return alt
        try:
            mirror_xml = ElementTree.fromstring(m.text)
            meta_urls = {}
            for f in mirror_xml.iter("{urn:ietf:params:xml:ns:metalink}file"):
                for u in f.iter("{urn:ietf:params:xml:ns:metalink}url"):
                    meta_urls[u.attrib["priority"]] = u.text
            mirrors = [meta_urls[i] for i in sorted(meta_urls.keys(), key=lambda x: int(x))]
        except Exception:
            exc_info = sys.exc_info()
            logger.error("Unexpected meta4 file; parse error: {}".format(exc_info[1]))
            return alt
        else:
            # Return first priority item which is not blacklist in mirrors list,
            # if not found then return alt in default
            return next(
                filter(
                    lambda mirror: not any(mirror.startswith(b) for b in Settings.blacklist),
                    mirrors,
                ),
                alt,
            )


class MyQueueListener(QueueListener):
    def __init__(self, queue):
        handlers = []
        super().__init__(queue, *handlers)

    def handle(self, record):
        """
        Handle a record from subprocess.
        Override logger name then handle at proper logger.
        """
        record = self.prepare(record)
        logger = getLogger("aqt.installer")
        record.name = "aqt.installer"
        logger.handle(record)


def xml_to_modules(
    xml_text: str,
    predicate: Callable[[ElementTree.Element], bool],
) -> Dict[str, Dict[str, str]]:
    """Converts an XML document to a dict of `PackageUpdate` dicts, indexed by `Name` attribute.
    Only report elements that satisfy `predicate(element)`.
    Reports all keys available in the PackageUpdate tag as strings.

    :param xml_text: The entire contents of an xml file
    :param predicate: A function that decides which elements to keep or discard
    """
    try:
        parsed_xml = ElementTree.fromstring(xml_text)
    except ElementTree.ParseError as perror:
        raise ArchiveListError(f"Downloaded metadata is corrupted. {perror}") from perror
    packages = {}
    for packageupdate in parsed_xml.iter("PackageUpdate"):
        if predicate and not predicate(packageupdate):
            continue
        name = packageupdate.find("Name").text
        packages[name] = {}
        for child in packageupdate:
            packages[name][child.tag] = child.text
    return packages


class MyConfigParser(configparser.ConfigParser):
    def getlist(self, section: str, option: str, fallback=[]) -> List[str]:
        value = self.get(section, option)
        try:
            result = list(filter(None, (x.strip() for x in value.splitlines())))
        except Exception:
            result = fallback
        return result

    def getlistint(self, section: str, option: str, fallback=[]):
        try:
            result = [int(x) for x in self.getlist(section, option)]
        except Exception:
            result = fallback
        return result


class SettingsClass:
    """
    Class to hold configuration and settings.
    Actual values are stored in 'settings.ini' file.
    It also holds a combinations database.
    """

    def __init__(self):
        self.config = MyConfigParser()
        self.configfile = os.path.join(os.path.dirname(__file__), "settings.ini")
        self.loggingconf = os.path.join(os.path.dirname(__file__), "logging.ini")

    def load_settings(self, file=None):
        with open(
            os.path.join(os.path.dirname(__file__), "combinations.json"),
            "r",
        ) as j:
            self._combinations = json.load(j)[0]
        if file is not None:
            if isinstance(file, str):
                result = self.config.read(file)
                if len(result) == 0:
                    raise IOError("Fails to load specified config file {}".format(file))
                self.configfile = file
            else:
                # passed through command line argparse.FileType("r")
                self.config.read_file(file)
                self.configfile = file
                file.close()
        else:
            if isinstance(self.configfile, str):
                with open(self.configfile, "r") as f:
                    self.config.read_file(f)
            else:
                self.configfile.seek(0)
                self.config.read_file(self.configfile)

    @property
    def qt_combinations(self):
        return self._combinations["qt"]

    @property
    def tools_combinations(self):
        return self._combinations["tools"]

    @property
    def available_versions(self):
        return self._combinations["versions"]

    @property
    def available_offline_installer_version(self):
        res = self._combinations["new_archive"]
        res.extend(self._combinations["versions"])
        return res

    def available_modules(self, qt_version):
        """Known module names

        :returns: dictionary of qt_version and module names
        :rtype: List[str]
        """
        modules = self._combinations["modules"]
        versions = qt_version.split(".")
        version = "{}.{}".format(versions[0], versions[1])
        result = None
        for record in modules:
            if record["qt_version"] == version:
                result = record["modules"]
        return result

    @property
    def archive_download_location(self):
        return self.config.get("aqt", "archive_download_location", fallback=".")

    @property
    def always_keep_archives(self):
        return self.config.getboolean("aqt", "always_keep_archives", fallback=False)

    @property
    def concurrency(self):
        """concurrency configuration.

        :return: concurrency
        :rtype: int
        """
        return self.config.getint("aqt", "concurrency", fallback=4)

    @property
    def blacklist(self):
        """list of sites in a blacklist

        :returns: list of site URLs(scheme and host part)
        :rtype: List[str]
        """
        return self.config.getlist("mirrors", "blacklist", fallback=[])

    @property
    def baseurl(self):
        return self.config.get("aqt", "baseurl", fallback="https://download.qt.io")

    @property
    def connection_timeout(self):
        return self.config.getfloat("requests", "connection_timeout", fallback=3.5)

    @property
    def response_timeout(self):
        return self.config.getfloat("requests", "response_timeout", fallback=10)

    @property
    def max_retries(self):
        """Deprecated: please use `max_retries_on_connection_error` and `max_retries_on_checksum_error` instead!"""
        return self.config.getfloat("requests", "max_retries", fallback=5)

    @property
    def max_retries_on_connection_error(self):
        return self.config.getfloat("requests", "max_retries_on_connection_error", fallback=self.max_retries)

    @property
    def max_retries_on_checksum_error(self):
        return self.config.getint("requests", "max_retries_on_checksum_error", fallback=int(self.max_retries))

    @property
    def backoff_factor(self):
        return self.config.getfloat("requests", "retry_backoff", fallback=0.1)

    @property
    def fallbacks(self):
        return self.config.getlist("mirrors", "fallbacks", fallback=[])

    @property
    def zipcmd(self):
        return self.config.get("aqt", "7zcmd", fallback="7z")

    @property
    def kde_patches(self):
        return self.config.getlist("kde_patches", "patches", fallback=[])

    @property
    def print_stacktrace_on_error(self):
        return self.config.getboolean("aqt", "print_stacktrace_on_error", fallback=False)

    @property
    def min_module_size(self):
        """
        Some modules in the Qt repository contain only empty directories.
        We have found that these modules are no more than 40 bytes after decompression.
        This setting is used to filter out these empty modules in `list-*` output.
        """
        return self.config.getint("aqt", "min_module_size", fallback=41)


Settings = SettingsClass()


def setup_logging(env_key="LOG_CFG"):
    config = os.getenv(env_key, None)
    if config is not None and os.path.exists(config):
        logging.config.fileConfig(config)
    else:
        logging.config.fileConfig(Settings.loggingconf)