// 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.

use crate::client::get::GetClient;
use crate::client::header::HeaderConfig;
use crate::client::retry::{self, RetryConfig, RetryExt};
use crate::client::GetOptionsExt;
use crate::path::{Path, DELIMITER};
use crate::util::deserialize_rfc1123;
use crate::{Attribute, Attributes, ClientOptions, GetOptions, ObjectMeta, PutPayload, Result};
use async_trait::async_trait;
use bytes::Buf;
use chrono::{DateTime, Utc};
use hyper::header::{
    CACHE_CONTROL, CONTENT_DISPOSITION, CONTENT_ENCODING, CONTENT_LANGUAGE, CONTENT_LENGTH,
    CONTENT_TYPE,
};
use percent_encoding::percent_decode_str;
use reqwest::{Method, Response, StatusCode};
use serde::Deserialize;
use snafu::{OptionExt, ResultExt, Snafu};
use url::Url;

#[derive(Debug, Snafu)]
enum Error {
    #[snafu(display("Request error: {}", source))]
    Request { source: retry::Error },

    #[snafu(display("Request error: {}", source))]
    Reqwest { source: reqwest::Error },

    #[snafu(display("Range request not supported by {}", href))]
    RangeNotSupported { href: String },

    #[snafu(display("Error decoding PROPFIND response: {}", source))]
    InvalidPropFind { source: quick_xml::de::DeError },

    #[snafu(display("Missing content size for {}", href))]
    MissingSize { href: String },

    #[snafu(display("Error getting properties of \"{}\" got \"{}\"", href, status))]
    PropStatus { href: String, status: String },

    #[snafu(display("Failed to parse href \"{}\": {}", href, source))]
    InvalidHref {
        href: String,
        source: url::ParseError,
    },

    #[snafu(display("Path \"{}\" contained non-unicode characters: {}", path, source))]
    NonUnicode {
        path: String,
        source: std::str::Utf8Error,
    },

    #[snafu(display("Encountered invalid path \"{}\": {}", path, source))]
    InvalidPath {
        path: String,
        source: crate::path::Error,
    },
}

impl From<Error> for crate::Error {
    fn from(err: Error) -> Self {
        Self::Generic {
            store: "HTTP",
            source: Box::new(err),
        }
    }
}

/// Internal client for HttpStore
#[derive(Debug)]
pub struct Client {
    url: Url,
    client: reqwest::Client,
    retry_config: RetryConfig,
    client_options: ClientOptions,
}

impl Client {
    pub fn new(url: Url, client_options: ClientOptions, retry_config: RetryConfig) -> Result<Self> {
        let client = client_options.client()?;
        Ok(Self {
            url,
            retry_config,
            client_options,
            client,
        })
    }

    pub fn base_url(&self) -> &Url {
        &self.url
    }

    fn path_url(&self, location: &Path) -> Url {
        let mut url = self.url.clone();
        url.path_segments_mut().unwrap().extend(location.parts());
        url
    }

    /// Create a directory with `path` using MKCOL
    async fn make_directory(&self, path: &str) -> Result<(), Error> {
        let method = Method::from_bytes(b"MKCOL").unwrap();
        let mut url = self.url.clone();
        url.path_segments_mut()
            .unwrap()
            .extend(path.split(DELIMITER));

        self.client
            .request(method, url)
            .send_retry(&self.retry_config)
            .await
            .context(RequestSnafu)?;

        Ok(())
    }

    /// Recursively create parent directories
    async fn create_parent_directories(&self, location: &Path) -> Result<()> {
        let mut stack = vec![];

        // Walk backwards until a request succeeds
        let mut last_prefix = location.as_ref();
        while let Some((prefix, _)) = last_prefix.rsplit_once(DELIMITER) {
            last_prefix = prefix;

            match self.make_directory(prefix).await {
                Ok(_) => break,
                Err(Error::Request { source })
                    if matches!(source.status(), Some(StatusCode::CONFLICT)) =>
                {
                    // Need to create parent
                    stack.push(prefix)
                }
                Err(e) => return Err(e.into()),
            }
        }

        // Retry the failed requests, which should now succeed
        for prefix in stack.into_iter().rev() {
            self.make_directory(prefix).await?;
        }

        Ok(())
    }

    pub async fn put(
        &self,
        location: &Path,
        payload: PutPayload,
        attributes: Attributes,
    ) -> Result<Response> {
        let mut retry = false;
        loop {
            let url = self.path_url(location);
            let mut builder = self.client.put(url);

            let mut has_content_type = false;
            for (k, v) in &attributes {
                builder = match k {
                    Attribute::CacheControl => builder.header(CACHE_CONTROL, v.as_ref()),
                    Attribute::ContentDisposition => {
                        builder.header(CONTENT_DISPOSITION, v.as_ref())
                    }
                    Attribute::ContentEncoding => builder.header(CONTENT_ENCODING, v.as_ref()),
                    Attribute::ContentLanguage => builder.header(CONTENT_LANGUAGE, v.as_ref()),
                    Attribute::ContentType => {
                        has_content_type = true;
                        builder.header(CONTENT_TYPE, v.as_ref())
                    }
                    // Ignore metadata attributes
                    Attribute::Metadata(_) => builder,
                };
            }

            if !has_content_type {
                if let Some(value) = self.client_options.get_content_type(location) {
                    builder = builder.header(CONTENT_TYPE, value);
                }
            }

            let resp = builder
                .header(CONTENT_LENGTH, payload.content_length())
                .retryable(&self.retry_config)
                .idempotent(true)
                .payload(Some(payload.clone()))
                .send()
                .await;

            match resp {
                Ok(response) => return Ok(response),
                Err(source) => match source.status() {
                    // Some implementations return 404 instead of 409
                    Some(StatusCode::CONFLICT | StatusCode::NOT_FOUND) if !retry => {
                        retry = true;
                        self.create_parent_directories(location).await?
                    }
                    _ => return Err(Error::Request { source }.into()),
                },
            }
        }
    }

    pub async fn list(&self, location: Option<&Path>, depth: &str) -> Result<MultiStatus> {
        let url = location
            .map(|path| self.path_url(path))
            .unwrap_or_else(|| self.url.clone());

        let method = Method::from_bytes(b"PROPFIND").unwrap();
        let result = self
            .client
            .request(method, url)
            .header("Depth", depth)
            .retryable(&self.retry_config)
            .idempotent(true)
            .send()
            .await;

        let response = match result {
            Ok(result) => result.bytes().await.context(ReqwestSnafu)?,
            Err(e) if matches!(e.status(), Some(StatusCode::NOT_FOUND)) => {
                return match depth {
                    "0" => {
                        let path = location.map(|x| x.as_ref()).unwrap_or("");
                        Err(crate::Error::NotFound {
                            path: path.to_string(),
                            source: Box::new(e),
                        })
                    }
                    _ => {
                        // If prefix not found, return empty result set
                        Ok(Default::default())
                    }
                };
            }
            Err(source) => return Err(Error::Request { source }.into()),
        };

        let status = quick_xml::de::from_reader(response.reader()).context(InvalidPropFindSnafu)?;
        Ok(status)
    }

    pub async fn delete(&self, path: &Path) -> Result<()> {
        let url = self.path_url(path);
        self.client
            .delete(url)
            .send_retry(&self.retry_config)
            .await
            .map_err(|source| match source.status() {
                Some(StatusCode::NOT_FOUND) => crate::Error::NotFound {
                    source: Box::new(source),
                    path: path.to_string(),
                },
                _ => Error::Request { source }.into(),
            })?;
        Ok(())
    }

    pub async fn copy(&self, from: &Path, to: &Path, overwrite: bool) -> Result<()> {
        let mut retry = false;
        loop {
            let method = Method::from_bytes(b"COPY").unwrap();

            let mut builder = self
                .client
                .request(method, self.path_url(from))
                .header("Destination", self.path_url(to).as_str());

            if !overwrite {
                // While the Overwrite header appears to duplicate
                // the functionality of the If-Match: * header of HTTP/1.1, If-Match
                // applies only to the Request-URI, and not to the Destination of a COPY
                // or MOVE.
                builder = builder.header("Overwrite", "F");
            }

            return match builder.send_retry(&self.retry_config).await {
                Ok(_) => Ok(()),
                Err(source) => Err(match source.status() {
                    Some(StatusCode::PRECONDITION_FAILED) if !overwrite => {
                        crate::Error::AlreadyExists {
                            path: to.to_string(),
                            source: Box::new(source),
                        }
                    }
                    // Some implementations return 404 instead of 409
                    Some(StatusCode::CONFLICT | StatusCode::NOT_FOUND) if !retry => {
                        retry = true;
                        self.create_parent_directories(to).await?;
                        continue;
                    }
                    _ => Error::Request { source }.into(),
                }),
            };
        }
    }
}

#[async_trait]
impl GetClient for Client {
    const STORE: &'static str = "HTTP";

    /// Override the [`HeaderConfig`] to be less strict to support a
    /// broader range of HTTP servers (#4831)
    const HEADER_CONFIG: HeaderConfig = HeaderConfig {
        etag_required: false,
        last_modified_required: false,
        version_header: None,
        user_defined_metadata_prefix: None,
    };

    async fn get_request(&self, path: &Path, options: GetOptions) -> Result<Response> {
        let url = self.path_url(path);
        let method = match options.head {
            true => Method::HEAD,
            false => Method::GET,
        };
        let has_range = options.range.is_some();
        let builder = self.client.request(method, url);

        let res = builder
            .with_get_options(options)
            .send_retry(&self.retry_config)
            .await
            .map_err(|source| match source.status() {
                // Some stores return METHOD_NOT_ALLOWED for get on directories
                Some(StatusCode::NOT_FOUND | StatusCode::METHOD_NOT_ALLOWED) => {
                    crate::Error::NotFound {
                        source: Box::new(source),
                        path: path.to_string(),
                    }
                }
                _ => Error::Request { source }.into(),
            })?;

        // We expect a 206 Partial Content response if a range was requested
        // a 200 OK response would indicate the server did not fulfill the request
        if has_range && res.status() != StatusCode::PARTIAL_CONTENT {
            return Err(crate::Error::NotSupported {
                source: Box::new(Error::RangeNotSupported {
                    href: path.to_string(),
                }),
            });
        }

        Ok(res)
    }
}

/// The response returned by a PROPFIND request, i.e. list
#[derive(Deserialize, Default)]
pub struct MultiStatus {
    pub response: Vec<MultiStatusResponse>,
}

#[derive(Deserialize)]
pub struct MultiStatusResponse {
    href: String,
    #[serde(rename = "propstat")]
    prop_stat: PropStat,
}

impl MultiStatusResponse {
    /// Returns an error if this response is not OK
    pub fn check_ok(&self) -> Result<()> {
        match self.prop_stat.status.contains("200 OK") {
            true => Ok(()),
            false => Err(Error::PropStatus {
                href: self.href.clone(),
                status: self.prop_stat.status.clone(),
            }
            .into()),
        }
    }

    /// Returns the resolved path of this element relative to `base_url`
    pub fn path(&self, base_url: &Url) -> Result<Path> {
        let url = Url::options()
            .base_url(Some(base_url))
            .parse(&self.href)
            .context(InvalidHrefSnafu { href: &self.href })?;

        // Reverse any percent encoding
        let path = percent_decode_str(url.path())
            .decode_utf8()
            .context(NonUnicodeSnafu { path: url.path() })?;

        Ok(Path::parse(path.as_ref()).context(InvalidPathSnafu { path })?)
    }

    fn size(&self) -> Result<usize> {
        let size = self
            .prop_stat
            .prop
            .content_length
            .context(MissingSizeSnafu { href: &self.href })?;
        Ok(size)
    }

    /// Returns this objects metadata as [`ObjectMeta`]
    pub fn object_meta(&self, base_url: &Url) -> Result<ObjectMeta> {
        let last_modified = self.prop_stat.prop.last_modified;
        Ok(ObjectMeta {
            location: self.path(base_url)?,
            last_modified,
            size: self.size()?,
            e_tag: self.prop_stat.prop.e_tag.clone(),
            version: None,
        })
    }

    /// Returns true if this is a directory / collection
    pub fn is_dir(&self) -> bool {
        self.prop_stat.prop.resource_type.collection.is_some()
    }
}

#[derive(Deserialize)]
pub struct PropStat {
    prop: Prop,
    status: String,
}

#[derive(Deserialize)]
pub struct Prop {
    #[serde(deserialize_with = "deserialize_rfc1123", rename = "getlastmodified")]
    last_modified: DateTime<Utc>,

    #[serde(rename = "getcontentlength")]
    content_length: Option<usize>,

    #[serde(rename = "resourcetype")]
    resource_type: ResourceType,

    #[serde(rename = "getetag")]
    e_tag: Option<String>,
}

#[derive(Deserialize)]
pub struct ResourceType {
    collection: Option<()>,
}