implement market overview endpoint

src/main/kotlin/com/frankenergie/smartasset/controller/MarketOverviewController.kt

@@ -0,0 +1,21 @@
+package com.frankenergie.smartasset.controller
+
+import com.frankenergie.smartasset.model.MarketOverviewResponse
+import com.frankenergie.smartasset.model.OrderUpdateRequest
+import com.frankenergie.smartasset.model.OrderUpdateResponse
+import com.frankenergie.smartasset.service.OrderBookService
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@RequestMapping("/api")
+class MarketOverviewController(private val orderBookService: OrderBookService) {
+    @GetMapping("/market/overview")
+    fun getMarketOverview(): ResponseEntity<MarketOverviewResponse> {
+        val response = orderBookService.getMarketOverview()
+        return ResponseEntity.ok(response)
+    }
+}

src/main/kotlin/com/frankenergie/smartasset/model/QuarterOverview.kt

@@ -0,0 +1,12 @@
+package com.frankenergie.smartasset.model
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import java.math.BigDecimal
+import java.time.LocalDateTime
+
+data class QuarterOverview(
+    @JsonProperty("delivery_start_time") val deliveryStartTime: LocalDateTime,
+    @JsonProperty("delivery_end_time") val deliveryEndTime: LocalDateTime,
+    @JsonProperty("highest_buy_price") val highestBuyPrice: BigDecimal?,
+    @JsonProperty("lowest_sell_price") val lowestSellPrice: BigDecimal?
+)

src/main/kotlin/com/frankenergie/smartasset/model/QuarterOverviewResponse.kt

@@ -0,0 +1,9 @@
+package com.frankenergie.smartasset.model
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import java.math.BigDecimal
+import java.time.LocalDateTime
+
+data class MarketOverviewResponse(
+    @JsonProperty("quarters") val quarters: List<QuarterOverview>
+)

src/main/kotlin/com/frankenergie/smartasset/service/OrderBookService.kt

@@ -2,8 +2,10 @@ package com.frankenergie.smartasset.service
 
 import com.frankenergie.smartasset.domain.OrderBook
 import com.frankenergie.smartasset.model.DeliveryPeriod
+import com.frankenergie.smartasset.model.MarketOverviewResponse
 import com.frankenergie.smartasset.model.OrderUpdateRequest
 import com.frankenergie.smartasset.model.OrderUpdateResponse
+import com.frankenergie.smartasset.model.QuarterOverview
 import org.springframework.stereotype.Service
 import java.time.Instant
 import java.util.UUID
@@ -30,5 +32,19 @@ class OrderBookService {
         return OrderUpdateResponse(orderId = orderId, status = status, timestamp = Instant.now())
     }
 
+    fun getMarketOverview(): MarketOverviewResponse {
+        val quarters = orderBook.getAllPeriods()
+            .sortedBy { it.startTime }
+            .map { period ->
+                QuarterOverview(
+                    deliveryStartTime = period.startTime,
+                    deliveryEndTime = period.endTime,
+                    highestBuyPrice = orderBook.getBestBid(period)?.price,
+                    lowestSellPrice = orderBook.getBestAsk(period)?.price
+                )
+            }
+        return MarketOverviewResponse(quarters)
+    }
+
     fun getOrderBook(): OrderBook = orderBook
 }

src/test/kotlin/com/frankenergie/smartasset/controller/MarketOverviewControllerTest.kt

@@ -0,0 +1,82 @@
+package com.frankenergie.smartasset.controller
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.frankenergie.smartasset.model.OrderSide
+import com.frankenergie.smartasset.model.OrderUpdateRequest
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.http.MediaType
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.get
+import org.springframework.test.web.servlet.post
+import java.math.BigDecimal
+import java.time.LocalDateTime
+
+@SpringBootTest
+@AutoConfigureMockMvc
+class MarketOverviewControllerTest {
+
+    @Autowired
+    private lateinit var mockMvc: MockMvc
+
+    @Autowired
+    private lateinit var objectMapper: ObjectMapper
+
+    @Test
+    fun `GET market overview returns empty list when no orders`() {
+        mockMvc.get("/api/market/overview")
+            .andExpect {
+                status { isOk() }
+                jsonPath("$.quarters") { isArray() }
+            }
+    }
+
+    @Test
+    fun `GET market overview returns quarters with best prices`() {
+        // Add a buy order
+        val buyRequest = OrderUpdateRequest(
+            deliveryStartTime = LocalDateTime.of(2024, 6, 15, 10, 0),
+            deliveryEndTime = LocalDateTime.of(2024, 6, 15, 10, 15),
+            orderSide = OrderSide.BUY,
+            quantity = BigDecimal("10"),
+            price = BigDecimal("50.00")
+        )
+        mockMvc.post("/api/orderupdate") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(buyRequest)
+        }
+
+        // Add a higher buy order for same quarter
+        val higherBuyRequest = buyRequest.copy(price = BigDecimal("52.00"))
+        mockMvc.post("/api/orderupdate") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(higherBuyRequest)
+        }
+
+        // Add a sell order
+        val sellRequest = buyRequest.copy(orderSide = OrderSide.SELL, price = BigDecimal("55.00"))
+        mockMvc.post("/api/orderupdate") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(sellRequest)
+        }
+
+        // Add a lower sell order
+        val lowerSellRequest = buyRequest.copy(orderSide = OrderSide.SELL, price = BigDecimal("53.00"))
+        mockMvc.post("/api/orderupdate") {
+            contentType = MediaType.APPLICATION_JSON
+            content = objectMapper.writeValueAsString(lowerSellRequest)
+        }
+
+        mockMvc.get("/api/market/overview")
+            .andExpect {
+                status { isOk() }
+                jsonPath("$.quarters.length()") { value(1) }
+                jsonPath("$.quarters[0].delivery_start_time") { exists() }
+                jsonPath("$.quarters[0].delivery_end_time") { exists() }
+                jsonPath("$.quarters[0].highest_buy_price") { value(52.00) }
+                jsonPath("$.quarters[0].lowest_sell_price") { value(53.00) }
+            }
+    }
+}