// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.

//! An object store implementation for Azure blob storage
//!
//! ## Streaming uploads
//!
//! [ObjectStore::put_multipart] will upload data in blocks and write a blob from those blocks.
//!
//! Unused blocks will automatically be dropped after 7 days.
use crate::{
    multipart::{MultipartStore, PartId},
    path::Path,
    signer::Signer,
    GetOptions, GetResult, ListResult, MultipartId, MultipartUpload, ObjectMeta, ObjectStore,
    PutMultipartOpts, PutOptions, PutPayload, PutResult, Result, UploadPart,
};
use async_trait::async_trait;
use futures::stream::{BoxStream, StreamExt, TryStreamExt};
use reqwest::Method;
use std::fmt::Debug;
use std::sync::Arc;
use std::time::Duration;
use url::Url;

use crate::client::get::GetClientExt;
use crate::client::list::ListClientExt;
use crate::client::CredentialProvider;
pub use credential::{authority_hosts, AzureAccessKey, AzureAuthorizer};

mod builder;
mod client;
mod credential;

/// [`CredentialProvider`] for [`MicrosoftAzure`]
pub type AzureCredentialProvider = Arc<dyn CredentialProvider<Credential = AzureCredential>>;
use crate::azure::client::AzureClient;
use crate::client::parts::Parts;
pub use builder::{AzureConfigKey, MicrosoftAzureBuilder};
pub use credential::AzureCredential;

const STORE: &str = "MicrosoftAzure";

/// Interface for [Microsoft Azure Blob Storage](https://azure.microsoft.com/en-us/services/storage/blobs/).
#[derive(Debug)]
pub struct MicrosoftAzure {
    client: Arc<AzureClient>,
}

impl MicrosoftAzure {
    /// Returns the [`AzureCredentialProvider`] used by [`MicrosoftAzure`]
    pub fn credentials(&self) -> &AzureCredentialProvider {
        &self.client.config().credentials
    }

    /// Create a full URL to the resource specified by `path` with this instance's configuration.
    fn path_url(&self, path: &Path) -> Url {
        self.client.config().path_url(path)
    }
}

impl std::fmt::Display for MicrosoftAzure {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "MicrosoftAzure {{ account: {}, container: {} }}",
            self.client.config().account,
            self.client.config().container
        )
    }
}

#[async_trait]
impl ObjectStore for MicrosoftAzure {
    async fn put_opts(
        &self,
        location: &Path,
        payload: PutPayload,
        opts: PutOptions,
    ) -> Result<PutResult> {
        self.client.put_blob(location, payload, opts).await
    }

    async fn put_multipart_opts(
        &self,
        location: &Path,
        opts: PutMultipartOpts,
    ) -> Result<Box<dyn MultipartUpload>> {
        Ok(Box::new(AzureMultiPartUpload {
            part_idx: 0,
            opts,
            state: Arc::new(UploadState {
                client: Arc::clone(&self.client),
                location: location.clone(),
                parts: Default::default(),
            }),
        }))
    }

    async fn get_opts(&self, location: &Path, options: GetOptions) -> Result<GetResult> {
        self.client.get_opts(location, options).await
    }

    async fn delete(&self, location: &Path) -> Result<()> {
        self.client.delete_request(location, &()).await
    }

    fn list(&self, prefix: Option<&Path>) -> BoxStream<'static, Result<ObjectMeta>> {
        self.client.list(prefix)
    }
    fn delete_stream<'a>(
        &'a self,
        locations: BoxStream<'a, Result<Path>>,
    ) -> BoxStream<'a, Result<Path>> {
        locations
            .try_chunks(256)
            .map(move |locations| async {
                // Early return the error. We ignore the paths that have already been
                // collected into the chunk.
                let locations = locations.map_err(|e| e.1)?;
                self.client
                    .bulk_delete_request(locations)
                    .await
                    .map(futures::stream::iter)
            })
            .buffered(20)
            .try_flatten()
            .boxed()
    }

    async fn list_with_delimiter(&self, prefix: Option<&Path>) -> Result<ListResult> {
        self.client.list_with_delimiter(prefix).await
    }

    async fn copy(&self, from: &Path, to: &Path) -> Result<()> {
        self.client.copy_request(from, to, true).await
    }

    async fn copy_if_not_exists(&self, from: &Path, to: &Path) -> Result<()> {
        self.client.copy_request(from, to, false).await
    }
}

#[async_trait]
impl Signer for MicrosoftAzure {
    /// Create a URL containing the relevant [Service SAS] query parameters that authorize a request
    /// via `method` to the resource at `path` valid for the duration specified in `expires_in`.
    ///
    /// [Service SAS]: https://learn.microsoft.com/en-us/rest/api/storageservices/create-service-sas
    ///
    /// # Example
    ///
    /// This example returns a URL that will enable a user to upload a file to
    /// "some-folder/some-file.txt" in the next hour.
    ///
    /// ```
    /// # async fn example() -> Result<(), Box<dyn std::error::Error>> {
    /// # use object_store::{azure::MicrosoftAzureBuilder, path::Path, signer::Signer};
    /// # use reqwest::Method;
    /// # use std::time::Duration;
    /// #
    /// let azure = MicrosoftAzureBuilder::new()
    ///     .with_account("my-account")
    ///     .with_access_key("my-access-key")
    ///     .with_container_name("my-container")
    ///     .build()?;
    ///
    /// let url = azure.signed_url(
    ///     Method::PUT,
    ///     &Path::from("some-folder/some-file.txt"),
    ///     Duration::from_secs(60 * 60)
    /// ).await?;
    /// #     Ok(())
    /// # }
    /// ```
    async fn signed_url(&self, method: Method, path: &Path, expires_in: Duration) -> Result<Url> {
        let mut url = self.path_url(path);
        let signer = self.client.signer(expires_in).await?;
        signer.sign(&method, &mut url)?;
        Ok(url)
    }

    async fn signed_urls(
        &self,
        method: Method,
        paths: &[Path],
        expires_in: Duration,
    ) -> Result<Vec<Url>> {
        let mut urls = Vec::with_capacity(paths.len());
        let signer = self.client.signer(expires_in).await?;
        for path in paths {
            let mut url = self.path_url(path);
            signer.sign(&method, &mut url)?;
            urls.push(url);
        }
        Ok(urls)
    }
}

/// Relevant docs: <https://azure.github.io/Storage/docs/application-and-user-data/basics/azure-blob-storage-upload-apis/>
/// In Azure Blob Store, parts are "blocks"
/// put_multipart_part -> PUT block
/// complete -> PUT block list
/// abort -> No equivalent; blocks are simply dropped after 7 days
#[derive(Debug)]
struct AzureMultiPartUpload {
    part_idx: usize,
    state: Arc<UploadState>,
    opts: PutMultipartOpts,
}

#[derive(Debug)]
struct UploadState {
    location: Path,
    parts: Parts,
    client: Arc<AzureClient>,
}

#[async_trait]
impl MultipartUpload for AzureMultiPartUpload {
    fn put_part(&mut self, data: PutPayload) -> UploadPart {
        let idx = self.part_idx;
        self.part_idx += 1;
        let state = Arc::clone(&self.state);
        Box::pin(async move {
            let part = state.client.put_block(&state.location, idx, data).await?;
            state.parts.put(idx, part);
            Ok(())
        })
    }

    async fn complete(&mut self) -> Result<PutResult> {
        let parts = self.state.parts.finish(self.part_idx)?;

        self.state
            .client
            .put_block_list(&self.state.location, parts, std::mem::take(&mut self.opts))
            .await
    }

    async fn abort(&mut self) -> Result<()> {
        // Nothing to do
        Ok(())
    }
}

#[async_trait]
impl MultipartStore for MicrosoftAzure {
    async fn create_multipart(&self, _: &Path) -> Result<MultipartId> {
        Ok(String::new())
    }

    async fn put_part(
        &self,
        path: &Path,
        _: &MultipartId,
        part_idx: usize,
        data: PutPayload,
    ) -> Result<PartId> {
        self.client.put_block(path, part_idx, data).await
    }

    async fn complete_multipart(
        &self,
        path: &Path,
        _: &MultipartId,
        parts: Vec<PartId>,
    ) -> Result<PutResult> {
        self.client
            .put_block_list(path, parts, Default::default())
            .await
    }

    async fn abort_multipart(&self, _: &Path, _: &MultipartId) -> Result<()> {
        // There is no way to drop blocks that have been uploaded. Instead, they simply
        // expire in 7 days.
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::integration::*;
    use crate::tests::*;
    use bytes::Bytes;

    #[tokio::test]
    async fn azure_blob_test() {
        maybe_skip_integration!();
        let integration = MicrosoftAzureBuilder::from_env().build().unwrap();

        put_get_delete_list(&integration).await;
        get_opts(&integration).await;
        list_uses_directories_correctly(&integration).await;
        list_with_delimiter(&integration).await;
        rename_and_copy(&integration).await;
        copy_if_not_exists(&integration).await;
        stream_get(&integration).await;
        put_opts(&integration, true).await;
        multipart(&integration, &integration).await;
        multipart_race_condition(&integration, false).await;
        multipart_out_of_order(&integration).await;
        signing(&integration).await;

        let validate = !integration.client.config().disable_tagging;
        tagging(
            Arc::new(MicrosoftAzure {
                client: Arc::clone(&integration.client),
            }),
            validate,
            |p| {
                let client = Arc::clone(&integration.client);
                async move { client.get_blob_tagging(&p).await }
            },
        )
        .await;

        // Azurite doesn't support attributes properly
        if !integration.client.config().is_emulator {
            put_get_attributes(&integration).await;
        }
    }

    #[ignore = "Used for manual testing against a real storage account."]
    #[tokio::test]
    async fn test_user_delegation_key() {
        let account = std::env::var("AZURE_ACCOUNT_NAME").unwrap();
        let container = std::env::var("AZURE_CONTAINER_NAME").unwrap();
        let client_id = std::env::var("AZURE_CLIENT_ID").unwrap();
        let client_secret = std::env::var("AZURE_CLIENT_SECRET").unwrap();
        let tenant_id = std::env::var("AZURE_TENANT_ID").unwrap();
        let integration = MicrosoftAzureBuilder::new()
            .with_account(account)
            .with_container_name(container)
            .with_client_id(client_id)
            .with_client_secret(client_secret)
            .with_tenant_id(&tenant_id)
            .build()
            .unwrap();

        let data = Bytes::from("hello world");
        let path = Path::from("file.txt");
        integration.put(&path, data.clone().into()).await.unwrap();

        let signed = integration
            .signed_url(Method::GET, &path, Duration::from_secs(60))
            .await
            .unwrap();

        let resp = reqwest::get(signed).await.unwrap();
        let loaded = resp.bytes().await.unwrap();

        assert_eq!(data, loaded);
    }

    #[test]
    fn azure_test_config_get_value() {
        let azure_client_id = "object_store:fake_access_key_id".to_string();
        let azure_storage_account_name = "object_store:fake_secret_key".to_string();
        let azure_storage_token = "object_store:fake_default_region".to_string();
        let builder = MicrosoftAzureBuilder::new()
            .with_config(AzureConfigKey::ClientId, &azure_client_id)
            .with_config(AzureConfigKey::AccountName, &azure_storage_account_name)
            .with_config(AzureConfigKey::Token, &azure_storage_token);

        assert_eq!(
            builder.get_config_value(&AzureConfigKey::ClientId).unwrap(),
            azure_client_id
        );
        assert_eq!(
            builder
                .get_config_value(&AzureConfigKey::AccountName)
                .unwrap(),
            azure_storage_account_name
        );
        assert_eq!(
            builder.get_config_value(&AzureConfigKey::Token).unwrap(),
            azure_storage_token
        );
    }
}
