dpp-digital-link 0.12.0

//! JSON-LD context envelope: build / frame / strip a DPP passport payload.

use std::sync::OnceLock;

use serde_json::{Value, json};

/// Build a minimal JSON-LD context for an Odal Node passport.
///
/// Suitable for embedding in or linking from a DPP payload to assert
/// semantic interoperability with GS1, Schema.org, and EU ESPR vocabularies.
///
/// The literal is built once and cloned per call — callers extend the
/// returned value (e.g. [`frame_passport`] merges passport fields into it),
/// so it must stay an owned, independently-mutable `Value` per call site.
pub fn passport_context() -> Value {
    static CONTEXT: OnceLock<Value> = OnceLock::new();
    CONTEXT
        .get_or_init(|| {
            json!({
                "@context": [
                    "https://www.w3.org/ns/did/v1",
                    "https://ref.gs1.org/standards/digital-link/context/",
                    {
                        "dpp": "https://schema.odal-node.io/dpp#",
                        "gs1": "https://ref.gs1.org/voc/",
                        "schema": "https://schema.org/",
                        "gtin": "gs1:gtin",
                        "sector": "dpp:sector",
                        "passportId": "dpp:passportId",
                        "status": "dpp:status",
                        "sectorData": "dpp:sectorData",
                        "complianceResult": "dpp:complianceResult",
                        "createdAt": "schema:dateCreated",
                        "updatedAt": "schema:dateModified",
                        "jws": "dpp:jws"
                    }
                ]
            })
        })
        .clone()
}

/// Wrap a passport JSON value in a JSON-LD envelope.
///
/// A non-object payload cannot be merged into the `@context` object; it is
/// returned **unchanged** rather than silently discarded into a bare, empty
/// envelope.
pub fn frame_passport(passport: Value) -> Value {
    match passport {
        Value::Object(passport_map) => {
            let mut framed = passport_context();
            if let Value::Object(ref mut ctx_map) = framed {
                ctx_map.extend(passport_map);
            }
            framed
        }
        other => other,
    }
}

/// Extract the plain data from a JSON-LD framed passport (strip `@context`).
pub fn strip_context(framed: Value) -> Value {
    match framed {
        Value::Object(mut map) => {
            map.remove("@context");
            Value::Object(map)
        }
        other => other,
    }
}