use crate::core::LlmClientTrait;
use crate::types::WorkerError;
use worker_types::{DynamicToolDefinition, LlmProvider, Message, Role, StreamEvent, ToolCall};
use crate::config::UrlConfig;
use futures_util::{Stream, StreamExt};
use reqwest::Client;
use serde::{Deserialize, Serialize};
use serde_json::Value;

#[derive(Debug, Serialize)]
pub(crate) struct XAIRequest {
    pub model: String,
    pub messages: Vec<XAIMessage>,
    #[serde(skip_serializing_if = "std::ops::Not::not")]
    pub stream: bool,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub tools: Option<Vec<XAITool>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub max_tokens: Option<u32>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub temperature: Option<f32>,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct XAIMessage {
    pub role: String,
    pub content: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub tool_calls: Option<Vec<XAIToolCall>>,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct XAIToolCall {
    pub id: String,
    #[serde(rename = "type")]
    pub call_type: String,
    pub function: XAIFunction,
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct XAIFunction {
    pub name: String,
    pub arguments: String,
}

#[derive(Debug, Serialize, Clone)]
pub struct XAITool {
    #[serde(rename = "type")]
    pub tool_type: String,
    pub function: XAIFunctionDef,
}

#[derive(Debug, Serialize, Clone)]
pub struct XAIFunctionDef {
    pub name: String,
    pub description: String,
    pub parameters: Value,
}

#[derive(Debug, Deserialize)]
pub(crate) struct XAIResponse {
    pub choices: Vec<XAIChoice>,
}

#[derive(Debug, Deserialize)]
pub struct XAIChoice {
    pub message: XAIMessage,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub delta: Option<XAIDelta>,
}

#[derive(Debug, Deserialize)]
pub struct XAIDelta {
    pub content: Option<String>,
    pub tool_calls: Option<Vec<XAIToolCall>>,
}

#[derive(Debug, Deserialize)]
pub struct XAIModel {
    pub id: String,
    pub object: String,
    pub created: i64,
    pub owned_by: String,
}

#[derive(Debug, Deserialize)]
pub struct XAIModelsResponse {
    pub object: String,
    pub data: Vec<XAIModel>,
}

pub struct XAIClient {
    api_key: String,
    model: String,
}

impl XAIClient {
    pub fn new(api_key: &str, model: &str) -> Self {
        Self {
            api_key: api_key.to_string(),
            model: model.to_string(),
        }
    }

    pub fn get_model_name(&self) -> String {
        self.model.clone()
    }
}

use async_stream::stream;

impl XAIClient {
    pub async fn chat_stream<'a>(
        &'a self,
        messages: Vec<Message>,
        tools: Option<&[crate::types::DynamicToolDefinition]>,
        llm_debug: Option<crate::types::LlmDebug>,
    ) -> Result<
        Box<dyn Stream<Item = Result<StreamEvent, WorkerError>> + Unpin + Send + 'a>,
        WorkerError,
    > {
        let client = Client::new();
        let url = UrlConfig::get_completion_url("xai");

        let xai_messages: Vec<XAIMessage> = messages
            .into_iter()
            .map(|msg| XAIMessage {
                role: match msg.role {
                    Role::User => "user".to_string(),
                    Role::Model => "assistant".to_string(),
                    Role::System => "system".to_string(),
                    Role::Tool => "tool".to_string(),
                },
                content: msg.content,
                tool_calls: None,
            })
            .collect();

        let xai_tools = tools.map(|tools| {
            tools
                .iter()
                .map(|tool| XAITool {
                    tool_type: "function".to_string(),
                    function: XAIFunctionDef {
                        name: tool.name.clone(),
                        description: tool.description.clone(),
                        parameters: tool.parameters_schema.clone(),
                    },
                })
                .collect()
        });

        let request = XAIRequest {
            model: self.model.clone(),
            messages: xai_messages,
            stream: true,
            tools: xai_tools,
            max_tokens: None,
            temperature: None,
        };

        let response = client
            .post(url)
            .header("Content-Type", "application/json")
            .header("Authorization", format!("Bearer {}", self.api_key))
            .json(&request)
            .send()
            .await
            .map_err(|e| {
                WorkerError::from_api_error(e.to_string(), &crate::types::LlmProvider::XAI)
            })?;

        if !response.status().is_success() {
            let status = response.status();
            let error_body = response.text().await.unwrap_or_default();
            return Err(WorkerError::from_api_error(
                format!("xAI API error: {} - {}", status, error_body),
                &crate::types::LlmProvider::XAI,
            ));
        }

        let stream = stream! {
            if let Some(ref debug) = llm_debug {
                if let Some(debug_event) = debug.debug_request(&self.model, "xAI", &serde_json::to_value(&request).unwrap_or_default()) {
                    yield Ok(debug_event);
                }
            }

            let mut stream = response.bytes_stream();
            let mut buffer = String::new();

            while let Some(chunk) = stream.next().await {
                match chunk {
                    Ok(bytes) => {
                        let chunk_str = String::from_utf8_lossy(&bytes);
                        buffer.push_str(&chunk_str);

                        while let Some(line_end) = buffer.find('\n') {
                            let line = buffer[..line_end].to_string();
                            buffer = buffer[line_end + 1..].to_string();

                            if line.starts_with("data: ") {
                                let data = &line[6..];
                                if data == "[DONE]" {
                                    yield Ok(StreamEvent::Completion(Message::new(
                                        Role::Model,
                                        "".to_string(),
                                    )));
                                    break;
                                }

                                match serde_json::from_str::<Value>(data) {
                                    Ok(json_data) => {
                                        if let Some(ref debug) = llm_debug {
                                            if let Some(debug_event) = debug.debug_response(&self.model, "xAI", &json_data) {
                                                yield Ok(debug_event);
                                            }
                                        }
                                        if let Some(choices) = json_data.get("choices").and_then(|c| c.as_array()) {
                                            for choice in choices {
                                                if let Some(delta) = choice.get("delta") {
                                                    if let Some(content) = delta.get("content").and_then(|c| c.as_str()) {
                                                        yield Ok(StreamEvent::Chunk(content.to_string()));
                                                    }

                                                    if let Some(tool_calls) = delta.get("tool_calls").and_then(|tc| tc.as_array()) {
                                                        for tool_call in tool_calls {
                                                            if let Some(function) = tool_call.get("function") {
                                                                if let (Some(name), Some(arguments)) = (
                                                                    function.get("name").and_then(|n| n.as_str()),
                                                                    function.get("arguments").and_then(|a| a.as_str())
                                                                ) {
                                                                    let tool_call = ToolCall {
                                                                        name: name.to_string(),
                                                                        arguments: arguments.to_string(),
                                                                    };
                                                                    yield Ok(StreamEvent::ToolCall(tool_call));
                                                                }
                                                            }
                                                        }
                                                    }
                                                }
                                            }
                                        }
                                    }
                                    Err(e) => {
                                        tracing::warn!("Failed to parse xAI stream response: {}", e);
                                    }
                                }
                            }
                        }
                    }
                    Err(e) => {
                        yield Err(WorkerError::from_api_error(e.to_string(), &crate::types::LlmProvider::XAI));
                        break;
                    }
                }
            }
        };

        Ok(Box::new(Box::pin(stream)))
    }

    pub async fn get_model_details(
        &self,
        model_id: &str,
    ) -> Result<crate::types::ModelInfo, WorkerError> {
        let client = Client::new();
        let url = UrlConfig::get_model_url("xai", model_id);

        let response = client
            .get(&url)
            .header("Authorization", format!("Bearer {}", self.api_key))
            .send()
            .await
            .map_err(|e| {
                WorkerError::from_api_error(e.to_string(), &crate::types::LlmProvider::XAI)
            })?;

        if !response.status().is_success() {
            return Err(WorkerError::from_api_error(
                format!(
                    "xAI model details request failed with status: {}",
                    response.status()
                ),
                &crate::types::LlmProvider::XAI,
            ));
        }

        let model_data: XAIModel = response.json().await.map_err(|e| {
            WorkerError::from_api_error(e.to_string(), &crate::types::LlmProvider::XAI)
        })?;

        let supports_tools = true; // Will be determined by config
        let supports_vision = false; // Will be determined by config
        let context_length = None; // Will be determined by config
        let capabilities = vec!["text_generation".to_string()]; // Basic default
        let description = format!("xAI {} model ({})", model_data.id, model_data.owned_by);

        Ok(crate::types::ModelInfo {
            id: model_data.id.clone(),
            name: format!("{} ({})", model_data.id, model_data.owned_by),
            provider: crate::types::LlmProvider::XAI,
            supports_tools,
            supports_function_calling: supports_tools,
            supports_vision,
            supports_multimodal: supports_vision,
            context_length,
            training_cutoff: Some(
                chrono::DateTime::from_timestamp(model_data.created, 0)
                    .map(|dt| dt.format("%Y-%m-%d").to_string())
                    .unwrap_or_else(|| "2024-12-12".to_string()),
            ),
            capabilities,
            description: Some(description),
        })
    }

    pub async fn check_connection(&self) -> Result<(), WorkerError> {
        let client = Client::new();
        let url = UrlConfig::get_completion_url("xai");

        let test_request = XAIRequest {
            model: self.model.clone(),
            messages: vec![XAIMessage {
                role: "user".to_string(),
                content: "Hi".to_string(),
                tool_calls: None,
            }],
            stream: false,
            tools: None,
            max_tokens: Some(10),
            temperature: Some(0.1),
        };

        let response = client
            .post(url)
            .header("Content-Type", "application/json")
            .header("Authorization", format!("Bearer {}", self.api_key))
            .json(&test_request)
            .send()
            .await
            .map_err(|e| {
                WorkerError::from_api_error(e.to_string(), &crate::types::LlmProvider::XAI)
            })?;

        if !response.status().is_success() {
            let status = response.status();
            let error_body = response.text().await.unwrap_or_default();
            return Err(WorkerError::from_api_error(
                format!("xAI connection test failed: {} - {}", status, error_body),
                &crate::types::LlmProvider::XAI,
            ));
        }

        Ok(())
    }
}

#[async_trait::async_trait]
impl LlmClientTrait for XAIClient {
    async fn chat_stream<'a>(
        &'a self,
        messages: Vec<Message>,
        tools: Option<&[DynamicToolDefinition]>,
        llm_debug: Option<crate::types::LlmDebug>,
    ) -> Result<
        Box<dyn Stream<Item = Result<StreamEvent, WorkerError>> + Unpin + Send + 'a>,
        WorkerError,
    > {
        self.chat_stream(messages, tools, llm_debug).await
    }

    async fn check_connection(&self) -> Result<(), WorkerError> {
        self.check_connection().await
    }

    fn provider(&self) -> LlmProvider {
        LlmProvider::XAI
    }

    fn get_model_name(&self) -> String {
        self.get_model_name()
    }
}