# Copyright 2021-2024 Avaiga Private Limited
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
# an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the License.
# --------------------------------------------------------------------------------------------------
# Common artifacts used by the other scripts located in this directory.
# --------------------------------------------------------------------------------------------------
import os
import re
import subprocess
import typing as t
from dataclasses import asdict, dataclass

import requests

# These are the base name of the sub packages taipy-*
# They also are the names of the directory where their code belongs, under the 'taipy' directory
# in the root of the Taipy repository.
PACKAGES = ["common", "core", "gui", "rest", "templates"]


# --------------------------------------------------------------------------------------------------
@dataclass(order=True)
class Version:
    """Helps manipulate version numbers."""

    major: int
    minor: int
    patch: int = 0
    ext: t.Optional[str] = None

    # Unknown version constant
    UNKNOWN: t.ClassVar["Version"]

    @property
    def name(self) -> str:
        """Returns a string representation of this Version without the extension part."""
        return f"{self.major}.{self.minor}.{self.patch}"

    @property
    def full_name(self) -> str:
        """Returns a full string representation of this Version."""
        return f"{self.name}.{self.ext}" if self.ext else self.name

    def __str__(self) -> str:
        """Returns a string representation of this version."""
        return self.full_name

    def __repr__(self) -> str:
        """Returns a full string representation of this version."""
        ext = f".{self.ext}" if self.ext else ""
        return f"Version({self.major}.{self.minor}.{self.patch}{ext})"

    @classmethod
    def from_string(cls, version: str):
        """Creates a Version from a string.

        Parameters:
            version: a version name as a string.<br/>
              The format should be "<major>.<minor>[.<patch>[.<extension>]] where

              - <major> must be a number, indicating the major number of the version
              - <minor> must be a number, indicating the minor number of the version
              - <patch> must be a number, indicating the patch level of the version. Optional.
              - <extension> must be a string. It is common practice that <extension> ends with a
                number, but it is not required. Optional.
        Returns:
            A new Version object with the appropriate values that were parsed.
        """
        match = re.fullmatch(r"(\d+)\.(\d+)(?:\.(\d+))?(?:\.([^\s]+))?", version)
        if match:
            major = int(match[1])
            minor = int(match[2])
            patch = int(match[3]) if match[3] else 0
            ext = match[4]
            return cls(major=major, minor=minor, patch=patch, ext=ext)
        else:
            raise ValueError(f"String not in expected format: {version}")

    def to_dict(self) -> dict[str, str]:
        """Returns this Version as a dictionary."""
        return {k: v for k, v in asdict(self).items() if v is not None}

    def bump_ext_version(self) -> "Version":
        """Returns a new Version object where the extension part version was incremented.

        If this Version has no extension part, this method returns *self*.
        """
        if not self.ext or (m := re.search(r"([0-9]+)$", self.ext)) is None:
            return self

        ext_ver = int(m[1]) + 1
        return Version(self.major, self.minor, self.patch, f"{self.ext[: m.start(1)]}{ext_ver}")

    def validate_extension(self, ext="dev"):
        """Returns True if the extension part of this Version is the one queried."""
        return self._split_ext()[0] == ext

    def _split_ext(self) -> t.Tuple[str, int]:
        """Splits extension into the (identifier, index) tuple

        Returns:
            ("", -1) if there is no extension.
            (extension, -1) if there is no extension index.
            (extension, index) if there is an extension index (e.g. "dev3").
        """
        if not self.ext or (match := re.fullmatch(r"(.*?)(\d+)?", self.ext)) is None:
            return ("", -1)  # No extension
        # Potentially no index
        return (match[1], int(match[2]) if match[2] else -1)

    def is_compatible(self, version: "Version") -> bool:
        """Checks if this version is compatible with another.

        Version v1 is defined as being compatible with version v2 if a package built with version v1
        can safely depend on another package built with version v2.<br/>
        Here are the conditions set when checking whether v1 is compatible with v2:

        - If v1 and v2 have different major or minor numbers, they are not compatible.
        - If v1 has no extension, it is compatible only with v2 that have no extension.
        - If v1 has an extension, it is compatible with any v2 that has the same extension, no
          matter the extension index.

        I.e.:
            package-1.[m].[t] is NOT compatible with any sub-package-[M].* where M != 1
            package-1.2.[t] is NOT compatible with any sub-package-1.[m].* where m != 2
            package-1.2.[t] is compatible with all sub-package-1.2.*
            package-1.2.[t].ext[X] is compatible with all sub-package-1.2.*.ext*
            package-1.2.3 is NOT compatible with any sub-package-1.2.*.*
            package-1.2.3.extA is NOT compatible with any sub-package-1.2.*.extB if extA != extB,
               independently of a potential extension index.

        Parameters:
            version: the version to check compatibility against.

        Returns:
            True is this Version is compatible with *version* and False if it is not.
        """
        if self.major != version.major or self.minor != version.minor:
            return False
        if self.patch > version.patch:
            return True

        # No extensions on either → Compatible
        if not self.ext and not version.ext:
            return True

        # self has extension, version doesn't → Compatible
        if self.ext and not version.ext:
            return True

        # Version has extension, self doesn't → Not compatible
        if not self.ext and version.ext:
            return False

        # Both have extensions → check identifiers. Dissimilar identifiers → Not compatible
        self_prefix, _ = self._split_ext()
        other_prefix, _ = version._split_ext()
        if self_prefix != other_prefix:
            return False

        # Same identifiers → Compatible
        return True


Version.UNKNOWN = Version(0, 0)


# --------------------------------------------------------------------------------------------------
class Package:
    """Information on any Taipy package and sub-package."""

    def __init__(self, package: str) -> None:
        self._name = package
        if package == "taipy":
            self._short = package
        else:
            if package.startswith("taipy-"):
                self._short = package[6:]
            else:
                self._name = f"taipy-{package}"
                self._short = package
            if self._short not in PACKAGES:
                raise ValueError(f"Invalid package name {package}.")

    @property
    def name(self) -> str:
        """The full package name."""
        return self._name

    @property
    def short_name(self) -> str:
        """The short package name."""
        return self._short

    @property
    def package_dir(self) -> str:
        return "taipy" if self._name == "taipy" else os.path.join("taipy", self._short)

    def __str__(self) -> str:
        """Returns a string representation of this package."""
        return self.name

    def __repr__(self) -> str:
        """Returns a full string representation of this package."""
        return f"Package({self.name})"

    def __eq__(self, other):
        return isinstance(other, Package) and (self._short, self._short) == (other._short, other._short)

    def __hash__(self):
        return hash(self._short)


# --------------------------------------------------------------------------------------------------
def retrieve_github_path() -> t.Optional[str]:
    # Retrieve current Git branch remote URL
    def run(*args) -> str:
        return subprocess.run(args, stdout=subprocess.PIPE, text=True, check=True).stdout.strip()

    branch_name = run("git", "branch", "--show-current")
    remote_name = run("git", "config", f"branch.{branch_name}.remote")
    url = run("git", "remote", "get-url", remote_name)
    if match := re.fullmatch(r"git@github.com:(.*)\.git", url):
        return match[1]
    if match := re.fullmatch(r"https://github.com/(.*)$", url):
        return match[1]
    print("ERROR - Could not retrieve GibHub branch path")  # noqa: T201
    return None


# --------------------------------------------------------------------------------------------------
def fetch_github_releases(gh_path: t.Optional[str] = None) -> dict[Package, list[Version]]:
    # Retrieve all available releases (potentially paginating results) for all packages.
    # Returns a dictionary of package_short_name-Value pairs.
    # Note for reviewers: using a Package as the dictionary is is cumbersome in the rest of the
    # code.
    all_releases: dict[str, list[Version]] = {}
    if gh_path is None:
        gh_path = retrieve_github_path()
        if gh_path is None:
            raise ValueError("Couldn't figure out GitHub branch path.")
    url = f"https://api.github.com/repos/{gh_path}/releases"
    page = 1
    # Read all release versions and store them in a package_name - list[Version] dictionary
    while url:
        response = requests.get(url, params={"per_page": 50, "page": page})
        response.raise_for_status()  # Raise error for bad responses
        for release in response.json():
            tag_name = release["tag_name"]
            pkg_ver, pkg = tag_name.split("-") if "-" in tag_name else (tag_name, "taipy")
            # Drop legacy packages (config...)
            if pkg != "taipy" and pkg not in PACKAGES:
                continue

            # Exception for legacy version: v1.0.0 -> 1.0.0
            if pkg_ver == "v1.0.0":
                pkg_ver = pkg_ver[1:]
            version = Version.from_string(pkg_ver)
            if versions := all_releases.get(pkg):
                versions.append(version)
            else:
                all_releases[pkg] = [version]

        # Check for pagination in the `Link` header
        link_header = response.headers.get("Link", "")
        if 'rel="next"' in link_header:
            url = link_header.split(";")[0].strip("<>")  # Extract next page URL
            page += 1
        else:
            url = None  # No more pages

    # Build and return the dictionary using Package instances
    return {Package(p): v for p, v in all_releases.items()}


# --------------------------------------------------------------------------------------------------
def fetch_latest_github_taipy_releases(
    all_releases: t.Optional[dict[Package, list[Version]]] = None, gh_path: t.Optional[str] = None
) -> Version:
    # Retrieve all available releases if necessary
    if all_releases is None:
        all_releases = fetch_github_releases(gh_path)
    # Find the latest 'taipy' version that has no extension
    latest_taipy_version = Version.UNKNOWN
    if versions := all_releases.get(Package("taipy")):
        latest_taipy_version = max(filter(lambda v: v.ext is None, versions))
    return latest_taipy_version