package com.aiteacher.config;

import com.aiteacher.figure.FigureStorageService;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.server.ResponseStatusException;

import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * Serves figure images by redirecting to a presigned S3 URL.
 * The key stored in DB is the full S3 object key, e.g. "figures/{bookId}/{figureId}.png".
 */
@RestController
@RequestMapping("/api/v1/figures")
public class FigureStorageConfig {

    private final FigureStorageService figureStorageService;

    public FigureStorageConfig(FigureStorageService figureStorageService) {
        this.figureStorageService = figureStorageService;
    }

    @GetMapping("/{bookId}/{filename}")
    public void serve(@PathVariable String bookId,
                      @PathVariable String filename,
                      HttpServletResponse response) throws IOException {
        String key = "figures/" + bookId + "/" + filename;
        try {
            String url = figureStorageService.presignedUrl(key);
            response.sendRedirect(url);
        } catch (Exception ex) {
            throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Figure not found: " + key);
        }
    }
}