stocks-be/src/main/java/com/danielbohry/stocks/api/stock/StockController.java

package com.danielbohry.stocks.api.stock;

import com.danielbohry.stocks.domain.Quote;
import com.danielbohry.stocks.service.StockService;
import io.swagger.v3.oas.annotations.Hidden;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.util.List;
import java.util.Objects;

import static java.nio.charset.StandardCharsets.UTF_8;
import static java.time.LocalDateTime.now;
import static java.util.Collections.emptyList;

@Slf4j
@RestController
@RequestMapping("api/stocks")
@AllArgsConstructor
@CrossOrigin
public class StockController {

    private final StockService service;

    @GetMapping
    public ResponseEntity<List<Quote>> find(@RequestParam(value = "q", required = false) String query) {
        if (query == null) {
            return ResponseEntity.ok(emptyList());
        }

        List<Quote> response = service.get(query);
        return ResponseEntity.ok(response);
    }

    @GetMapping("{code}")
    public ResponseEntity<Quote> getByCode(@PathVariable String code) {
        Quote response = service.getByCode(code.toUpperCase());
        return ResponseEntity.ok(response);
    }

    @Hidden
    @PostMapping("/upload-csv")
    public ResponseEntity<StockUploadCSVResponse> uploadCsvFile(@RequestParam("file") MultipartFile file, @RequestParam("currency") String currency) {
        if (file.isEmpty()) {
            return ResponseEntity.badRequest().build();
        }

        try (BufferedReader reader = new BufferedReader(new InputStreamReader(file.getInputStream(), UTF_8))) {
            List<Quote> quotes = reader.lines()
                    .map(r -> convert(r, currency))
                    .filter(Objects::nonNull)
                    .toList();

            List<Quote> response = service.update(quotes);

            return ResponseEntity.ok(new StockUploadCSVResponse(response.size() + " entries updated."));
        } catch (Exception e) {
            log.error("Failed to import csv", e);
            return ResponseEntity.status(400).build();
        }
    }

    private Quote convert(String input, String currency) {
        String[] value = input.split(",");

        log.info("Importing [{}]", (Object) value);

        if (value[3] != null && !value[3].equals("#N/A")) {
            BigDecimal price = new BigDecimal(value[3]);
            return price.compareTo(BigDecimal.ZERO) > 0
                    ? new Quote(value[0], value[1], currency, price, now())
                    : null;
        } else if (value[0] != null && Objects.equals(value[3], "#N/A")) {
            return null;
        } else {
            return null;
        }

    }

}