Resolve pin via data.gov.in with fallbacks

2026-01-31 11:48:02 +05:30
parent 796d9f35b0
commit e9e39e645c
6 changed files with 189 additions and 27 deletions
--- a/src/main/kotlin/com/android/trisolarisserver/component/PostalPincodeClient.kt
+++ b/src/main/kotlin/com/android/trisolarisserver/component/PostalPincodeClient.kt
@@ -0,0 +1,56 @@
+package com.android.trisolarisserver.component
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.slf4j.LoggerFactory
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.stereotype.Component
+import org.springframework.web.client.RestTemplate
+import org.springframework.web.util.UriComponentsBuilder
+
+@Component
+class PostalPincodeClient(
+    private val restTemplate: RestTemplate,
+    private val objectMapper: ObjectMapper,
+    @Value("\${pincode.postal.baseUrl:https://api.postalpincode.in}")
+    private val baseUrl: String
+) {
+    private val logger = LoggerFactory.getLogger(PostalPincodeClient::class.java)
+
+    fun resolve(pinCode: String): PincodeLookupResult {
+        return try {
+            val url = UriComponentsBuilder.fromUriString(baseUrl)
+                .path("/pincode/{pin}")
+                .buildAndExpand(pinCode)
+                .toUriString()
+            val response = restTemplate.getForEntity(url, String::class.java)
+            val body = response.body ?: return PincodeLookupResult(null, null, "EMPTY_BODY", "postalpincode.in")
+            val resolved = parseCityState(body)
+            val status = if (resolved == null) "ZERO_RESULTS" else "OK"
+            PincodeLookupResult(resolved, body, status, "postalpincode.in")
+        } catch (ex: Exception) {
+            logger.warn("Postalpincode lookup failed: {}", ex.message)
+            PincodeLookupResult(null, null, "ERROR", "postalpincode.in")
+        }
+    }
+
+    private fun parseCityState(body: String): String? {
+        val root = objectMapper.readTree(body)
+        if (!root.isArray || root.isEmpty) return null
+        val first = root.first()
+        val status = first.path("Status").asText(null)
+        if (!status.equals("Success", true)) return null
+        val offices = first.path("PostOffice")
+        if (!offices.isArray || offices.isEmpty) return null
+        val office = chooseOffice(offices) ?: return null
+        val district = office.path("District").asText(null)
+        val state = office.path("State").asText(null)
+        if (district.isNullOrBlank() && state.isNullOrBlank()) return null
+        return listOfNotNull(district?.ifBlank { null }, state?.ifBlank { null }).joinToString(", ")
+    }
+
+    private fun chooseOffice(offices: JsonNode): JsonNode? {
+        val delivery = offices.firstOrNull { it.path("DeliveryStatus").asText("").equals("Delivery", true) }
+        return delivery ?: offices.firstOrNull()
+    }
+}