//! OpenAI-compatible request and response types.
//!
//! These are a subset sufficient for chat completions (streaming + non-streaming).
//! Fields not relevant to proxying are captured as `serde_json::Value` via
//! `#[serde(flatten)]` so we forward them without needing to enumerate every
//! extension field mistral.rs supports.

use serde::{Deserialize, Serialize};
use serde_json::Value;

// ── Chat completion request ──────────────────────────────────────────

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChatCompletionRequest {
    pub model: String,
    pub messages: Vec<ChatMessage>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub temperature: Option<f64>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub top_p: Option<f64>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub max_tokens: Option<u64>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub stream: Option<bool>,
    /// All other fields (tools, response_format, mistral.rs extensions, etc.)
    #[serde(flatten)]
    pub extra: Value,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChatMessage {
    pub role: String,
    pub content: MessageContent,
    #[serde(flatten)]
    pub extra: Value,
}

/// Content can be a simple string or an array of content parts (for vision).
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(untagged)]
pub enum MessageContent {
    Text(String),
    Parts(Vec<Value>),
}

// ── Chat completion response (non-streaming) ─────────────────────────

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChatCompletionResponse {
    pub id: String,
    pub object: String,
    pub created: u64,
    pub model: String,
    pub choices: Vec<ChatCompletionChoice>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub usage: Option<Usage>,
    #[serde(flatten)]
    pub extra: Value,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChatCompletionChoice {
    pub index: u32,
    pub message: ChatMessage,
    pub finish_reason: Option<String>,
    #[serde(flatten)]
    pub extra: Value,
}

// ── Streaming chunk ──────────────────────────────────────────────────

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChatCompletionChunk {
    pub id: String,
    pub object: String,
    pub created: u64,
    pub model: String,
    pub choices: Vec<ChunkChoice>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub usage: Option<Usage>,
    #[serde(flatten)]
    pub extra: Value,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ChunkChoice {
    pub index: u32,
    pub delta: Value,
    pub finish_reason: Option<String>,
    #[serde(flatten)]
    pub extra: Value,
}

// ── Usage ────────────────────────────────────────────────────────────

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Usage {
    pub prompt_tokens: u64,
    pub completion_tokens: u64,
    pub total_tokens: u64,
}

// ── Models list response ─────────────────────────────────────────────

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ModelsResponse {
    pub object: String,
    pub data: Vec<ModelObject>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ModelObject {
    pub id: String,
    pub object: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub owned_by: Option<String>,
    /// Gateway extensions: which node(s) host this model.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub locations: Option<Vec<super::node::ModelLocation>>,
    #[serde(flatten)]
    pub extra: Value,
}