import aiohttp

from ..logger import logger
from ..models import Issue, Repository


def _populate_headers(repository: Repository) -> dict[str, str]:
    headers: dict[str, str] = {"User-Agent": repository.user_agent}
    if repository.provider.token is not None:
        headers["Authorization"] = f"Bearer {repository.provider.token}"
    else:
        logger.debug("GitLab API key is not set for provider '%s'. Using unauthenticated request.", repository.provider.url)
    return headers


async def fetch_gitlab_issue(repository: Repository, issue_number: int) -> Issue:
    """
    Fetch an issue from a GitLab instance.
    Args:
        repository (Repository): The repository to fetch the issue from.
        issue_number (int): The issue number.
    Returns:
        Issue: An Issue object containing the issue details.
    Raises:
        aiohttp.ClientResponseError: If the request to the Forgejo API fails.
        ValueError: If the response from the Forgejo API is empty
    """
    url = f"{repository.provider.api_url}/projects/{repository.owner}%2F{repository.name}/issues/{issue_number}"
    async with aiohttp.ClientSession() as session:
        async with session.get(url, headers=_populate_headers(repository)) as response:
            if response.status != 200:
                raise aiohttp.ClientResponseError(
                    request_info=response.request_info,
                    history=response.history,
                    status=response.status,
                    message=f"Failed to fetch issue '{issue_number}' from '{repository.url}'.",
                )
            data = await response.json()

    if data is None:
        raise ValueError("Received empty response from the GitLab API.")

    if data.get("state", "opened") == "closed":
        issue_type = "issue_closed"
    else:
        issue_type = "issue"

    return Issue(
        repository=repository,
        number=data["iid"],
        author=data["author"]["username"],
        author_avatar=data["author"]["avatar_url"],
        author_url=data["author"]["web_url"],
        link=data["web_url"],
        title=data["title"],
        body=data["description"],
        type=issue_type,
        labels=data.get("labels", []),
        draft=False,
        creation_date=data["created_at"],
        milestone=data.get("milestone", {}).get("title") if data.get("milestone") is not None else None,
        response=response,
    )


async def fetch_gitlab_merge_request(repository: Repository, merge_request_number: int) -> Issue:
    """
    Fetch a merge request from a GitLab instance.
    Args:
        repository (Repository): The repository to fetch the merge request from.
        merge_request_number (int): The merge request number.
    Returns:
        Issue: An Issue object containing the merge request details.
    Raises:
        aiohttp.ClientResponseError: If the request to the GitLab API fails.
        ValueError: If the response from the GitLab API is empty
    """
    url = f"{repository.provider.api_url}/projects/{repository.owner}%2F{repository.name}/merge_requests/{merge_request_number}"
    async with aiohttp.ClientSession() as session:
        async with session.get(url, headers=_populate_headers(repository)) as response:
            if response.status != 200:
                raise aiohttp.ClientResponseError(
                    request_info=response.request_info,
                    history=response.history,
                    status=response.status,
                    message=f"Failed to fetch merge request '{merge_request_number}' from '{repository.url}'.",
                )
            data = await response.json()

    if data is None:
        raise ValueError("Received empty response from the GitLab API.")

    state = data.get("state", "opened")
    if state == "merged":
        issue_type = "pull_request_merged"
    elif state == "closed":
        issue_type = "pull_request_closed"
    elif data.get("draft", False) is True:
        issue_type = "pull_request_draft"
    else:
        issue_type = "pull_request"

    return Issue(
        repository=repository,
        number=data["iid"],
        author=data["author"]["username"],
        author_avatar=data["author"]["avatar_url"],
        author_url=data["author"]["web_url"],
        link=data["web_url"],
        title=data["title"],
        body=data["description"],
        type=issue_type,
        labels=data.get("labels", []),
        draft=data.get("draft", False),
        creation_date=data["created_at"],
        milestone=data.get("milestone", {}).get("title") if data.get("milestone") is not None else None,
        merge_date=data.get("merged_at"),
        response=response,
    )