lenso_api/
openapi.rs

1//! `OpenAPI` document assembly.
2//!
3//! Paths and component schemas are derived directly from the
4//! `#[utoipa::path]`-annotated handlers via `utoipa-axum`'s `OpenApiRouter`, so
5//! there is a single source of truth per endpoint. This module contributes the
6//! document-level metadata (info, tags) and normalizes shared platform error
7//! responses after linked/module routers are merged.
8
9use lenso_bootstrap::CompositionProfile;
10use platform_core::AppContext;
11use platform_http::{ApiOpenApiRouter, OpenApiRouter, base_router};
12use utoipa::OpenApi;
13use utoipa::openapi::RefOr;
14use utoipa::openapi::content::Content;
15use utoipa::openapi::path::Operation;
16use utoipa::openapi::response::Response;
17
18/// Document-level `OpenAPI` metadata shared by every endpoint.
19///
20/// Intentionally declares no `paths` and no per-endpoint `schemas`: those are
21/// collected automatically from the annotated handlers when the router is split
22/// into its parts.
23#[derive(OpenApi)]
24#[openapi(
25    info(
26        title = "Lenso API",
27        version = "1.0.0",
28        description = "Rust-first modular monolith API contract"
29    ),
30    tags((name = "auth", description = "Auth module development session APIs"))
31)]
32struct ApiDoc;
33
34/// Assemble the full `OpenAPI` router: base probes, linked module routes, and
35/// admin/runtime routers, seeded with the document-level metadata.
36///
37/// Context-free: route registration and `OpenAPI` metadata never touch the
38/// database, so callers can either serve it (after `with_state` +
39/// `split_for_parts`) or extract the `OpenAPI` document alone.
40pub(crate) fn api_router() -> ApiOpenApiRouter {
41    api_router_for_profile(CompositionProfile::default())
42}
43
44pub(crate) fn api_router_for_profile(profile: CompositionProfile) -> ApiOpenApiRouter {
45    let base = OpenApiRouter::with_openapi(openapi_document_for_profile_with_composition(
46        profile,
47        &lenso_bootstrap::HostComposition::default(),
48    ))
49    .merge(base_router());
50    lenso_bootstrap::merge_linked_http_for_profile(base, profile).merge(platform_provider::router())
51}
52
53pub(crate) fn api_router_for_context_with_composition(
54    ctx: &AppContext,
55    composition: &lenso_bootstrap::HostComposition,
56) -> platform_core::AppResult<ApiOpenApiRouter> {
57    let profile = CompositionProfile::from_config(&ctx.config)?;
58    let base = OpenApiRouter::with_openapi(openapi_document_for_profile_with_composition(
59        profile,
60        composition,
61    ))
62    .merge(base_router());
63    let router =
64        lenso_bootstrap::merge_linked_http_for_context_with_composition(base, ctx, composition)?;
65    Ok(router.merge(platform_provider::router()))
66}
67
68fn openapi_document_for_profile_with_composition(
69    profile: CompositionProfile,
70    composition: &lenso_bootstrap::HostComposition,
71) -> utoipa::openapi::OpenApi {
72    let mut document = ApiDoc::openapi();
73    if let Some(tags) = &mut document.tags {
74        let has_auth = profile == CompositionProfile::Demo
75            || composition
76                .linked_modules()
77                .iter()
78                .any(|module| module.module_name == "auth");
79        match profile {
80            CompositionProfile::Core => tags.retain(|tag| has_auth || tag.name != "auth"),
81            CompositionProfile::Demo => {}
82        }
83    }
84    document
85}
86
87/// The committed `OpenAPI` document, derived from the annotated handlers.
88#[must_use]
89pub fn openapi_document() -> utoipa::openapi::OpenApi {
90    let mut document = api_router().to_openapi();
91    normalize_error_response_content_types(&mut document);
92    document
93}
94
95pub(crate) fn normalize_error_response_content_types(document: &mut utoipa::openapi::OpenApi) {
96    for path_item in document.paths.paths.values_mut() {
97        normalize_operation_error_responses(path_item.get.as_mut());
98        normalize_operation_error_responses(path_item.put.as_mut());
99        normalize_operation_error_responses(path_item.post.as_mut());
100        normalize_operation_error_responses(path_item.delete.as_mut());
101        normalize_operation_error_responses(path_item.options.as_mut());
102        normalize_operation_error_responses(path_item.head.as_mut());
103        normalize_operation_error_responses(path_item.patch.as_mut());
104        normalize_operation_error_responses(path_item.trace.as_mut());
105    }
106}
107
108fn normalize_operation_error_responses(operation: Option<&mut Operation>) {
109    let Some(operation) = operation else {
110        return;
111    };
112    for response in operation.responses.responses.values_mut() {
113        if let RefOr::T(response) = response {
114            normalize_response_error_content_type(response);
115        }
116    }
117}
118
119fn normalize_response_error_content_type(response: &mut Response) {
120    let Some(content) = response.content.get("application/json") else {
121        return;
122    };
123    if !is_error_response_content(content) {
124        return;
125    }
126
127    let content = response
128        .content
129        .shift_remove("application/json")
130        .expect("application/json content should exist");
131    response
132        .content
133        .insert("application/problem+json".to_owned(), content);
134}
135
136fn is_error_response_content(content: &Content) -> bool {
137    matches!(
138        &content.schema,
139        Some(RefOr::Ref(reference))
140            if reference.ref_location == "#/components/schemas/ErrorResponse"
141    )
142}
lenso_api/openapi.rs

lenso_api/
openapi.rs
