use serde::{Deserialize, Serialize};

/// The type of file stored in the knowledge base.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub enum FileKind {
    /// PDF document
    Pdf,
    /// Plain text or markdown file
    Text,
    /// Spreadsheet (csv, xlsx)
    Spreadsheet,
    /// Source code file
    Code,
    /// Image file
    Image,
}

impl FileKind {
    /// Returns the display label for a file kind.
    pub fn label(&self) -> &'static str {
        match self {
            Self::Pdf => "PDF",
            Self::Text => "Text",
            Self::Spreadsheet => "Spreadsheet",
            Self::Code => "Code",
            Self::Image => "Image",
        }
    }

    /// Returns an icon identifier for rendering.
    pub fn icon(&self) -> &'static str {
        match self {
            Self::Pdf => "file-pdf",
            Self::Text => "file-text",
            Self::Spreadsheet => "file-spreadsheet",
            Self::Code => "file-code",
            Self::Image => "file-image",
        }
    }
}

/// A file stored in the knowledge base for RAG retrieval.
///
/// # Fields
///
/// * `id` - Unique file identifier
/// * `name` - Original filename
/// * `kind` - Type classification of the file
/// * `size_bytes` - File size in bytes
/// * `uploaded_at` - ISO 8601 upload timestamp
/// * `chunk_count` - Number of vector chunks created from this file
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct KnowledgeFile {
    pub id: String,
    pub name: String,
    pub kind: FileKind,
    pub size_bytes: u64,
    pub uploaded_at: String,
    pub chunk_count: u32,
}