// Licensed to the Apache Software Foundation (ASF) under one
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// 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.

use std::fmt::Debug;

use serde::Deserialize;
use serde::Serialize;

use super::AZDLS_SCHEME;
use super::backend::AzdlsBuilder;

/// Azure Data Lake Storage Gen2 Support.
#[derive(Default, Serialize, Deserialize, Clone, PartialEq, Eq)]
#[serde(default)]
pub struct AzdlsConfig {
    /// Root of this backend.
    pub root: Option<String>,
    /// Filesystem name of this backend.
    pub filesystem: String,
    /// Endpoint of this backend.
    pub endpoint: Option<String>,
    /// Account name of this backend.
    pub account_name: Option<String>,
    /// Account key of this backend.
    /// - required for shared_key authentication
    pub account_key: Option<String>,
    /// client_secret
    /// The client secret of the service principal.
    /// - required for client_credentials authentication
    pub client_secret: Option<String>,
    /// tenant_id
    /// The tenant id of the service principal.
    /// - required for client_credentials authentication
    pub tenant_id: Option<String>,
    /// client_id
    /// The client id of the service principal.
    /// - required for client_credentials authentication
    pub client_id: Option<String>,
    /// sas_token
    /// The shared access signature token.
    /// - required for sas authentication
    pub sas_token: Option<String>,
    /// authority_host
    /// The authority host of the service principal.
    /// - required for client_credentials authentication
    /// - default value: `https://login.microsoftonline.com`
    pub authority_host: Option<String>,
    /// Whether hierarchical namespace (HNS) is enabled for the storage account.
    /// When enabled, recursive deletion can use pagination to avoid timeouts on large directories.
    /// - default value: `false`
    pub enable_hns: bool,
}

impl Debug for AzdlsConfig {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("AzdlsConfig")
            .field("root", &self.root)
            .field("filesystem", &self.filesystem)
            .field("endpoint", &self.endpoint)
            .finish_non_exhaustive()
    }
}

impl opendal_core::Configurator for AzdlsConfig {
    type Builder = AzdlsBuilder;

    fn from_uri(uri: &opendal_core::OperatorUri) -> opendal_core::Result<Self> {
        let mut map = uri.options().clone();
        if let Some(authority) = uri.authority() {
            map.insert("endpoint".to_string(), format!("https://{authority}"));
        }

        if let Some(account) = uri
            .name()
            .and_then(|host| host.split('.').next())
            .filter(|account| !account.is_empty())
        {
            map.entry("account_name".to_string())
                .or_insert_with(|| account.to_string());
        }

        if let Some(root) = uri.root() {
            if let Some((filesystem, rest)) = root.split_once('/') {
                if filesystem.is_empty() {
                    return Err(opendal_core::Error::new(
                        opendal_core::ErrorKind::ConfigInvalid,
                        "filesystem is required in uri path",
                    )
                    .with_context("service", AZDLS_SCHEME));
                }
                map.insert("filesystem".to_string(), filesystem.to_string());
                if !rest.is_empty() {
                    map.insert("root".to_string(), rest.to_string());
                }
            } else if !root.is_empty() {
                map.insert("filesystem".to_string(), root.to_string());
            }
        }

        if !map.contains_key("filesystem") {
            return Err(opendal_core::Error::new(
                opendal_core::ErrorKind::ConfigInvalid,
                "filesystem is required",
            )
            .with_context("service", AZDLS_SCHEME));
        }

        Self::from_iter(map)
    }

    #[allow(deprecated)]
    fn into_builder(self) -> Self::Builder {
        AzdlsBuilder { config: self }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use opendal_core::Configurator;
    use opendal_core::OperatorUri;

    #[test]
    fn from_uri_sets_endpoint_filesystem_root_and_account() {
        let uri = OperatorUri::new(
            "azdls://account.dfs.core.windows.net/fs/data/2024",
            Vec::<(String, String)>::new(),
        )
        .unwrap();

        let cfg = AzdlsConfig::from_uri(&uri).unwrap();
        assert_eq!(
            cfg.endpoint.as_deref(),
            Some("https://account.dfs.core.windows.net")
        );
        assert_eq!(cfg.filesystem, "fs".to_string());
        assert_eq!(cfg.root.as_deref(), Some("data/2024"));
        assert_eq!(cfg.account_name.as_deref(), Some("account"));
    }

    #[test]
    fn from_uri_accepts_filesystem_from_query() {
        let uri = OperatorUri::new(
            "azdls://account.dfs.core.windows.net",
            vec![("filesystem".to_string(), "logs".to_string())],
        )
        .unwrap();

        let cfg = AzdlsConfig::from_uri(&uri).unwrap();
        assert_eq!(cfg.filesystem, "logs".to_string());
    }
}
