package com.goldenchart.controller;

import com.goldenchart.dto.VerificationIssueImageDto;
import com.goldenchart.service.VerificationIssueImageService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.util.List;
import java.util.Map;

@RestController
@RequestMapping("/verification-issues/{issueId}/images")
@RequiredArgsConstructor
@Slf4j
public class VerificationIssueImageController {

    private final VerificationIssueImageService service;

    @GetMapping
    public ResponseEntity<List<VerificationIssueImageDto>> list(@PathVariable Long issueId) {
        return ResponseEntity.ok(service.listByIssue(issueId));
    }

    @PostMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public ResponseEntity<?> upload(
            @PathVariable Long issueId,
            @RequestParam("files") List<MultipartFile> files) {
        try {
            return ResponseEntity.ok(service.upload(issueId, files));
        } catch (IllegalArgumentException e) {
            log.warn("[VerificationImage] upload rejected issueId={}: {}", issueId, e.getMessage());
            return ResponseEntity.badRequest().body(Map.of("message", toUserMessage(e.getMessage())));
        } catch (IOException e) {
            log.error("[VerificationImage] upload io error issueId={}", issueId, e);
            return ResponseEntity.internalServerError()
                    .body(Map.of("message", "이미지 저장에 실패했습니다. 잠시 후 다시 시도하세요."));
        }
    }

    private static String toUserMessage(String code) {
        if (code == null) return "업로드할 수 없습니다.";
        return switch (code) {
            case "unsupported image type" -> "지원하지 않는 이미지 형식입니다. (jpeg, png, gif, webp, bmp)";
            case "file too large" -> "이미지 크기는 파일당 5MB 이하여야 합니다.";
            case "no files", "no valid image files" -> "업로드할 이미지가 없습니다.";
            default -> code.startsWith("max images exceeded")
                    ? "이슈당 첨부 이미지는 최대 30장까지입니다."
                    : code.startsWith("issue not found") ? "검증 이슈를 찾을 수 없습니다." : code;
        };
    }

    @GetMapping("/{imageId}/file")
    public ResponseEntity<Resource> file(
            @PathVariable Long issueId,
            @PathVariable Long imageId) {
        return service.loadFile(issueId, imageId)
                .map(resource -> {
                    String type = service.contentType(issueId, imageId).orElse(MediaType.APPLICATION_OCTET_STREAM_VALUE);
                    return ResponseEntity.ok()
                            .contentType(MediaType.parseMediaType(type))
                            .header(HttpHeaders.CACHE_CONTROL, "private, max-age=3600")
                            .body(resource);
                })
                .orElse(ResponseEntity.notFound().build());
    }

    @DeleteMapping("/{imageId}")
    public ResponseEntity<Void> delete(
            @PathVariable Long issueId,
            @PathVariable Long imageId) {
        try {
            if (!service.delete(issueId, imageId)) {
                return ResponseEntity.notFound().build();
            }
            return ResponseEntity.noContent().build();
        } catch (IOException e) {
            return ResponseEntity.internalServerError().build();
        }
    }
}