use crate::agent::core::tools::ToolSchema;
use crate::agent::core::Message;
use crate::agent::llm::api::models::{
    ChatCompletionRequest, ChatCompletionResponse, ChatCompletionStreamChunk, StreamChoice,
    StreamDelta, StreamFunctionCall, StreamToolCall,
};
use crate::agent::llm::protocol::FromProvider;
use crate::agent::llm::providers::anthropic::{
    api_types::{
        AnthropicCompleteRequest, AnthropicCompleteResponse, AnthropicMessagesRequest,
        AnthropicMessagesResponse,
    },
    conversion::{self as anthropic_conversion},
};
use crate::server::error::AppError;

use super::errors::{map_conversion_error, AnthropicError};

pub(super) fn convert_messages_request(
    request: AnthropicMessagesRequest,
) -> Result<ChatCompletionRequest, AnthropicError> {
    anthropic_conversion::convert_messages_request(request).map_err(map_conversion_error)
}

pub(super) fn convert_messages_response(
    response: ChatCompletionResponse,
    response_model: &str,
) -> Result<AnthropicMessagesResponse, AnthropicError> {
    anthropic_conversion::convert_messages_response(response, response_model)
        .map_err(map_conversion_error)
}

pub(super) fn convert_complete_request(
    request: AnthropicCompleteRequest,
) -> Result<ChatCompletionRequest, AnthropicError> {
    anthropic_conversion::convert_complete_request(request).map_err(map_conversion_error)
}

pub(super) fn convert_complete_response(
    response: ChatCompletionResponse,
    response_model: &str,
) -> Result<AnthropicCompleteResponse, AnthropicError> {
    anthropic_conversion::convert_complete_response(response, response_model)
        .map_err(map_conversion_error)
}

pub(super) fn map_stop_reason(reason: Option<&str>) -> String {
    match reason {
        Some("stop") => "end_turn".to_string(),
        Some("length") => "max_tokens".to_string(),
        Some("tool_calls") => "tool_use".to_string(),
        Some(value) => value.to_string(),
        None => "end_turn".to_string(),
    }
}

pub(super) fn map_stop_reason_complete(reason: Option<&str>) -> String {
    match reason {
        Some("length") => "max_tokens".to_string(),
        Some("stop") => "stop_sequence".to_string(),
        Some(value) => value.to_string(),
        None => "stop_sequence".to_string(),
    }
}

/// Convert OpenAI chat messages to internal messages.
pub(super) fn convert_messages(
    chat_messages: Vec<crate::agent::llm::api::models::ChatMessage>,
) -> Result<Vec<Message>, AppError> {
    chat_messages
        .into_iter()
        .map(|msg| {
            Message::from_provider(msg).map_err(|e| {
                AppError::InternalError(anyhow::anyhow!("Failed to convert message: {}", e))
            })
        })
        .collect()
}

/// Convert OpenAI tools to internal tool schemas.
pub(super) fn convert_tools(
    tools: Option<Vec<crate::agent::llm::api::models::Tool>>,
) -> Result<Vec<ToolSchema>, AppError> {
    match tools {
        Some(tools) => tools
            .into_iter()
            .map(|tool| {
                ToolSchema::from_provider(tool).map_err(|e| {
                    AppError::InternalError(anyhow::anyhow!("Failed to convert tool: {}", e))
                })
            })
            .collect(),
        None => Ok(vec![]),
    }
}

/// Convert LLMChunk to OpenAI stream format.
pub(super) fn convert_llm_chunk_to_openai(
    chunk: crate::agent::llm::types::LLMChunk,
    model: &str,
) -> Option<ChatCompletionStreamChunk> {
    match chunk {
        crate::agent::llm::types::LLMChunk::ResponseId(_) => None,
        crate::agent::llm::types::LLMChunk::Token(text) => Some(ChatCompletionStreamChunk {
            id: format!("chatcmpl-{}", uuid::Uuid::new_v4()),
            object: Some("chat.completion.chunk".to_string()),
            created: chrono::Utc::now().timestamp() as u64,
            model: Some(model.to_string()),
            choices: vec![StreamChoice {
                index: 0,
                delta: StreamDelta {
                    role: None,
                    content: Some(text),
                    tool_calls: None,
                },
                finish_reason: None,
            }],
            usage: None,
        }),
        crate::agent::llm::types::LLMChunk::ToolCalls(tool_calls) => {
            let stream_tool_calls: Vec<StreamToolCall> = tool_calls
                .into_iter()
                .enumerate()
                .map(|(idx, tc)| StreamToolCall {
                    index: idx as u32,
                    id: Some(tc.id),
                    tool_type: Some(tc.tool_type),
                    function: Some(StreamFunctionCall {
                        name: Some(tc.function.name),
                        arguments: Some(tc.function.arguments),
                    }),
                })
                .collect();

            Some(ChatCompletionStreamChunk {
                id: format!("chatcmpl-{}", uuid::Uuid::new_v4()),
                object: Some("chat.completion.chunk".to_string()),
                created: chrono::Utc::now().timestamp() as u64,
                model: Some(model.to_string()),
                choices: vec![StreamChoice {
                    index: 0,
                    delta: StreamDelta {
                        role: None,
                        content: None,
                        tool_calls: Some(stream_tool_calls),
                    },
                    finish_reason: None,
                }],
                usage: None,
            })
        }
        crate::agent::llm::types::LLMChunk::ReasoningToken(_) => None,
        crate::agent::llm::types::LLMChunk::Done => Some(ChatCompletionStreamChunk {
            id: format!("chatcmpl-{}", uuid::Uuid::new_v4()),
            object: Some("chat.completion.chunk".to_string()),
            created: chrono::Utc::now().timestamp() as u64,
            model: Some(model.to_string()),
            choices: vec![StreamChoice {
                index: 0,
                delta: StreamDelta {
                    role: None,
                    content: None,
                    tool_calls: None,
                },
                finish_reason: Some("stop".to_string()),
            }],
            usage: None,
        }),
    }
}
