use serde::{Deserialize, Serialize};

/// Supported LLM provider backends.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum LlmProvider {
    /// Self-hosted models via Ollama
    Ollama,
    /// Hugging Face Inference API
    HuggingFace,
    /// OpenAI-compatible endpoints
    OpenAi,
    /// Anthropic Claude API
    Anthropic,
}

impl LlmProvider {
    /// Returns the display name for a provider.
    pub fn label(&self) -> &'static str {
        match self {
            Self::Ollama => "Ollama",
            Self::HuggingFace => "Hugging Face",
            Self::OpenAi => "OpenAI",
            Self::Anthropic => "Anthropic",
        }
    }
}

/// A model available from a provider.
///
/// # Fields
///
/// * `id` - Unique model identifier (e.g. "llama3.1:8b")
/// * `name` - Human-readable display name
/// * `provider` - Which provider hosts this model
/// * `context_window` - Maximum context length in tokens
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ModelEntry {
    pub id: String,
    pub name: String,
    pub provider: LlmProvider,
    pub context_window: u32,
}

/// An embedding model available from a provider.
///
/// # Fields
///
/// * `id` - Unique embedding model identifier
/// * `name` - Human-readable display name
/// * `provider` - Which provider hosts this model
/// * `dimensions` - Output embedding dimensions
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct EmbeddingEntry {
    pub id: String,
    pub name: String,
    pub provider: LlmProvider,
    pub dimensions: u32,
}

/// Active provider configuration state.
///
/// # Fields
///
/// * `provider` - Currently selected provider
/// * `selected_model` - ID of the active chat model
/// * `selected_embedding` - ID of the active embedding model
/// * `api_key_set` - Whether an API key has been configured
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ProviderConfig {
    pub provider: LlmProvider,
    pub selected_model: String,
    pub selected_embedding: String,
    pub api_key_set: bool,
}