# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import argparse
import urllib.parse
from collections import defaultdict

import spack.fetch_strategy as fs
import spack.llnl.util.tty.color as color
import spack.repo
import spack.spec
import spack.url
import spack.util.crypto as crypto
from spack.llnl.util import tty
from spack.url import (
    UndetectableNameError,
    UndetectableVersionError,
    UrlParseError,
    color_url,
    parse_name,
    parse_name_offset,
    parse_version,
    parse_version_offset,
    substitute_version,
    substitution_offsets,
)
from spack.util.naming import simplify_name

description = "debugging tool for url parsing"
section = "developer"
level = "long"


def setup_parser(subparser: argparse.ArgumentParser) -> None:
    sp = subparser.add_subparsers(metavar="SUBCOMMAND", dest="subcommand")

    # Parse
    parse_parser = sp.add_parser("parse", help="attempt to parse a url")

    parse_parser.add_argument("url", help="url to parse")
    parse_parser.add_argument(
        "-s", "--spider", action="store_true", help="spider the source page for versions"
    )

    # List
    list_parser = sp.add_parser("list", help="list urls in all packages")

    list_parser.add_argument(
        "-c",
        "--color",
        action="store_true",
        help="color the parsed version and name in the urls shown "
        "(versions will be cyan, name red)",
    )
    list_parser.add_argument(
        "-e",
        "--extrapolation",
        action="store_true",
        help="color the versions used for extrapolation as well "
        "(additional versions will be green, names magenta)",
    )

    excl_args = list_parser.add_mutually_exclusive_group()

    excl_args.add_argument(
        "-n",
        "--incorrect-name",
        action="store_true",
        help="only list urls for which the name was incorrectly parsed",
    )
    excl_args.add_argument(
        "-N",
        "--correct-name",
        action="store_true",
        help="only list urls for which the name was correctly parsed",
    )
    excl_args.add_argument(
        "-v",
        "--incorrect-version",
        action="store_true",
        help="only list urls for which the version was incorrectly parsed",
    )
    excl_args.add_argument(
        "-V",
        "--correct-version",
        action="store_true",
        help="only list urls for which the version was correctly parsed",
    )

    # Summary
    sp.add_parser("summary", help="print a summary of how well we are parsing package urls")

    # Stats
    stats_parser = sp.add_parser(
        "stats", help="print statistics on versions and checksums for all packages"
    )
    stats_parser.add_argument(
        "--show-issues",
        action="store_true",
        help="show packages with issues (md5 hashes, http urls)",
    )


def url(parser, args):
    action = {"parse": url_parse, "list": url_list, "summary": url_summary, "stats": url_stats}

    action[args.subcommand](args)


def url_parse(args):
    url = args.url

    tty.msg("Parsing URL: {0}".format(url))
    print()

    ver, vs, vl, vi, vregex = parse_version_offset(url)
    tty.msg("Matched version regex {0:>2}: r{1!r}".format(vi, vregex))

    name, ns, nl, ni, nregex = parse_name_offset(url, ver)
    tty.msg("Matched  name   regex {0:>2}: r{1!r}".format(ni, nregex))

    print()
    tty.msg("Detected:")
    try:
        print_name_and_version(url)
    except UrlParseError as e:
        tty.error(str(e))

    print("    name:    {0}".format(name))
    print("    version: {0}".format(ver))
    print()

    tty.msg("Substituting version 9.9.9b:")
    newurl = substitute_version(url, "9.9.9b")
    print_name_and_version(newurl)

    if args.spider:
        print()
        tty.msg("Spidering for versions:")
        versions = spack.url.find_versions_of_archive(url)

        if not versions:
            print("  Found no versions for {0}".format(name))
            return

        max_len = max(len(str(v)) for v in versions)

        for v in sorted(versions):
            print("{0:{1}}  {2}".format(v, max_len, versions[v]))


def url_list(args):
    urls = set()

    # Gather set of URLs from all packages
    for pkg_cls in spack.repo.PATH.all_package_classes():
        url = getattr(pkg_cls, "url", None)
        urls = url_list_parsing(args, urls, url, pkg_cls)

        for params in pkg_cls.versions.values():
            url = params.get("url", None)
            urls = url_list_parsing(args, urls, url, pkg_cls)

    # Print URLs
    for url in sorted(urls):
        if args.color or args.extrapolation:
            print(color_url(url, subs=args.extrapolation, errors=True))
        else:
            print(url)

    # Return the number of URLs that were printed, only for testing purposes
    return len(urls)


def url_summary(args):
    # Collect statistics on how many URLs were correctly parsed
    total_urls = 0
    correct_names = 0
    correct_versions = 0

    # Collect statistics on which regexes were matched and how often
    name_regex_dict = dict()
    right_name_count = defaultdict(int)
    wrong_name_count = defaultdict(int)

    version_regex_dict = dict()
    right_version_count = defaultdict(int)
    wrong_version_count = defaultdict(int)

    tty.msg("Generating a summary of URL parsing in Spack...")

    # Loop through all packages
    for pkg_cls in spack.repo.PATH.all_package_classes():
        urls = set()
        pkg = pkg_cls(spack.spec.Spec(pkg_cls.name))

        url = getattr(pkg, "url", None)
        if url:
            urls.add(url)

        for params in pkg.versions.values():
            url = params.get("url", None)
            if url:
                urls.add(url)

        # Calculate statistics
        for url in urls:
            total_urls += 1

            # Parse versions
            version = None
            try:
                version, vs, vl, vi, vregex = parse_version_offset(url)
                version_regex_dict[vi] = vregex
                if version_parsed_correctly(pkg, version):
                    correct_versions += 1
                    right_version_count[vi] += 1
                else:
                    wrong_version_count[vi] += 1
            except UndetectableVersionError:
                pass

            # Parse names
            try:
                name, ns, nl, ni, nregex = parse_name_offset(url, version)
                name_regex_dict[ni] = nregex
                if name_parsed_correctly(pkg, name):
                    correct_names += 1
                    right_name_count[ni] += 1
                else:
                    wrong_name_count[ni] += 1
            except UndetectableNameError:
                pass

    print()
    print("    Total URLs found:          {0}".format(total_urls))
    print(
        "    Names correctly parsed:    {0:>4}/{1:>4} ({2:>6.2%})".format(
            correct_names, total_urls, correct_names / total_urls
        )
    )
    print(
        "    Versions correctly parsed: {0:>4}/{1:>4} ({2:>6.2%})".format(
            correct_versions, total_urls, correct_versions / total_urls
        )
    )
    print()

    tty.msg("Statistics on name regular expressions:")

    print()
    print("    Index   Right   Wrong   Total   Regular Expression")
    for ni in sorted(name_regex_dict.keys()):
        print(
            "    {0:>5}   {1:>5}   {2:>5}   {3:>5}   r{4!r}".format(
                ni,
                right_name_count[ni],
                wrong_name_count[ni],
                right_name_count[ni] + wrong_name_count[ni],
                name_regex_dict[ni],
            )
        )
    print()

    tty.msg("Statistics on version regular expressions:")

    print()
    print("    Index   Right   Wrong   Total   Regular Expression")
    for vi in sorted(version_regex_dict.keys()):
        print(
            "    {0:>5}   {1:>5}   {2:>5}   {3:>5}   r{4!r}".format(
                vi,
                right_version_count[vi],
                wrong_version_count[vi],
                right_version_count[vi] + wrong_version_count[vi],
                version_regex_dict[vi],
            )
        )
    print()

    # Return statistics, only for testing purposes
    return (total_urls, correct_names, correct_versions, right_name_count, right_version_count)


def url_stats(args):
    # dictionary of issue type -> package -> descriptions
    issues = defaultdict(lambda: defaultdict(lambda: []))

    class UrlStats:
        def __init__(self):
            self.total = 0
            self.schemes = defaultdict(lambda: 0)
            self.checksums = defaultdict(lambda: 0)
            self.url_type = defaultdict(lambda: 0)
            self.git_type = defaultdict(lambda: 0)

        def add(self, pkg_name, fetcher):
            self.total += 1

            url_type = fetcher.url_attr
            self.url_type[url_type or "no code"] += 1

            if url_type == "url":
                digest = getattr(fetcher, "digest", None)
                if digest:
                    algo = crypto.hash_algo_for_digest(digest)
                else:
                    algo = "no checksum"
                self.checksums[algo] += 1

                if algo == "md5":
                    md5_hashes = issues["md5 hashes"]
                    md5_hashes[pkg_name].append(fetcher.url)

                # parse out the URL scheme (https/http/ftp/etc.)
                urlinfo = urllib.parse.urlparse(fetcher.url)
                self.schemes[urlinfo.scheme] += 1

                if urlinfo.scheme == "http":
                    http_urls = issues["http urls"]
                    http_urls[pkg_name].append(fetcher.url)

            elif url_type == "git":
                if getattr(fetcher, "commit", None):
                    self.git_type["commit"] += 1
                elif getattr(fetcher, "branch", None):
                    self.git_type["branch"] += 1
                elif getattr(fetcher, "tag", None):
                    self.git_type["tag"] += 1
                else:
                    self.git_type["no ref"] += 1

    npkgs = 0
    version_stats = UrlStats()
    resource_stats = UrlStats()

    for pkg_cls in spack.repo.PATH.all_package_classes():
        npkgs += 1

        for v in list(pkg_cls.versions):
            try:
                pkg = pkg_cls(spack.spec.Spec(pkg_cls.name))
                fetcher = fs.for_package_version(pkg, v)
            except (fs.InvalidArgsError, fs.FetcherConflict):
                continue
            version_stats.add(pkg_cls.name, fetcher)

        for _, resources in pkg_cls.resources.items():
            for resource in resources:
                resource_stats.add(pkg_cls.name, resource.fetcher)

    # print a nice summary table
    tty.msg("URL stats for %d packages:" % npkgs)

    def print_line():
        print("-" * 62)

    def print_stat(indent, name, stat_name=None):
        width = 20 - indent
        fmt = " " * indent
        fmt += "%%-%ds" % width
        if stat_name is None:
            print(fmt % name)
        else:
            fmt += "%12d%8.1f%%%12d%8.1f%%"
            v = getattr(version_stats, stat_name).get(name, 0)
            r = getattr(resource_stats, stat_name).get(name, 0)
            print(
                fmt % (name, v, v / version_stats.total * 100, r, r / resource_stats.total * 100)
            )

    print_line()
    print("%-20s%12s%9s%12s%9s" % ("stat", "versions", "%", "resources", "%"))
    print_line()
    print_stat(0, "url", "url_type")

    print_stat(4, "schemes")
    schemes = set(version_stats.schemes) | set(resource_stats.schemes)
    for scheme in schemes:
        print_stat(8, scheme, "schemes")

    print_stat(4, "checksums")
    checksums = set(version_stats.checksums) | set(resource_stats.checksums)
    for checksum in checksums:
        print_stat(8, checksum, "checksums")
    print_line()

    types = set(version_stats.url_type) | set(resource_stats.url_type)
    types -= set(["url", "git"])
    for url_type in sorted(types):
        print_stat(0, url_type, "url_type")
        print_line()

    print_stat(0, "git", "url_type")
    git_types = set(version_stats.git_type) | set(resource_stats.git_type)
    for git_type in sorted(git_types):
        print_stat(4, git_type, "git_type")
    print_line()

    if args.show_issues:
        total_issues = sum(
            len(issues) for _, pkg_issues in issues.items() for _, issues in pkg_issues.items()
        )
        print()
        tty.msg("Found %d issues." % total_issues)
        for issue_type, pkgs in issues.items():
            tty.msg("Package URLs with %s" % issue_type)
            for pkg_cls, pkg_issues in pkgs.items():
                color.cprint("    @*C{%s}" % pkg_cls)
                for issue in pkg_issues:
                    print("      %s" % issue)


def print_name_and_version(url):
    """Prints a URL. Underlines the detected name with dashes and
    the detected version with tildes.

    Args:
        url (str): The url to parse
    """
    name, ns, nl, ntup, ver, vs, vl, vtup = substitution_offsets(url)
    underlines = [" "] * max(ns + nl, vs + vl)
    for i in range(ns, ns + nl):
        underlines[i] = "-"
    for i in range(vs, vs + vl):
        underlines[i] = "~"

    print("    {0}".format(url))
    print("    {0}".format("".join(underlines)))


def url_list_parsing(args, urls, url, pkg):
    """Helper function for :func:`url_list`.

    Args:
        args (argparse.Namespace): The arguments given to ``spack url list``
        urls (set): List of URLs that have already been added
        url (str or None): A URL to potentially add to ``urls`` depending on
            ``args``
        pkg (spack.package_base.PackageBase): The Spack package

    Returns:
        set: The updated set of ``urls``
    """
    if url:
        if args.correct_name or args.incorrect_name:
            # Attempt to parse the name
            try:
                name = parse_name(url)
                if args.correct_name and name_parsed_correctly(pkg, name):
                    # Add correctly parsed URLs
                    urls.add(url)
                elif args.incorrect_name and not name_parsed_correctly(pkg, name):
                    # Add incorrectly parsed URLs
                    urls.add(url)
            except UndetectableNameError:
                if args.incorrect_name:
                    # Add incorrectly parsed URLs
                    urls.add(url)
        elif args.correct_version or args.incorrect_version:
            # Attempt to parse the version
            try:
                version = parse_version(url)
                if args.correct_version and version_parsed_correctly(pkg, version):
                    # Add correctly parsed URLs
                    urls.add(url)
                elif args.incorrect_version and not version_parsed_correctly(pkg, version):
                    # Add incorrectly parsed URLs
                    urls.add(url)
            except UndetectableVersionError:
                if args.incorrect_version:
                    # Add incorrectly parsed URLs
                    urls.add(url)
        else:
            urls.add(url)

    return urls


def name_parsed_correctly(pkg, name):
    """Determine if the name of a package was correctly parsed.

    Args:
        pkg (spack.package_base.PackageBase): The Spack package
        name (str): The name that was extracted from the URL

    Returns:
        bool: True if the name was correctly parsed, else False
    """
    pkg_name = remove_prefix(pkg.name)

    name = simplify_name(name)

    return name == pkg_name


def version_parsed_correctly(pkg, version):
    """Determine if the version of a package was correctly parsed.

    Args:
        pkg (spack.package_base.PackageBase): The Spack package
        version (str): The version that was extracted from the URL

    Returns:
        bool: True if the name was correctly parsed, else False
    """
    version = remove_separators(version)

    # If the version parsed from the URL is listed in a version()
    # directive, we assume it was correctly parsed
    for pkg_version in pkg.versions:
        pkg_version = remove_separators(pkg_version)
        if pkg_version == version:
            return True
    return False


def remove_prefix(pkg_name):
    """Remove build system prefix (``'py-'``, ``'perl-'``, etc.) from a package name.

    After determining a name, ``spack create`` determines a build system.
    Some build systems prepend a special string to the front of the name.
    Since this can't be guessed from the URL, it would be unfair to say
    that these names are incorrectly parsed, so we remove them.

    Args:
        pkg_name (str): the name of the package

    Returns:
        str: the name of the package with any build system prefix removed
    """
    prefixes = [
        "r-",
        "py-",
        "tcl-",
        "lua-",
        "perl-",
        "ruby-",
        "llvm-",
        "intel-",
        "votca-",
        "octave-",
        "gtkorvo-",
    ]

    prefix = next((p for p in prefixes if pkg_name.startswith(p)), "")

    return pkg_name[len(prefix) :]


def remove_separators(version):
    """Remove separator characters (``.``, ``_``, and ``-``) from a version.

    A version like 1.2.3 may be displayed as 1_2_3 in the URL.
    Make sure 1.2.3, 1-2-3, 1_2_3, and 123 are considered equal.
    Unfortunately, this also means that 1.23 and 12.3 are equal.

    Args:
        version (str or spack.version.Version): A version

    Returns:
        str: The version with all separator characters removed
    """
    version = str(version)

    version = version.replace(".", "")
    version = version.replace("_", "")
    version = version.replace("-", "")

    return version
