//! Builder pattern for SupervisorClient to ensure proper configuration
//!
//! This module provides a type-safe builder that guarantees a client cannot be
//! created without a secret, preventing authentication issues.

#[cfg(target_arch = "wasm32")]
use crate::wasm::WasmSupervisorClient;

#[cfg(not(target_arch = "wasm32"))]
use crate::{SupervisorClient, HttpTransport, ClientResult, ClientError};
#[cfg(not(target_arch = "wasm32"))]
use jsonrpsee::http_client::HttpClientBuilder;
#[cfg(not(target_arch = "wasm32"))]
use http::{HeaderMap, HeaderName, HeaderValue};

/// Builder for WasmSupervisorClient that enforces secret requirement
#[cfg(target_arch = "wasm32")]
#[derive(Clone)]
pub struct WasmSupervisorClientBuilder {
    server_url: Option<String>,
    secret: Option<String>,
}

#[cfg(target_arch = "wasm32")]
impl WasmSupervisorClientBuilder {
    /// Create a new builder
    pub fn new() -> Self {
        Self {
            server_url: None,
            secret: None,
        }
    }

    /// Set the server URL
    pub fn server_url(mut self, url: impl Into<String>) -> Self {
        self.server_url = Some(url.into());
        self
    }

    /// Set the authentication secret (required)
    pub fn secret(mut self, secret: impl Into<String>) -> Self {
        self.secret = Some(secret.into());
        self
    }

    /// Build the client
    /// 
    /// Returns Err if server_url or secret is not set
    pub fn build(self) -> Result<WasmSupervisorClient, String> {
        let server_url = self.server_url.ok_or("Server URL is required")?;
        let secret = self.secret.ok_or("Secret is required for authenticated client")?;
        
        if secret.is_empty() {
            return Err("Secret cannot be empty".to_string());
        }
        
        Ok(WasmSupervisorClient::new(server_url, secret))
    }
}

#[cfg(target_arch = "wasm32")]
impl Default for WasmSupervisorClientBuilder {
    fn default() -> Self {
        Self::new()
    }
}

/// Builder for SupervisorClient (HTTP transport)
#[cfg(not(target_arch = "wasm32"))]
#[derive(Debug, Clone)]
pub struct SupervisorClientBuilder {
    url: Option<String>,
    secret: Option<String>,
    timeout: Option<std::time::Duration>,
}

#[cfg(not(target_arch = "wasm32"))]
impl SupervisorClientBuilder {
    /// Create a new builder
    pub fn new() -> Self {
        Self {
            url: None,
            secret: None,
            timeout: Some(std::time::Duration::from_secs(30)),
        }
    }
    
    /// Set the server URL
    pub fn url(mut self, url: impl Into<String>) -> Self {
        self.url = Some(url.into());
        self
    }
    
    /// Set the authentication secret
    pub fn secret(mut self, secret: impl Into<String>) -> Self {
        self.secret = Some(secret.into());
        self
    }
    
    /// Set the request timeout (default: 30 seconds)
    pub fn timeout(mut self, timeout: std::time::Duration) -> Self {
        self.timeout = Some(timeout);
        self
    }
    
    /// Build the SupervisorClient with HTTP transport
    pub fn build(self) -> ClientResult<SupervisorClient<HttpTransport>> {
        let server_url = self.url
            .ok_or_else(|| ClientError::Http("URL is required".to_string()))?;
        let secret = self.secret
            .ok_or_else(|| ClientError::Http("Secret is required".to_string()))?;
        
        // Create headers with Authorization bearer token
        let mut headers = HeaderMap::new();
        let auth_value = format!("Bearer {}", secret);
        headers.insert(
            HeaderName::from_static("authorization"),
            HeaderValue::from_str(&auth_value)
                .map_err(|e| ClientError::Http(format!("Invalid auth header: {}", e)))?
        );
        
        let client = HttpClientBuilder::default()
            .request_timeout(self.timeout.unwrap_or(std::time::Duration::from_secs(30)))
            .set_headers(headers)
            .build(&server_url)
            .map_err(|e| ClientError::Http(e.to_string()))?;
        
        let transport = HttpTransport { client };
        
        Ok(SupervisorClient {
            transport,
            secret,
        })
    }
}

#[cfg(not(target_arch = "wasm32"))]
impl Default for SupervisorClientBuilder {
    fn default() -> Self {
        Self::new()
    }
}

#[cfg(all(test, target_arch = "wasm32"))]
mod tests {
    use super::*;

    #[test]
    fn test_builder_requires_all_fields() {
        let builder = WasmSupervisorClientBuilder::new();
        assert!(builder.build().is_err());

        let builder = WasmSupervisorClientBuilder::new()
            .server_url("http://localhost:3030");
        assert!(builder.build().is_err());

        let builder = WasmSupervisorClientBuilder::new()
            .secret("test-secret");
        assert!(builder.build().is_err());
    }

    #[test]
    fn test_builder_success() {
        let builder = WasmSupervisorClientBuilder::new()
            .server_url("http://localhost:3030")
            .secret("test-secret");
        assert!(builder.build().is_ok());
    }

    #[test]
    fn test_build_error_messages() {
        let result = WasmSupervisorClientBuilder::new().build();
        assert!(result.is_err());
        assert_eq!(result.unwrap_err(), "Server URL is required");

        let result = WasmSupervisorClientBuilder::new()
            .server_url("http://localhost:3030")
            .build();
        assert!(result.is_err());
        assert_eq!(result.unwrap_err(), "Secret is required for authenticated client");
        
        let result = WasmSupervisorClientBuilder::new()
            .server_url("http://localhost:3030")
            .secret("")
            .build();
        assert!(result.is_err());
        assert_eq!(result.unwrap_err(), "Secret cannot be empty");
    }
}