From 8f0cb4db0e787fb2aaf7337a9106d50ee101174a Mon Sep 17 00:00:00 2001
From: Matthias Fischer <matthias.fischer@doubleslash.de>
Date: Tue, 9 Jul 2024 11:54:15 +0200
Subject: [PATCH] feat(impl):[#750] get policy by id

---
 .../controllers/PolicyStoreController.java    | 46 +++++++++++++++++++
 .../services/PolicyPagingService.java         | 23 ++++++----
 2 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/controllers/PolicyStoreController.java b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/controllers/PolicyStoreController.java
index abb43ba73..c5d1bd553 100644
--- a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/controllers/PolicyStoreController.java
+++ b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/controllers/PolicyStoreController.java
@@ -162,6 +162,52 @@ public CreatePoliciesResponse registerAllowedPolicy(@Valid @RequestBody final Cr
         return CreatePoliciesResponse.fromPolicy(registeredPolicy);
     }
 
+    @Operation(operationId = "getPolicyById", summary = "Gets policy by ID.",
+               security = @SecurityRequirement(name = API_KEY), tags = { POLICY_API_TAG },
+               description = "Gets policy by ID.")
+    @ApiResponses(
+            value = { @ApiResponse(responseCode = "200", description = "Returns the policies as list of policies.",
+                                   content = { @Content(mediaType = APPLICATION_JSON_VALUE,
+                                                        // TODO examples = @ExampleObject(PolicyResponse.BPN_TO_POLICY_MAP_EXAMPLE),
+                                                        schema = @Schema(description = "List of policies"))
+                                   }),
+                      @ApiResponse(responseCode = "401", description = UNAUTHORIZED_DESC,
+                                   content = { @Content(mediaType = APPLICATION_JSON_VALUE,
+                                                        schema = @Schema(implementation = ErrorResponse.class),
+                                                        examples = @ExampleObject(name = "error",
+                                                                                  ref = "#/components/examples/error-response-401"))
+                                   }),
+                      @ApiResponse(responseCode = "403", description = FORBIDDEN_DESC,
+                                   content = { @Content(mediaType = APPLICATION_JSON_VALUE,
+                                                        schema = @Schema(implementation = ErrorResponse.class),
+                                                        examples = @ExampleObject(name = "error",
+                                                                                  ref = "#/components/examples/error-response-403"))
+                                   }),
+            })
+    @GetMapping("/policies/{policyId}")
+    @ResponseStatus(HttpStatus.OK)
+    @PreAuthorize("hasAuthority('" + IrsRoles.ADMIN_IRS + "')")
+    public List<PolicyResponse> getPolicyById(//
+            @PathVariable(required = true) //
+            @ValidPolicyId //
+            @Parameter(description = "Policy ID.") //
+            final String policyId //
+    ) {
+
+        final Map<String, String[]> parameterMap = this.httpServletRequest.getParameterMap();
+
+        final Map<String, List<Policy>> policies = service.getPolicies(null);
+
+        // TODO (mfischer): #750: return only one policy and List of BPN as attribute?!
+        // TODO (mfischer): #750: update insomnia
+        // TODO (mfischer): #750: update swagger
+        // TODO (mfischer): #750: add test
+        return policyPagingService.getPolicyWithBpnStream(policies)
+                                  .filter(p -> p.policy().getPolicyId().equals(policyId))
+                                  .map(p -> PolicyResponse.from(p.policy(), p.bpn()))
+                                  .toList();
+    }
+
     @Operation(operationId = "getAllowedPoliciesByBpn",
                summary = "Lists the registered policies that should be accepted in EDC negotiation.",
                security = @SecurityRequirement(name = API_KEY), tags = { POLICY_API_TAG },
diff --git a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
index fa7d89a4d..2a9d756bd 100644
--- a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
+++ b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
@@ -31,6 +31,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.function.Predicate;
+import java.util.stream.Stream;
 
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
@@ -67,20 +68,22 @@ public Page<PolicyWithBpn> getPolicies(final Map<String, List<Policy>> bpnToPoli
         final Comparator<PolicyWithBpn> comparator = new PolicyComparatorBuilder(pageable).build();
         final Predicate<PolicyWithBpn> filter = new PolicyFilterBuilder(searchCriteria).build();
 
-        final List<PolicyWithBpn> policies = bpnToPoliciesMap.entrySet()
-                                                             .stream()
-                                                             .flatMap(bpnWithPolicies -> bpnWithPolicies.getValue()
-                                                                                                        .stream()
-                                                                                                        .map(policy -> new PolicyWithBpn(
-                                                                                                                bpnWithPolicies.getKey(),
-                                                                                                                policy)))
-                                                             .filter(filter)
-                                                             .sorted(comparator)
-                                                             .toList();
+        final List<PolicyWithBpn> policies = getPolicyWithBpnStream(bpnToPoliciesMap).filter(filter)
+                                                                                     .sorted(comparator)
+                                                                                     .toList();
 
         return applyPaging(pageable, policies);
     }
 
+    public Stream<PolicyWithBpn> getPolicyWithBpnStream(final Map<String, List<Policy>> bpnToPoliciesMap) {
+        return bpnToPoliciesMap.entrySet()
+                               .stream()
+                               .flatMap(bpnWithPolicies -> bpnWithPolicies.getValue()
+                                                                          .stream()
+                                                                          .map(policy -> new PolicyWithBpn(
+                                                                                  bpnWithPolicies.getKey(), policy)));
+    }
+
     private PageImpl<PolicyWithBpn> applyPaging(final Pageable pageable, final List<PolicyWithBpn> policies) {
         final int start = Math.min(pageable.getPageNumber() * pageable.getPageSize(), policies.size());
         final int end = Math.min((pageable.getPageNumber() + 1) * pageable.getPageSize(), policies.size());