//! # Elefren: API Wrapper around the Mastodon API.
//!
//! Most of the api is documented on [Mastodon's website](https://docs.joinmastodon.org/api/)
//!
//! ```no_run
//! # extern crate elefren;
//! # fn main() {
//! #    try().unwrap();
//! # }
//! # fn try() -> elefren::Result<()> {
//! use elefren::{helpers::cli, prelude::*};
//!
//! let registration = Registration::new("https://mastodon.social")
//!     .client_name("elefren_test")
//!     .build()?;
//! let mastodon = cli::authenticate(registration)?;
//!
//! println!(
//!     "{:?}",
//!     mastodon
//!         .get_home_timeline()?
//!         .items_iter()
//!         .take(100)
//!         .collect::<Vec<_>>()
//! );
//! # Ok(())
//! # }
//! ```
//!
//! Elefren also supports Mastodon's Streaming API:
//!
//! # Example
//!
//! ```no_run
//! # extern crate elefren;
//! # use elefren::prelude::*;
//! # use std::error::Error;
//! use elefren::entities::event::Event;
//! # fn main() -> Result<(), Box<Error>> {
//! # let data = Data {
//! #   base: "".into(),
//! #   client_id: "".into(),
//! #   client_secret: "".into(),
//! #   redirect: "".into(),
//! #   token: "".into(),
//! # };
//! let client = Mastodon::from(data);
//! for event in client.streaming_user()? {
//!     match event {
//!         Event::Update(ref status) => { /* .. */ },
//!         Event::Notification(ref notification) => { /* .. */ },
//!         Event::Delete(ref id) => { /* .. */ },
//!         Event::FiltersChanged => { /* .. */ },
//!     }
//! }
//! # Ok(())
//! # }
//! ```

#![deny(
    missing_docs,
    warnings,
    missing_debug_implementations,
    missing_copy_implementations,
    trivial_casts,
    trivial_numeric_casts,
    unsafe_code,
    unstable_features,
    unused_import_braces,
    unused_qualifications
)]
#![allow(intra_doc_link_resolution_failure)]

#[macro_use]
extern crate log;
#[macro_use]
extern crate serde_derive;
#[macro_use]
extern crate doc_comment;
extern crate hyper_old_types;
extern crate isolang;
#[macro_use]
extern crate serde_json;
extern crate chrono;
extern crate reqwest;
extern crate serde;
extern crate serde_qs;
extern crate serde_urlencoded;
extern crate tap_reader;
extern crate try_from;
extern crate url;

#[cfg(feature = "env")]
extern crate envy;

#[cfg(feature = "toml")]
extern crate toml as tomlcrate;

#[cfg(test)]
extern crate tempfile;

#[cfg(test)]
#[cfg_attr(all(test, any(feature = "toml", feature = "json")), macro_use)]
extern crate indoc;

use std::{
    borrow::Cow,
    io::{BufRead, BufReader},
    ops,
};

use reqwest::{Client, RequestBuilder, Response};
use tap_reader::Tap;

use entities::prelude::*;
use http_send::{HttpSend, HttpSender};
use page::Page;

pub use data::Data;
pub use errors::{ApiError, Error, Result};
pub use isolang::Language;
pub use mastodon_client::{MastodonClient, MastodonUnauthenticated};
pub use registration::Registration;
pub use requests::{
    AddFilterRequest,
    AddPushRequest,
    StatusesRequest,
    UpdateCredsRequest,
    UpdatePushRequest,
};
pub use status_builder::{NewStatus, StatusBuilder};

/// Registering your App
pub mod apps;
/// Contains the struct that holds the client auth data
pub mod data;
/// Entities returned from the API
pub mod entities;
/// Errors
pub mod errors;
/// Collection of helpers for serializing/deserializing `Data` objects
pub mod helpers;
/// Contains trait for converting `reqwest::Request`s to `reqwest::Response`s
pub mod http_send;
mod mastodon_client;
/// Handling multiple pages of entities.
pub mod page;
/// Registering your app.
pub mod registration;
/// Requests
pub mod requests;
/// OAuth Scopes
pub mod scopes;
/// Constructing a status
pub mod status_builder;
#[macro_use]
mod macros;
/// Automatically import the things you need
pub mod prelude {
    pub use scopes::Scopes;
    pub use Data;
    pub use Mastodon;
    pub use MastodonClient;
    pub use NewStatus;
    pub use Registration;
    pub use StatusBuilder;
    pub use StatusesRequest;
}

/// Your mastodon application client, handles all requests to and from Mastodon.
#[derive(Clone, Debug)]
pub struct Mastodon<H: HttpSend = HttpSender> {
    client: Client,
    http_sender: H,
    /// Raw data about your mastodon instance.
    pub data: Data,
}

impl<H: HttpSend> Mastodon<H> {
    methods![get, post, delete,];

    fn route(&self, url: &str) -> String {
        format!("{}{}", self.base, url)
    }

    pub(crate) fn send(&self, req: RequestBuilder) -> Result<Response> {
        Ok(self
            .http_sender
            .send(&self.client, req.bearer_auth(&self.token))?)
    }
}

impl From<Data> for Mastodon<HttpSender> {
    /// Creates a mastodon instance from the data struct.
    fn from(data: Data) -> Mastodon<HttpSender> {
        let mut builder = MastodonBuilder::new(HttpSender);
        builder.data(data);
        builder
            .build()
            .expect("We know `data` is present, so this should be fine")
    }
}

impl<H: HttpSend> MastodonClient<H> for Mastodon<H> {
    type Stream = EventReader<BufReader<Response>>;

    paged_routes! {
        (get) favourites: "favourites" => Status,
        (get) blocks: "blocks" => Account,
        (get) domain_blocks: "domain_blocks" => String,
        (get) follow_requests: "follow_requests" => Account,
        (get) get_home_timeline: "timelines/home" => Status,
        (get) get_emojis: "custom_emojis" => Emoji,
        (get) mutes: "mutes" => Account,
        (get) notifications: "notifications" => Notification,
        (get) reports: "reports" => Report,
        (get (q: &'a str, #[serde(skip_serializing_if = "Option::is_none")] limit: Option<u64>, following: bool,)) search_accounts: "accounts/search" => Account,
        (get) get_endorsements: "endorsements" => Account,
    }

    paged_routes_with_id! {
        (get) followers: "accounts/{}/followers" => Account,
        (get) following: "accounts/{}/following" => Account,
        (get) reblogged_by: "statuses/{}/reblogged_by" => Account,
        (get) favourited_by: "statuses/{}/favourited_by" => Account,
    }

    route! {
        (delete (domain: String,)) unblock_domain: "domain_blocks" => Empty,
        (get) instance: "instance" => Instance,
        (get) verify_credentials: "accounts/verify_credentials" => Account,
        (post (account_id: &str, status_ids: Vec<&str>, comment: String,)) report: "reports" => Report,
        (post (domain: String,)) block_domain: "domain_blocks" => Empty,
        (post (id: &str,)) authorize_follow_request: "accounts/follow_requests/authorize" => Empty,
        (post (id: &str,)) reject_follow_request: "accounts/follow_requests/reject" => Empty,
        (get  (q: &'a str, resolve: bool,)) search: "search" => SearchResult,
        (get  (local: bool,)) get_public_timeline: "timelines/public" => Vec<Status>,
        (post (uri: Cow<'static, str>,)) follows: "follows" => Account,
        (post multipart (file: Cow<'static, str>,)) media: "media" => Attachment,
        (post) clear_notifications: "notifications/clear" => Empty,
        (post (id: &str,)) dismiss_notification: "notifications/dismiss" => Empty,
        (get) get_push_subscription: "push/subscription" => Subscription,
        (delete) delete_push_subscription: "push/subscription" => Empty,
        (get) get_filters: "filters" => Vec<Filter>,
        (get) get_follow_suggestions: "suggestions" => Vec<Account>,
    }

    route_v2! {
        (get (q: &'a str, resolve: bool,)) search_v2: "search" => SearchResultV2,
    }

    route_id! {
        (get) get_account: "accounts/{}" => Account,
        (post) follow: "accounts/{}/follow" => Relationship,
        (post) unfollow: "accounts/{}/unfollow" => Relationship,
        (post) block: "accounts/{}/block" => Relationship,
        (post) unblock: "accounts/{}/unblock" => Relationship,
        (get) mute: "accounts/{}/mute" => Relationship,
        (get) unmute: "accounts/{}/unmute" => Relationship,
        (get) get_notification: "notifications/{}" => Notification,
        (get) get_status: "statuses/{}" => Status,
        (get) get_context: "statuses/{}/context" => Context,
        (get) get_card: "statuses/{}/card" => Card,
        (post) reblog: "statuses/{}/reblog" => Status,
        (post) unreblog: "statuses/{}/unreblog" => Status,
        (post) favourite: "statuses/{}/favourite" => Status,
        (post) unfavourite: "statuses/{}/unfavourite" => Status,
        (delete) delete_status: "statuses/{}" => Empty,
        (get) get_filter: "filters/{}" => Filter,
        (delete) delete_filter: "filters/{}" => Empty,
        (delete) delete_from_suggestions: "suggestions/{}" => Empty,
        (post) endorse_user: "accounts/{}/pin" => Relationship,
        (post) unendorse_user: "accounts/{}/unpin" => Relationship,
    }

    fn add_filter(&self, request: &mut AddFilterRequest) -> Result<Filter> {
        let url = self.route("/api/v1/filters");
        let response = self.send(self.client.post(&url).json(&request))?;

        let status = response.status();

        if status.is_client_error() {
            return Err(Error::Client(status.clone()));
        } else if status.is_server_error() {
            return Err(Error::Server(status.clone()));
        }

        deserialise(response)
    }

    /// PUT /api/v1/filters/:id
    fn update_filter(&self, id: &str, request: &mut AddFilterRequest) -> Result<Filter> {
        let url = self.route(&format!("/api/v1/filters/{}", id));
        let response = self.send(self.client.put(&url).json(&request))?;

        let status = response.status();

        if status.is_client_error() {
            return Err(Error::Client(status.clone()));
        } else if status.is_server_error() {
            return Err(Error::Server(status.clone()));
        }

        deserialise(response)
    }

    fn update_credentials(&self, builder: &mut UpdateCredsRequest) -> Result<Account> {
        let changes = builder.build()?;
        let url = self.route("/api/v1/accounts/update_credentials");
        let response = self.send(self.client.patch(&url).json(&changes))?;

        let status = response.status();

        if status.is_client_error() {
            return Err(Error::Client(status.clone()));
        } else if status.is_server_error() {
            return Err(Error::Server(status.clone()));
        }

        deserialise(response)
    }

    /// Post a new status to the account.
    fn new_status(&self, status: NewStatus) -> Result<Status> {
        let response = self.send(
            self.client
                .post(&self.route("/api/v1/statuses"))
                .json(&status),
        )?;

        deserialise(response)
    }

    /// Get timeline filtered by a hashtag(eg. `#coffee`) either locally or
    /// federated.
    fn get_tagged_timeline(&self, hashtag: String, local: bool) -> Result<Vec<Status>> {
        let base = "/api/v1/timelines/tag/";
        let url = if local {
            self.route(&format!("{}{}?local=1", base, hashtag))
        } else {
            self.route(&format!("{}{}", base, hashtag))
        };

        self.get(url)
    }

    /// Get statuses of a single account by id. Optionally only with pictures
    /// and or excluding replies.
    ///
    /// # Example
    ///
    /// ```no_run
    /// # extern crate elefren;
    /// # use elefren::prelude::*;
    /// # use std::error::Error;
    /// # fn main() -> Result<(), Box<Error>> {
    /// # let data = Data {
    /// #   base: "".into(),
    /// #   client_id: "".into(),
    /// #   client_secret: "".into(),
    /// #   redirect: "".into(),
    /// #   token: "".into(),
    /// # };
    /// let client = Mastodon::from(data);
    /// let statuses = client.statuses("user-id", None)?;
    /// # Ok(())
    /// # }
    /// ```
    ///
    /// ```no_run
    /// # extern crate elefren;
    /// # use elefren::prelude::*;
    /// # use std::error::Error;
    /// # fn main() -> Result<(), Box<Error>> {
    /// # let data = Data {
    /// #   base: "".into(),
    /// #   client_id: "".into(),
    /// #   client_secret: "".into(),
    /// #   redirect: "".into(),
    /// #   token: "".into(),
    /// # };
    /// let client = Mastodon::from(data);
    /// let mut request = StatusesRequest::new();
    /// request.only_media();
    /// let statuses = client.statuses("user-id", request)?;
    /// # Ok(())
    /// # }
    /// ```
    fn statuses<'a, 'b: 'a, S>(&'b self, id: &'b str, request: S) -> Result<Page<Status, H>>
    where
        S: Into<Option<StatusesRequest<'a>>>,
    {
        let mut url = format!("{}/api/v1/accounts/{}/statuses", self.base, id);

        if let Some(request) = request.into() {
            url = format!("{}{}", url, request.to_querystring()?);
        }

        let response = self.send(self.client.get(&url))?;

        Page::new(self, response)
    }

    /// Returns the client account's relationship to a list of other accounts.
    /// Such as whether they follow them or vice versa.
    fn relationships(&self, ids: &[&str]) -> Result<Page<Relationship, H>> {
        let mut url = self.route("/api/v1/accounts/relationships?");

        if ids.len() == 1 {
            url += "id=";
            url += &ids[0];
        } else {
            for id in ids {
                url += "id[]=";
                url += &id;
                url += "&";
            }
            url.pop();
        }

        let response = self.send(self.client.get(&url))?;

        Page::new(self, response)
    }

    /// Add a push notifications subscription
    fn add_push_subscription(&self, request: &AddPushRequest) -> Result<Subscription> {
        let request = request.build()?;
        let response = self.send(
            self.client
                .post(&self.route("/api/v1/push/subscription"))
                .json(&request),
        )?;

        deserialise(response)
    }

    /// Update the `data` portion of the push subscription associated with this
    /// access token
    fn update_push_data(&self, request: &UpdatePushRequest) -> Result<Subscription> {
        let request = request.build();
        let response = self.send(
            self.client
                .put(&self.route("/api/v1/push/subscription"))
                .json(&request),
        )?;

        deserialise(response)
    }

    /// Get all accounts that follow the authenticated user
    fn follows_me(&self) -> Result<Page<Account, H>> {
        let me = self.verify_credentials()?;
        Ok(self.followers(&me.id)?)
    }

    /// Get all accounts that the authenticated user follows
    fn followed_by_me(&self) -> Result<Page<Account, H>> {
        let me = self.verify_credentials()?;
        Ok(self.following(&me.id)?)
    }

    /// returns events that are relevant to the authorized user, i.e. home
    /// timeline & notifications
    ///
    /// # Example
    ///
    /// ```no_run
    /// # extern crate elefren;
    /// # use elefren::prelude::*;
    /// # use std::error::Error;
    /// use elefren::entities::event::Event;
    /// # fn main() -> Result<(), Box<Error>> {
    /// # let data = Data {
    /// #   base: "".into(),
    /// #   client_id: "".into(),
    /// #   client_secret: "".into(),
    /// #   redirect: "".into(),
    /// #   token: "".into(),
    /// # };
    /// let client = Mastodon::from(data);
    /// for event in client.streaming_user()? {
    ///     match event {
    ///         Event::Update(ref status) => { /* .. */ },
    ///         Event::Notification(ref notification) => { /* .. */ },
    ///         Event::Delete(ref id) => { /* .. */ },
    ///         Event::FiltersChanged => { /* .. */ },
    ///     }
    /// }
    /// # Ok(())
    /// # }
    /// ```
    fn streaming_user(&self) -> Result<Self::Stream> {
        let response = self.send(self.client.get(&self.route("/api/v1/streaming/user")))?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// returns all public statuses
    fn streaming_public(&self) -> Result<Self::Stream> {
        let response = self.send(self.client.get(&self.route("/api/v1/streaming/public")))?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// Returns all local statuses
    fn streaming_local(&self) -> Result<Self::Stream> {
        let response = self.send(
            self.client
                .get(&self.route("/api/v1/streaming/public/local")),
        )?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// Returns all public statuses for a particular hashtag
    fn streaming_public_hashtag(&self, hashtag: &str) -> Result<Self::Stream> {
        let response = self.send(
            self.client
                .get(&self.route(&format!("/api/v1/streaming/hashtag?tag={}", hashtag))),
        )?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// Returns all local statuses for a particular hashtag
    fn streaming_local_hashtag(&self, hashtag: &str) -> Result<Self::Stream> {
        let response = self.send(
            self.client
                .get(&self.route(&format!("/api/v1/streaming/hashtag/local?tag={}", hashtag))),
        )?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// Returns statuses for a list
    fn streaming_list(&self, list_id: &str) -> Result<Self::Stream> {
        let response = self.send(
            self.client
                .get(&self.route(&format!("/api/v1/streaming/list?list={}", list_id))),
        )?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }

    /// Returns all direct messages
    fn streaming_direct(&self) -> Result<Self::Stream> {
        let response = self.send(self.client.get(&self.route("/api/v1/streaming/direct")))?;
        let reader = BufReader::new(response);
        Ok(EventReader(reader))
    }
}

#[derive(Debug)]
/// Iterator that produces events from a mastodon streaming API event stream
pub struct EventReader<R: BufRead>(R);
impl<R: BufRead> Iterator for EventReader<R> {
    type Item = Event;

    fn next(&mut self) -> Option<Self::Item> {
        let mut lines = Vec::new();
        let mut tmp = String::new();
        loop {
            if let Ok(..) = self.0.read_line(&mut tmp) {
                let line = tmp.trim().to_string();
                tmp.clear();
                if line.starts_with(":") {
                    continue;
                }
                if line.is_empty() && !lines.is_empty() {
                    if let Ok(event) = self.make_event(&lines) {
                        lines.clear();
                        return Some(event);
                    } else {
                        continue;
                    }
                }
                lines.push(line);
            }
        }
    }
}

impl<R: BufRead> EventReader<R> {
    fn make_event(&self, lines: &[String]) -> Result<Event> {
        let event = lines
            .iter()
            .find(|line| line.starts_with("event:"))
            .ok_or_else(|| Error::Other("No `event:` line".to_string()))?;
        let event = event[6..].trim();
        let data = lines.iter().find(|line| line.starts_with("data:"));
        Ok(match event {
            "notification" => {
                let data = data.ok_or_else(|| {
                    Error::Other("Missing `data` line for notification".to_string())
                })?;
                let data = data[5..].trim();
                let notification = serde_json::from_str::<Notification>(&data)?;
                Event::Notification(notification)
            },
            "update" => {
                let data =
                    data.ok_or_else(|| Error::Other("Missing `data` line for update".to_string()))?;
                let data = data[5..].trim();
                let status = serde_json::from_str::<Status>(&data)?;
                Event::Update(status)
            },
            "delete" => {
                let data =
                    data.ok_or_else(|| Error::Other("Missing `data` line for delete".to_string()))?;
                let data = data[5..].trim().to_string();
                Event::Delete(data)
            },
            "filters_changed" => Event::FiltersChanged,
            _ => return Err(Error::Other(format!("Unknown event `{}`", event))),
        })
    }
}

impl<H: HttpSend> ops::Deref for Mastodon<H> {
    type Target = Data;

    fn deref(&self) -> &Self::Target {
        &self.data
    }
}

struct MastodonBuilder<H: HttpSend> {
    client: Option<Client>,
    http_sender: H,
    data: Option<Data>,
}

impl<H: HttpSend> MastodonBuilder<H> {
    pub fn new(sender: H) -> Self {
        MastodonBuilder {
            http_sender: sender,
            client: None,
            data: None,
        }
    }

    pub fn client(&mut self, client: Client) -> &mut Self {
        self.client = Some(client);
        self
    }

    pub fn data(&mut self, data: Data) -> &mut Self {
        self.data = Some(data);
        self
    }

    pub fn build(self) -> Result<Mastodon<H>> {
        Ok(if let Some(data) = self.data {
            Mastodon {
                client: self.client.unwrap_or_else(|| Client::new()),
                http_sender: self.http_sender,
                data,
            }
        } else {
            return Err(Error::MissingField("missing field 'data'"));
        })
    }
}

/// Client that can make unauthenticated calls to a mastodon instance
#[derive(Clone, Debug)]
pub struct MastodonUnauth<H: HttpSend = HttpSender> {
    client: Client,
    http_sender: H,
    base: url::Url,
}

impl MastodonUnauth<HttpSender> {
    /// Create a new unauthenticated client
    pub fn new(base: &str) -> Result<MastodonUnauth<HttpSender>> {
        let base = if base.starts_with("https://") {
            base.to_string()
        } else {
            format!("https://{}", base)
        };
        Ok(MastodonUnauth {
            client: Client::new(),
            http_sender: HttpSender,
            base: url::Url::parse(&base)?,
        })
    }
}

impl<H: HttpSend> MastodonUnauth<H> {
    fn route(&self, url: &str) -> Result<url::Url> {
        Ok(self.base.join(url)?)
    }

    fn send(&self, req: RequestBuilder) -> Result<Response> {
        Ok(self.http_sender.send(&self.client, req)?)
    }
}

impl<H: HttpSend> MastodonUnauthenticated<H> for MastodonUnauth<H> {
    /// GET /api/v1/statuses/:id
    fn get_status(&self, id: &str) -> Result<Status> {
        let route = self.route("/api/v1/statuses")?;
        let route = route.join(id)?;
        let response = self.send(self.client.get(route))?;
        deserialise(response)
    }

    /// GET /api/v1/statuses/:id/context
    fn get_context(&self, id: &str) -> Result<Context> {
        let route = self.route("/api/v1/statuses")?;
        let route = route.join(id)?;
        let route = route.join("context")?;
        let response = self.send(self.client.get(route))?;
        deserialise(response)
    }

    /// GET /api/v1/statuses/:id/card
    fn get_card(&self, id: &str) -> Result<Card> {
        let route = self.route("/api/v1/statuses")?;
        let route = route.join(id)?;
        let route = route.join("card")?;
        let response = self.send(self.client.get(route))?;
        deserialise(response)
    }
}

// Convert the HTTP response body from JSON. Pass up deserialization errors
// transparently.
fn deserialise<T: for<'de> serde::Deserialize<'de>>(response: Response) -> Result<T> {
    let mut reader = Tap::new(response);

    match serde_json::from_reader(&mut reader) {
        Ok(t) => {
            debug!("{}", String::from_utf8_lossy(&reader.bytes));
            Ok(t)
        },
        // If deserializing into the desired type fails try again to
        // see if this is an error response.
        Err(e) => {
            error!("{}", String::from_utf8_lossy(&reader.bytes));
            if let Ok(error) = serde_json::from_slice(&reader.bytes) {
                return Err(Error::Api(error));
            }
            Err(e.into())
        },
    }
}