import os
import uuid
import warnings
from concurrent.futures import ThreadPoolExecutor
from functools import wraps
from pathlib import Path
from typing import Any, Dict, List, Literal, Optional, TypedDict, Union

import gradio as gr
from fastapi import BackgroundTasks, HTTPException, Response, status
from huggingface_hub import (
    SpaceHardware,
    SpaceStorage,
    WebhookPayload,
    WebhooksServer,
    add_space_secret,
    add_space_variable,
    comment_discussion,
    create_repo,
    delete_repo,
    get_discussion_details,
    get_repo_discussions,
    get_space_runtime,
    get_space_variables,
    repo_exists,
    request_space_hardware,
    request_space_storage,
    snapshot_download,
    space_info,
    upload_folder,
)
from huggingface_hub.repocard import RepoCard
from huggingface_hub.utils import (
    RepositoryNotFoundError,
    build_hf_headers,
    get_session,
    hf_raise_for_status,
)
from requests import HTTPError

SPACE_ID = os.environ.get("SPACE_ID")
IS_EPHEMERAL_SPACE = SPACE_ID is not None and "-ci-pr-" in SPACE_ID
WEBHOOK_SECRET = os.environ.get("SPACE_CI_SECRET")

if SPACE_ID is not None:  # If running in a Space (i.e. not locally)
    if WEBHOOK_SECRET is None:  # No secret set yet => generate one => restart space
        WEBHOOK_SECRET = str(uuid.uuid4())
        add_space_secret(
            repo_id=SPACE_ID,
            key="SPACE_CI_SECRET",
            value=WEBHOOK_SECRET,
            description="This value is used by the SpaceCI. It is automatically generated and should not be changed.",
        )

EPHEMERAL_SPACES_CONFIG: Dict[str, Any] = {}

# Draft and open PRs are considered as active (in opposition to closed and merged PRs)
ACTIVE_PR_STATUS = ("draft", "open")


def enable_space_ci() -> None:
    """Enable Space CI for the current Space based on config from the README.md file.

    Example:
    ```py
    import gradio as gr
    from gradio_space_ci import enable_space_ci

    enable_space_ci()

    with gr.Blocks() as demo:
        ...

    demo.launch()
    ```
    """
    if SPACE_ID is None:
        print("Not in a Space: Space CI disabled.")
        return

    if IS_EPHEMERAL_SPACE:
        print("In an ephemeral Space: Space CI disabled.")
        return

    card = RepoCard.load(repo_id_or_path=SPACE_ID, repo_type="space")
    config = card.data.get("space_ci", {})
    print(f"Enabling Space CI with config from README: {config}")

    old_launch = gr.Blocks.launch

    @wraps(gr.Blocks.launch)
    def new_launch(self: gr.Blocks, *args, **kwargs) -> None:
        server = configure_space_ci(
            blocks=self,
            trusted_authors=config.get("trusted_authors"),
            private=config.get("private", "auto"),
            variables=config.get("variables", "auto"),
            secrets=config.get("secrets"),
            hardware=config.get("hardware"),
            storage=config.get("storage"),
        )
        # De-monkey patch gradio (otherwise it will be called recursively)
        gr.Blocks.launch = old_launch
        server.launch(*args, *kwargs)

    # Monkey patch gradio
    gr.Blocks.launch = new_launch


def configure_space_ci(
    blocks: Optional["gr.Blocks"] = None,
    trusted_authors: Optional[List[str]] = None,
    private: Union[bool, Literal["auto"]] = "auto",
    variables: Union[Dict[str, str], Literal["auto"]] = "auto",
    secrets: Optional[List[str]] = None,
    hardware: Union[SpaceHardware, Literal["auto"], None] = None,
    storage: Union[SpaceStorage, Literal["auto"], None] = None,
) -> WebhooksServer:
    if SPACE_ID is None or IS_EPHEMERAL_SPACE:
        # Runs locally => don't configure webhook
        # Runs in an ephemeral Space => don't configure webhook
        return WebhooksServer(ui=blocks)

    # Authors
    trusted_authors = trusted_authors or []
    namespace = SPACE_ID.split("/")[0]
    try:  # Check if namespace is an organization => in this case all members are allowed to trigger CI by default
        response = get_session().get(
            f"https://huggingface.co/api/organizations/{namespace}/members", headers=build_hf_headers()
        )
        response.raise_for_status()
        trusted_authors += [user["user"] for user in response.json()]
    except Exception:  # Otherwise, it's a single user => only this user is allowed to trigger CI by default
        trusted_authors += [namespace]
    trusted_authors = sorted(set(trusted_authors))
    EPHEMERAL_SPACES_CONFIG["trusted_authors"] = trusted_authors

    # Private
    if private == "auto":
        private = space_info(SPACE_ID).private
    EPHEMERAL_SPACES_CONFIG["private"] = private

    # Variables
    if variables == "auto":
        variables = {value.key: value.value for value in get_space_variables(SPACE_ID).values()}
    EPHEMERAL_SPACES_CONFIG["variables"] = variables

    # Secrets
    secrets_with_values: Dict[str, str] = {}
    if secrets is not None:
        for secret in secrets:
            secret_value = os.environ.get(secret)
            if secret_value is None:
                warnings.warn(f"Secret {secret} not found in environment variables. Will skip it in ephemeral Space.")
                continue
            secrets_with_values[secret] = secret_value
    EPHEMERAL_SPACES_CONFIG["secrets"] = secrets_with_values

    # Hardware and storage
    if hardware == "auto" or storage == "auto":
        runtime = get_space_runtime(SPACE_ID)
        if hardware == "auto":
            hardware = runtime.hardware
        if storage == "auto":
            storage = runtime.storage
    EPHEMERAL_SPACES_CONFIG["hardware"] = hardware
    EPHEMERAL_SPACES_CONFIG["storage"] = storage

    # Summary
    print(
        "Ephemeral Spaces config:"
        f"\n  - trusted authors: {trusted_authors}"
        f"\n  - private: {private}"
        f"\n  - secrets: {', '.join(sorted(secrets_with_values.keys()))}"
        f"\n  - variables: {variables}"
        f"\n  - storage: {storage}"
        f"\n  - hardware: {hardware}"
    )

    # Configure webhook
    server = WebhooksServer(ui=blocks, webhook_secret=WEBHOOK_SECRET)
    server.add_webhook()(trigger_ci_on_pr)
    configure_webhook_on_hub()

    # Recover missed webhooks (loop through PRs in the background)
    background_pool.submit(recover_after_restart, space_id=SPACE_ID)

    return server


###
# Recovery logic
###
# Check if there are any PRs that need to be synced.
# We might have missed some events while the server was down.
# => called once at startup (see configure_space_ci)

background_pool = ThreadPoolExecutor(max_workers=1)


def recover_after_restart(space_id: str) -> None:
    print("Looping through PRs to check if any needs to be synced.")
    for discussion in get_repo_discussions(repo_id=space_id, repo_type="space", discussion_type="pull_request"):
        if discussion.status in ACTIVE_PR_STATUS:
            if not is_pr_synced(space_id=space_id, pr_num=discussion.num):
                # Found a PR that is not yet synced
                print(f"Recovery. Found an open PR that is not synced: {discussion.url}. Syncing it.")
                background_pool.submit(sync_ci_space, space_id=space_id, pr_num=discussion.num)
        if discussion.status == "merged" or discussion.status == "closed":
            ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=discussion.num)
            if repo_exists(repo_id=ci_space_id, repo_type="space"):
                # Found a PR for which the CI space has not been deleted
                print(f"Recovery. Found a closed PR with an active CI space: {discussion.url}. Deleting it.")
                background_pool.submit(delete_ci_space, space_id=space_id, pr_num=discussion.num)


###
# Define webhook on the Hub logic
###


def configure_webhook_on_hub():
    url = "https://" + os.environ.get("SPACE_HOST").strip("/") + "/webhooks/trigger_ci_on_pr"

    # Check if webhook already exists
    webhooks = list_webhooks()
    for webhook in webhooks:
        if webhook["url"] == url:
            print("Webhook already configured")
            return

    # If not => create it
    create_webhook(
        watched=[{"type": "space", "name": SPACE_ID}], url=url, domains=["repo", "discussion"], secret=WEBHOOK_SECRET
    )
    print("New webhook already configured!")


###
# Webhook logic
###


async def trigger_ci_on_pr(payload: WebhookPayload, task_queue: BackgroundTasks):
    if payload.repo.type != "space":
        raise HTTPException(400, f"Must be a Space, not {payload.repo.type}")

    space_id = payload.repo.name

    has_task = False
    if (
        # Means "a new PR has been opened"
        payload.event.scope.startswith("discussion")
        and payload.event.action == "create"
        and payload.discussion is not None
        and payload.discussion.isPullRequest
        and payload.discussion.status in ACTIVE_PR_STATUS
    ):
        if not is_pr_synced(space_id=space_id, pr_num=payload.discussion.num):
            # New PR! Sync task scheduled
            task_queue.add_task(sync_ci_space, space_id=space_id, pr_num=payload.discussion.num)
            has_task = True
    elif (
        # Means "a PR has been merged or closed"
        payload.event.scope.startswith("discussion")
        and payload.event.action == "update"
        and payload.discussion is not None
        and payload.discussion.isPullRequest
        and (payload.discussion.status == "merged" or payload.discussion.status == "closed")
    ):
        task_queue.add_task(
            delete_ci_space,
            space_id=space_id,
            pr_num=payload.discussion.num,
        )
        has_task = True
    elif (
        # Means "some content has been pushed to the Space" (any branch)
        payload.event.scope.startswith("repo.content") and payload.event.action == "update"
    ):
        # New repo change. Is it a commit on a PR?
        # => loop through all PRs and check if new changes happened
        for discussion in get_repo_discussions(repo_id=space_id, repo_type="space"):
            if discussion.is_pull_request and discussion.status in ACTIVE_PR_STATUS:
                if not is_pr_synced(space_id=space_id, pr_num=discussion.num):
                    # Found a PR that is not yet synced
                    task_queue.add_task(sync_ci_space, space_id=space_id, pr_num=discussion.num)
                    has_task = True

    if has_task:
        return Response("Task scheduled to sync/delete Space", status_code=status.HTTP_202_ACCEPTED)
    else:
        return Response("No task scheduled", status_code=status.HTTP_200_OK)


###
# Internal logic
###


def is_pr_synced(space_id: str, pr_num: int) -> bool:
    # What is the last synced commit for this PR?
    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)
    try:
        card = RepoCard.load(repo_id_or_path=ci_space_id, repo_type="space")
        last_synced_sha = getattr(card.data, "synced_sha", None)
    except HTTPError:
        return False

    # What is the last commit id for this PR?
    info = space_info(repo_id=space_id, revision=f"refs/pr/{pr_num}")
    last_pr_sha = info.sha

    # Is it up to date ?
    return last_synced_sha == last_pr_sha


def sync_ci_space(space_id: str, pr_num: int) -> None:
    print(f"New task: sync ephemeral env for {space_id} (PR {pr_num})")
    if is_pr_synced(space_id=space_id, pr_num=pr_num):
        print("Already synced. Nothing to do.")
        return

    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)

    # Create a temporary space for CI if didn't exist
    is_new = create_ephemeral_space(space_id=space_id, pr_num=pr_num)

    # Configure ephemeral Space if trusted author
    is_configured = False
    if is_new:
        is_configured = configure_ephemeral_space(space_id=space_id, pr_num=pr_num)

    # Download space codebase from PR revision
    snapshot_path = Path(snapshot_download(repo_id=space_id, revision=f"refs/pr/{pr_num}", repo_type="space"))

    # Overwrite README file in cache (/!\)
    readme_path = snapshot_path / "README.md"
    card = RepoCard.load(readme_path)
    setattr(card.data, "synced_sha", snapshot_path.name)  # latest sha
    card.data.title = f"{card.data.title} (ephemeral #{pr_num})"
    card.save(readme_path)

    # Sync space codebase with PR revision
    upload_folder(
        repo_id=ci_space_id,
        repo_type="space",
        commit_message=f"Sync CI Space with PR {pr_num}.",
        folder_path=snapshot_path,
        delete_patterns="*",
    )

    # Delete readme file from cache (just in case)
    readme_path.unlink(missing_ok=True)

    # Post a comment on the PR
    if is_new and is_configured:
        notify_pr(space_id=space_id, pr_num=pr_num, action="created_and_configured")
    elif is_new:
        notify_pr(space_id=space_id, pr_num=pr_num, action="created_not_configured")
    else:
        notify_pr(space_id=space_id, pr_num=pr_num, action="updated")


def create_ephemeral_space(space_id: str, pr_num: int) -> bool:
    # Config values
    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)
    private: bool = EPHEMERAL_SPACES_CONFIG["private"]

    # Create space
    try:
        create_repo(
            ci_space_id,
            repo_type="space",
            space_sdk="docker",  # Will be overwritten by sync
            private=private,
            exist_ok=False,
        )
        return True
    except HTTPError as err:
        if err.response is not None and err.response.status_code == 409:  # already exists
            return False
        else:
            raise


def configure_ephemeral_space(space_id: str, pr_num: int) -> bool:
    # Config values
    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)
    trusted_authors: List[str] = EPHEMERAL_SPACES_CONFIG["trusted_authors"]
    variables: Dict[str, str] = EPHEMERAL_SPACES_CONFIG["variables"]
    secrets: Dict[str, str] = EPHEMERAL_SPACES_CONFIG["secrets"]
    hardware: Optional[SpaceHardware] = EPHEMERAL_SPACES_CONFIG["hardware"]
    storage: Optional[SpaceHardware] = EPHEMERAL_SPACES_CONFIG["storage"]

    # Check if trusted author
    details = get_discussion_details(repo_id=space_id, repo_type="space", discussion_num=pr_num)
    if details.author not in trusted_authors:
        return False  # not a trusted author => do NOT set secrets, hardware, storage, etc.

    # Configure space
    for key, value in variables.items():
        add_space_variable(ci_space_id, key, value)
    for key, value in secrets.items():
        add_space_secret(ci_space_id, key, value)

    # Request hardware/storage for space
    if hardware is not None and hardware != SpaceHardware.CPU_BASIC:
        request_space_hardware(ci_space_id, hardware, sleep_time=5 * 60)  # sleep after 5min on PR Spaces with GPU
    if storage is not None:
        request_space_storage(ci_space_id, storage)

    return True


def delete_ci_space(space_id: str, pr_num: int) -> None:
    print(f"New task: delete ephemeral env for {space_id} (PR {pr_num})")

    # Delete
    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)
    try:
        delete_repo(repo_id=ci_space_id, repo_type="space")
    except RepositoryNotFoundError:
        # Repo did not exist: no need to notify
        return

    # Notify about deletion
    notify_pr(space_id=space_id, pr_num=pr_num, action="deleted")


def notify_pr(
    space_id: str,
    pr_num: int,
    action: Literal["created_not_configured", "created_and_configured", "updated", "deleted"],
) -> None:
    ci_space_id = _get_ci_space_id(space_id=space_id, pr_num=pr_num)
    if action == "created_not_configured":
        comment = NOTIFICATION_TEMPLATE_CREATED_NOT_CONFIGURED.format(ci_space_id=ci_space_id)
    elif action == "created_and_configured":
        comment = NOTIFICATION_TEMPLATE_CREATED_AND_CONFIGURED.format(ci_space_id=ci_space_id)
    elif action == "updated":
        comment = NOTIFICATION_TEMPLATE_UPDATED.format(ci_space_id=ci_space_id)
    elif action == "deleted":
        comment = NOTIFICATION_TEMPLATE_DELETED
    else:
        raise ValueError(f"Status {action} not handled.")

    comment_discussion(repo_id=space_id, repo_type="space", discussion_num=pr_num, comment=comment)


def _get_ci_space_id(space_id: str, pr_num: int) -> str:
    return f"{space_id}-ci-pr-{pr_num}"


NOTIFICATION_TEMPLATE_CREATED_AND_CONFIGURED = """\
Following the creation of this PR, an ephemeral Space [{ci_space_id}](https://huggingface.co/spaces/{ci_space_id}) has been started. Any changes pushed to this PR will be synced with the test Space.
Since this PR has been created by a trusted author, the ephemeral Space has been configured with the correct hardware, storage, and secrets.
_(This is an automated message.)_
"""

NOTIFICATION_TEMPLATE_CREATED_NOT_CONFIGURED = """\
Following the creation of this PR, an ephemeral Space [{ci_space_id}](https://huggingface.co/spaces/{ci_space_id}) has been started. Any changes pushed to this PR will be synced with the test Space.
Since this PR has not been created by a trusted author, the ephemeral Space has not been configured with the correct hardware, storage, and secrets. An admin must configure it manually.
_(This is an automated message.)_
"""

NOTIFICATION_TEMPLATE_UPDATED = """\
Following new commits that happened in this PR, the ephemeral Space [{ci_space_id}](https://huggingface.co/spaces/{ci_space_id}) has been updated.
_(This is an automated message.)_
"""

NOTIFICATION_TEMPLATE_DELETED = """\
PR is now merged/closed. The ephemeral Space has been deleted.
_(This is an automated message.)_
"""

### TO MOVE TO ITS OWN MODULE
# Taken from https://github.com/huggingface/huggingface_hub/issues/1808#issuecomment-1802341663


headers = build_hf_headers()


class WatchedItem(TypedDict):
    # Examples:
    #     {"type": "user", "name": "julien-c"}
    #     {"type": "org", "name": "HuggingFaceH4"}
    #     {"type": "model", "name": "HuggingFaceH4/zephyr-7b-beta"}
    #     {"type": "dataset", "name": "HuggingFaceH4/ultrachat_200k"}
    #     {"type": "space", "name": "HuggingFaceH4/zephyr-chat"}
    type: Literal["model", "dataset", "space", "org", "user"]
    name: str


# Do you want to subscribe to repo updates (code changes), discussion updates (issues, PRs, comments), or both?
DOMAIN_T = Literal["repo", "discussion"]


def get_webhook(webhook_id: str) -> Dict:
    """Get a webhook by its id."""
    response = get_session().get(f"https://huggingface.co/api/settings/webhooks/{webhook_id}", headers=headers)
    hf_raise_for_status(response)
    return response.json()


def list_webhooks() -> List[Dict]:
    """List all configured webhooks."""
    response = get_session().get("https://huggingface.co/api/settings/webhooks", headers=headers)
    hf_raise_for_status(response)
    return response.json()


def create_webhook(watched: List[WatchedItem], url: str, domains: List[DOMAIN_T], secret: Optional[str]) -> Dict:
    """Create a new webhook.

    Args:
        watched (List[WatchedItem]):
            List of items to watch. It an be users, orgs, models, datasets or spaces.
            See `WatchedItem` for more details.
        url (str):
            URL to send the payload to.
        domains (List[Literal["repo", "discussion"]]):
            List of domains to watch. It can be "repo", "discussion" or both.
        secret (str, optional):
            Secret to use to sign the payload.

    Returns:
        dict: The created webhook.

    Example:
        ```python
        >>> payload = create_webhook(
        ...     watched=[{"type": "user", "name": "julien-c"}, {"type": "org", "name": "HuggingFaceH4"}],
        ...     url="https://webhook.site/a2176e82-5720-43ee-9e06-f91cb4c91548",
        ...     domains=["repo", "discussion"],
        ...     secret="my-secret",
        ... )
        {
            "webhook": {
                "id": "654bbbc16f2ec14d77f109cc",
                "watched": [{"type": "user", "name": "julien-c"}, {"type": "org", "name": "HuggingFaceH4"}],
                "url": "https://webhook.site/a2176e82-5720-43ee-9e06-f91cb4c91548",
                "secret": "my-secret",
                "domains": ["repo", "discussion"],
                "disabled": False,
            },
        }
        ```
    """
    print("Creating webhook")
    print({"watched": watched, "url": url, "domains": domains, "secret": str(type(secret))})

    response = get_session().post(
        "https://huggingface.co/api/settings/webhooks",
        json={"watched": watched, "url": url, "domains": domains, "secret": secret},
        headers=headers,
    )
    hf_raise_for_status(response)
    return response.json()


def update_webhook(
    webhook_id: str, watched: List[WatchedItem], url: str, domains: List[DOMAIN_T], secret: Optional[str]
) -> Dict:
    """Update an existing webhook.

    Exact same usage as `create_webhook` but you must know the `webhook_id`.
    All fields are updated.
    """
    response = get_session().post(
        f"https://huggingface.co/api/settings/webhooks/{webhook_id}",
        json={"watched": watched, "url": url, "domains": domains, "secret": secret},
        headers=headers,
    )
    hf_raise_for_status(response)
    return response.json()


def enable_webhook(webhook_id: str) -> Dict:
    """Enable a webhook (makes it "active")."""
    response = get_session().post(
        f"https://huggingface.co/api/settings/webhooks/{webhook_id}/enable",
        headers=headers,
    )
    hf_raise_for_status(response)
    return response.json()


def disable_webhook(webhook_id: str) -> Dict:
    """Disable a webhook (makes it "disabled")."""
    response = get_session().post(
        f"https://huggingface.co/api/settings/webhooks/{webhook_id}/disable",
        headers=headers,
    )
    hf_raise_for_status(response)
    return response.json()


def delete_webhook(webhook_id: str):
    """Delete a webhook."""
    response = get_session().delete(
        f"https://huggingface.co/api/settings/webhooks/{webhook_id}",
        headers=headers,
    )
    hf_raise_for_status(response)