//! An unofficial Rust client for [the Anthropic/Claude API](https://docs.anthropic.com/claude/reference/getting-started-with-the-api).
//!
//! ## Supported APIs
//! - [Messages](`crate::messages`)
//!     - [x] [Create a Message](https://docs.anthropic.com/claude/reference/messages_post)
//!     - [x] [Streaming Messages](https://docs.anthropic.com/claude/reference/messages-streaming)
//!
//! ## Feature flags
//! - `macros`: Enable the [`attributes::clust_tool`] attribute macro for generating [`messages::ToolDefinition`]
//!   or [`messages::AsyncTool`] from a Rust function.
//!
//! ## Usages
//!
//! ### API key and client
//! First you need to create a new API client: `clust::Client` with your Anthropic API key from environment variable: "ANTHROPIC_API_KEY"
//!
//! ```rust,no_run
//! use clust::Client;
//!
//! let client = Client::from_env().unwrap();
//! ```
//!
//! or specify the API key directly:
//!
//! ```rust
//! use clust::Client;
//! use clust::ApiKey;
//!
//! let client = Client::from_api_key(ApiKey::new("your-api-key"));
//! ```
//!
//! If you want to customize the client, you can use builder pattern by `clust::ClientBuilder`:
//! ```rust
//! use clust::ClientBuilder;
//! use clust::ApiKey;
//! use clust::Version;
//!
//! let client = ClientBuilder::new(ApiKey::new("your-api-key"))
//!     .version(Version::V2023_06_01)
//!     .client(reqwest::ClientBuilder::new().timeout(std::time::Duration::from_secs(10)).build().unwrap())
//!     .build();
//! ```
//!
//! ### Models and max tokens
//! You can specify the model by `clust::messages::ClaudeModel`.
//!
//! ```rust
//! use clust::messages::ClaudeModel;
//! use clust::messages::MessagesRequestBody;
//!
//! let model = ClaudeModel::Claude3Sonnet20240229;
//!
//! let request_body = MessagesRequestBody {
//!     model,
//!     ..Default::default()
//! };
//! ```
//!
//! Because max number of tokens of text generation: `clust::messages::MaxTokens` depends on the model,
//! you need to create `clust::messages::MaxTokens` with the model.
//!
//! ```rust
//! use clust::messages::ClaudeModel;
//! use clust::messages::MaxTokens;
//! use clust::messages::MessagesRequestBody;
//!
//! let model = ClaudeModel::Claude3Sonnet20240229;
//! let max_tokens = MaxTokens::new(1024, model).unwrap();
//!
//! let request_body = MessagesRequestBody {
//!     model,
//!     max_tokens,
//!     ..Default::default()
//! };
//! ```
//!
//! ### Prompt
//! You can specify the system prompt by `clust::messages::SystemPrompt` and there is no "system" role in the message.
//!
//! ```rust
//! use clust::messages::SystemPrompt;
//! use clust::messages::MessagesRequestBody;
//!
//! let system_prompt = SystemPrompt::new("You are an excellent AI assistant.");
//!
//! let request_body = MessagesRequestBody {
//!     system: Some(system_prompt),
//!     ..Default::default()
//! };
//! ```
//!
//! ### Messages and contents
//! Build messages by a vector of `clust::messages::Message`:
//!
//! ```rust
//! use clust::messages::Role;
//! use clust::messages::Content;
//!
//! /// The message.
//! pub struct Message {
//!     /// The role of the message.
//!     pub role: Role,
//!     /// The content of the message.
//!     pub content: Content,
//! }
//! ```
//!
//! You can create each role message as follows:
//!
//! ```rust
//! use clust::messages::Message;
//!
//! let message = Message::user("Hello, Claude!");
//! let message = Message::assistant("Hello, user!");
//! ```
//!
//! and a content: `clust::messages::Content`.
//!
//! ```rust
//! use clust::messages::ContentBlock;
//!
//! /// The content of the message.
//! pub enum Content {
//!     /// The single text content.
//!     SingleText(String),
//!     /// The multiple content blocks.
//!     MultipleBlocks(Vec<ContentBlock>),
//! }
//! ```
//!
//! Multiple blocks is a vector of content block: `clust::messages::ContentBlock`:
//!
//! ```rust
//! use clust::messages::TextContentBlock;
//! use clust::messages::ImageContentBlock;
//!
//! /// The content block of the message.
//! pub enum ContentBlock {
//!     /// The text content block.
//!     Text(TextContentBlock),
//!     /// The image content block.
//!     Image(ImageContentBlock),
//! }
//! ```
//!
//! You can create a content as follows:
//!
//! ```rust
//! use clust::messages::Content;
//! use clust::messages::ContentBlock;
//! use clust::messages::TextContentBlock;
//! use clust::messages::ImageContentBlock;
//! use clust::messages::ImageContentSource;
//! use clust::messages::ImageMediaType;
//!
//! // Single text content
//! let content = Content::SingleText("Hello, Claude!".to_string());
//! // or use `From` trait
//! let content = Content::from("Hello, Claude!");
//!
//! // Multiple content blocks
//! let content = Content::MultipleBlocks(vec![
//!     ContentBlock::Text(TextContentBlock::new("Hello, Claude!")),
//!     ContentBlock::Image(ImageContentBlock::new(ImageContentSource::base64(
//!          ImageMediaType::Png,
//!          "Base64 encoded image data",
//!     ))),
//! ]);
//! // or use `From` trait for `String` or `ImageContentSource`
//! let content = Content::from(vec![
//!     ContentBlock::from("Hello, Claude!"),
//!     ContentBlock::from(ImageContentSource::base64(
//!          ImageMediaType::Png,
//!          "Base64 encoded image data",
//!     )),
//! ]);
//!
//! ```
//!
//! ### Request body
//! The request body is defined by `clust::messages::MessagesRequestBody`.
//!
//! ```rust
//! use clust::messages::MessagesRequestBody;
//! use clust::messages::ClaudeModel;
//! use clust::messages::Message;
//! use clust::messages::MaxTokens;
//! use clust::messages::SystemPrompt;
//!
//! let request_body = MessagesRequestBody {
//!     model: ClaudeModel::Claude3Sonnet20240229,
//!     messages: vec![Message::user("Hello, Claude!")],
//!     max_tokens: MaxTokens::new(1024, ClaudeModel::Claude3Sonnet20240229).unwrap(),
//!     system: Some(SystemPrompt::new("You are an excellent AI assistant.")),
//!     ..Default::default()
//! };
//! ```
//!
//! You can also use the builder pattern with `clust::messages::MessagesRequestBuilder`:
//!
//! ```rust
//! use clust::messages::MessagesRequestBuilder;
//! use clust::messages::ClaudeModel;
//! use clust::messages::Message;
//! use clust::messages::SystemPrompt;
//!
//! let request_body = MessagesRequestBuilder::new_with_max_tokens(
//!     ClaudeModel::Claude3Sonnet20240229,
//!     1024,
//! ).unwrap()
//! .messages(vec![Message::user("Hello, Claude!")])
//! .system(SystemPrompt::new("You are an excellent AI assistant."))
//! .build();
//! ```
//!
//! ### API calling
//! Call the API by `clust::Client::create_a_message` with the request body.
//!
//! ```rust,no_run
//! use clust::Client;
//! use clust::messages::MessagesRequestBody;
//!
//! #[tokio::main]
//! async fn main() -> anyhow::Result<()> {
//!     let client = Client::from_env()?;
//!     let request_body = MessagesRequestBody::default();
//!
//!     // Call the async API.
//!     let response = client
//!         .create_a_message(request_body)
//!         .await?;
//!
//!     // You can extract the text content from `clust::messages::MessagesResponseBody.content.flatten_into_text()`.
//!     println!("Content: {}", response.content.flatten_into_text()?);
//!
//!     Ok(())
//! }
//! ```
//!
//! ### Streaming
//! When you want to stream the response incrementally,
//! you can use `clust::Client::create_a_message_stream` with the stream option: `StreamOption::ReturnStream`.
//!
//! ```rust,no_run
//! use clust::Client;
//! use clust::messages::MessagesRequestBody;
//! use clust::messages::StreamOption;
//!
//! use tokio_stream::StreamExt;
//!
//! #[tokio::main]
//! async fn main() -> anyhow::Result<()> {
//!     let client = Client::from_env()?;
//!     let request_body = MessagesRequestBody {
//!         stream: Some(StreamOption::ReturnStream),
//!         ..Default::default()
//!     };
//!
//!     // Call the async API and get the stream.
//!     let mut stream = client
//!         .create_a_message_stream(request_body)
//!         .await?;
//!
//!     // Poll the stream.
//!     while let Some(chunk) = stream.next().await {
//!          // Handle the chunk.
//!     }
//!
//!     Ok(())
//! }
//! ```
//!
//! ### Tool use
//!
//! Support [tool use](https://docs.anthropic.com/en/docs/build-with-claude/tool-use) for two methods:
//!
//! #### 1. Use `clust_tool` attribute macro for Rust function
//!
//! When you define a tool as Rust function with documentation comment like this:
//!
//! ```rust,no_run
//! /// Get the current weather in a given location
//! ///
//! /// ## Arguments
//! /// - `location` - The city and state, e.g. San Francisco, CA
//! fn get_weather(location: String) -> String {
//!     "15 degrees".to_string() // Dummy response
//! }
//! ```
//!
//! you can use the `clust::clust_macros::clust_tool` attribute macro with `macros` feature flag to generate code:
//!
//! ```rust,no_run
//! /// Get the current weather in a given location
//! ///
//! /// ## Arguments
//! /// - `location` - The city and state, e.g. San Francisco, CA
//! #[clust_tool] // <- Generate `clust::messages::Tool` for this function
//! fn get_weather(location: String) -> String {
//!     "15 degrees".to_string() // Dummy response
//! }
//! ```
//!
//! and create an instance of `clust::messages::Tool` that named by `ClustTool_{function_name}` from the function:
//!
//! ```rust,no_run
//! let tool = ClustTool_get_weather {};
//! ```
//!
//! Get the tool definition from `clust::messages::Tool` for API request:
//!
//! ```rust,no_run
//! let tool_definition = tool.definition();
//! ```
//!
//! and call the tool with tool use got from the API response:
//!
//! ```rust,no_run
//! let tool_result = tool.call(tool_use);
//! ```
//!
//! See also [a tool use example](./examples/tool_use.rs) and [clust_tool](./clust_macros/src/lib.rs) for details.
//!
//! #### 2. Manually implement `clust::messages::Tool` or `clust::messages::AsyncTool`
//!
//! You can manually implement `clust::messages::Tool` or `clust::messages::AsyncTool` for your tool.
//!
//! ## Examples
//!
//! ### Create a message
//! An example of creating a message with the API key loaded from the environment variable: `ANTHROPIC_API_KEY`
//!
//! ```env
//! ANTHROPIC_API_KEY={your-api-key}
//! ```
//!
//! is as follows:
//!
//! ```rust,no_run
//! use clust::messages::ClaudeModel;
//! use clust::messages::MaxTokens;
//! use clust::messages::Message;
//! use clust::messages::MessagesRequestBody;
//! use clust::messages::SystemPrompt;
//! use clust::Client;
//!
//! #[tokio::main]
//! async fn main() -> anyhow::Result<()> {
//!     // 1. Create a new API client with the API key loaded from the environment variable: `ANTHROPIC_API_KEY`.
//!     let client = Client::from_env()?;
//!
//!     // 2. Create a request body.
//!     let model = ClaudeModel::Claude3Sonnet20240229;
//!     let messages = vec![Message::user(
//!         "Where is the capital of France?",
//!     )];
//!     let max_tokens = MaxTokens::new(1024, model)?;
//!     let system_prompt = SystemPrompt::new("You are an excellent AI assistant.");
//!     let request_body = MessagesRequestBody {
//!         model,
//!         messages,
//!         max_tokens,
//!         system: Some(system_prompt),
//!         ..Default::default()
//!     };
//!
//!     // 3. Call the API.
//!     let response = client
//!         .create_a_message(request_body)
//!         .await?;
//!
//!     println!("Result:\n{}", response);
//!
//!     Ok(())
//! }
//! ```
//!
//! ### Streaming messages with `tokio` backend
//! An example of creating a message stream with the API key loaded from the environment variable: `ANTHROPIC_API_KEY`
//!
//! ```env
//! ANTHROPIC_API_KEY={your-api-key}
//! ```
//!
//! with [tokio-stream](https://docs.rs/tokio-stream/latest/tokio_stream/) is as follows:
//!
//! ```rust,no_run
//! use clust::messages::ClaudeModel;
//! use clust::messages::MaxTokens;
//! use clust::messages::Message;
//! use clust::messages::MessagesRequestBody;
//! use clust::messages::SystemPrompt;
//! use clust::messages::StreamOption;
//! use clust::messages::MessageChunk;
//! use clust::Client;
//!
//! use tokio_stream::StreamExt;
//!
//! #[tokio::main]
//! async fn main() -> anyhow::Result<()> {
//!     // 1. Create a new API client with the API key loaded from the environment variable: `ANTHROPIC_API_KEY`.
//!     let client = Client::from_env()?;
//!
//!     // 2. Create a request body with `stream` option.
//!     let model = ClaudeModel::Claude3Sonnet20240229;
//!     let messages = vec![Message::user(
//!         "Where is the capital of France?",
//!     )];
//!     let max_tokens = MaxTokens::new(1024, model)?;
//!     let system_prompt = SystemPrompt::new("You are an excellent AI assistant.");
//!     let request_body = MessagesRequestBody {
//!         model,
//!         messages,
//!         max_tokens,
//!         system: Some(system_prompt),
//!         stream: Some(StreamOption::ReturnStream),
//!         ..Default::default()
//!     };
//!
//!     // 3. Call the streaming API.
//!     let mut stream = client
//!         .create_a_message_stream(request_body)
//!         .await?;
//!
//!     let mut buffer = String::new();
//!
//!     // 4. Poll the stream.
//!     // NOTE: The `futures_util::StreamExt` run on the single thread.
//!     while let Some(chunk) = stream.next().await {
//!         match chunk {
//!             | Ok(chunk) => {
//!                 println!("Chunk:\n{}", chunk);
//!                 match chunk {
//!                     | MessageChunk::ContentBlockDelta(content_block_delta) => {
//!                         // Buffer message delta.
//!                         buffer.push_str(&content_block_delta.delta.text);
//!                     }
//!                     | _ => {}
//!                 }
//!             }
//!             | Err(error) => {
//!                 eprintln!("Chunk error:\n{:?}", error);
//!             }
//!         }
//!     }
//!
//!     println!("Result:\n{}", buffer);
//!
//!     Ok(())
//! }
//! ```
//!
//! ### Create a message with vision
//!
//! See [an example with vision](./examples/create_a_message_with_vision.rs).
//!
//! ### Conversation
//!
//! See [a conversation example](./examples/conversation.rs).
//!
//! ### Tool use
//!
//! See [a tool use example](./examples/tool_use.rs).
//!
//! ### Other examples
//!
//! See also the [examples](./examples) directory for more examples.

mod api_key;
mod beta;
mod client;
mod error;
mod version;

pub(crate) mod macros;

pub mod messages;

#[cfg(feature = "macros")]
pub mod attributes;

pub use api_key::ApiKey;
pub use beta::Beta;
pub use client::Client;
pub use client::ClientBuilder;
pub use error::ApiError;
pub use error::ApiErrorBody;
pub use error::ApiErrorResponse;
pub use error::ApiErrorType;
pub use error::ClientError;
pub use error::ValidationError;
pub use version::Version;

pub use futures_core;
pub use reqwest;
pub use serde_json;

#[cfg(feature = "macros")]
pub use clust_macros;