# SPDX-License-Identifier: BSD-2-Clause
# SPDX-FileCopyrightText: 2023 KDE e.V.
# SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>

import logging
from pathlib import Path
from typing import Any, Dict, IO, List, Optional, Union

import yaml

log = logging.getLogger(__name__)


class Error(Exception):
    pass


def readProjectSettings(yamlStream: Union[str, IO]) -> None:
    global settings
    settings = ProjectSettings(yamlStream)


class ProjectSettings:
    # Possible boolean values (same as configparser)
    BOOLEAN_STATES = {
        "1": True,
        "yes": True,
        "true": True,
        "on": True,
        "0": False,
        "no": False,
        "false": False,
        "off": False,
    }

    def __init__(self, yamlStream: Union[str, IO]):
        self._projects: Dict[str, Dict[str, Dict[str, str]]] = {}
        self._readSettings(yamlStream)

    def _readSettings(self, yamlStream):
        try:
            # Set "nosec B506" to silence false positive warning "Use of unsafe yaml load.
            # Allows instantiation of arbitrary objects. Consider yaml.safe_load()."
            # We use yaml.load with BaseLoader which is even safer than SafeLoader.
            d = yaml.load(yamlStream, yaml.BaseLoader)  # nosec B506
        except Exception as e:
            log.error("Error: Failed to read project settings.")
            log.debug("Error details:", exc_info=e)
            return
        if d is None:
            # PyYAML didn't find any documents in the stream
            return

        defaultSettings = d.get("defaults", {})
        defaultBranches = []
        if "branches" in defaultSettings:
            defaultBranches = defaultSettings["branches"]
            del defaultSettings["branches"]

        projects = {}
        for p in d:
            if p == "defaults":
                continue
            projects[p] = _readProject(d[p] or {}, defaultBranches, defaultSettings)

        self._projects = projects

    def exists(self, projectPath: str, branch: Optional[str] = None) -> bool:
        if branch is None:
            return projectPath in self._projects
        return branch in self._projects.get(projectPath, {})

    def get(self, projectPath: str, branch: str, key: str, default: Any = None) -> Any:
        p = self._projects.get(projectPath)
        if p is None:
            raise Error(f"Unknown project '{projectPath}'")
        b = p.get(branch)
        if b is None:
            raise Error(f"Unknown branch '{branch}' of project '{projectPath}'")
        return b.get(key, default)

    def getBool(self, projectPath: str, branch: str, key: str, default: bool) -> bool:
        value = self.get(projectPath, branch, key, default)
        if isinstance(value, str):
            if value.lower() not in self.BOOLEAN_STATES:
                raise ValueError("Not a boolean: %s" % value)
            value = self.BOOLEAN_STATES[value.lower()]
        return value

    def getPath(
        self, projectPath: str, branch: str, key: str, default: Optional[Union[Path, str]] = None
    ) -> Optional[Path]:
        v = self.get(projectPath, branch, key, default)
        if isinstance(v, str):
            v = Path(v).expanduser()
        return v


def _readProject(projectSettings: dict, defaultBranches: List[str], defaultSettings: dict):
    project = {}
    branches = projectSettings.get("branches")
    if branches is not None:
        del projectSettings["branches"]

        for b in branches:
            # initialize with the default settings
            branchSettings = defaultSettings.copy()
            # update with the project settings
            branchSettings.update(projectSettings.copy())
            # update with the branch-specific settings
            branchSettings.update(branches[b] or {})
            project[b] = branchSettings

    # add the default branches
    for b in defaultBranches:
        if b not in project:
            branchSettings = defaultSettings.copy()
            branchSettings.update(projectSettings.copy())
            project[b] = branchSettings

    return project


settings = ProjectSettings("")