use serde::{Deserialize, Serialize};
use utoipa::ToSchema;

/// Arguments used for cursor-based pagination.
#[derive(Deserialize, Debug, ToSchema)]
#[serde(rename_all = "camelCase")]
pub struct PaginationArgs {
    /// Returns the first `n` items from the list.
    pub first: Option<i64>,

    /// A cursor pointing to the position after which items should be returned.
    pub after: Option<String>,

    /// Returns the last `n` items from the list.
    pub last: Option<i64>,

    /// A cursor pointing to the position before which items should be returned.
    pub before: Option<String>,
}

/// Metadata describing the current page of results.
#[derive(Serialize, Debug, ToSchema)]
#[serde(rename_all = "camelCase")]
pub struct PageInfo {
    /// Indicates whether there are more items when paginating forward.
    pub has_next_page: bool,

    /// Indicates whether there are more items when paginating backward.
    pub has_previous_page: bool,

    /// The cursor corresponding to the first item in the current page.
    pub start_cursor: Option<String>,

    /// The cursor corresponding to the last item in the current page.
    pub end_cursor: Option<String>,
}

/// A paginated connection containing edges and pagination metadata.
#[derive(Serialize, Debug, ToSchema)]
#[serde(rename_all = "camelCase")]
pub struct Connection<T> {
    /// A list of edges, each containing a node and its cursor.
    pub edges: Vec<Edge<T>>,

    /// Information about pagination for this connection.
    pub page_info: PageInfo,
}

/// An edge in a connection, representing a node and its cursor.
#[derive(Serialize, Debug, ToSchema)]
#[serde(rename_all = "camelCase")]
pub struct Edge<T> {
    /// The item/node contained in this edge.
    pub node: T,

    /// A cursor for this node, used in pagination.
    pub cursor: String,
}