package jnpf.fileStorage.dms;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import jnpf.dmsEntity.storage.form.DmsFileUploadRegisterForm;
import jnpf.exception.DataException;
import jnpf.model.filecontent.FileContentImportForm;
import jnpf.model.filecontent.FileContentReceipt;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Path;
import java.util.Locale;

/** Adapts the existing reader and storage method; never invokes registration or workflow callbacks. */
@Service
@RequiredArgsConstructor
public class FileContentImportService {
    private final DmsCommonFileReader reader;
    private final DmsFileStorageService storage;
    private final DmsApprovalPageMergeService approvalPageMergeService;
    private final DmsQianpiyeDocxWriter qianpiyeDocxWriter;
    private final DmsDocxCommentCleaner commentCleaner;
    private final ObjectMapper json;

    public boolean sameContent(jnpf.model.filecontent.FileContentComparisonForm form) {
        try {
            JsonNode before = json.readTree(form.getOriginal()), after = json.readTree(form.getCandidate());
            if (before == null || after == null || !before.isArray() || !after.isArray()
                    || before.isEmpty() || before.size() != after.size() || before.size() > 100)
                throw new DataException("文件内容比较参数无效");
            for (int i = 0; i < before.size(); i++) {
                if (!digest(before.get(i)).equals(digest(after.get(i)))) return false;
            }
            return true;
        } catch (java.io.IOException invalid) { throw new DataException("文件内容比较参数无效"); }
    }

    private String digest(JsonNode file) {
        // Existing local storage resolver rejects arbitrary URL fetching and traversal.
        return reader.withFile(file.path("url").asText(), file.toString(), "内容校验", source -> {
            try (InputStream input = source.getInputStream()) {
                return cn.hutool.crypto.digest.DigestUtil.sha256Hex(input);
            } catch (IOException failure) { throw new DataException("无法读取附件内容，请稍后重试"); }
        });
    }

    public FileContentReceipt importContent(FileContentImportForm form) {
        DmsFileUploadRegisterForm stored = reader.withFile(singleFileUrl(form.getFileJson()),
                form.getFileJson(), form.getFileName(), file -> store(form, file));
        FileContentReceipt receipt = new FileContentReceipt();
        BeanUtils.copyProperties(stored, receipt);
        return receipt;
    }

    private DmsFileUploadRegisterForm store(FileContentImportForm form, MultipartFile file) {
        String approvalPage = form.getSignaturePageFiles();
        MultipartFile source = isDocx(file) && form.getSignaturePageValues() != null
                && approvalPage != null && !approvalPage.isBlank()
                ? approvalPageMergeService.withoutApprovalPages(file) : file;
        MultipartFile renderedFile = isDocx(file) && form.getSignaturePageValues() != null
                ? qianpiyeDocxWriter.render(source, form.getSignaturePageValues(),
                        form.getApprovalFlowVersionId()) : file;
        if (approvalPage == null || approvalPage.isBlank() || !isDocx(file)) {
            return storeFormal(form, renderedFile);
        }
        return reader.withFile(singleFileUrl(approvalPage), approvalPage, "签批页", page -> {
            MultipartFile rendered = isDocx(page)
                    ? qianpiyeDocxWriter.render(page, form.getSignaturePageValues(),
                            form.getApprovalFlowVersionId()) : page;
            MultipartFile merged = approvalPageMergeService.replaceOrPrepend(renderedFile, rendered);
            return storeFormal(form, merged);
        });
    }

    private DmsFileUploadRegisterForm storeFormal(FileContentImportForm form, MultipartFile file) {
        MultipartFile formal = form.isRemoveDocxComments() && isDocx(file) ? commentCleaner.clean(file) : file;
        return storage.storeWorkflowContent(form.getDocumentId(), form.getFileVersionId(),
                withDocumentName(formal, form.getFileName(), file.getOriginalFilename()));
    }

    // Rename only formal content, after signature-page merging and comment cleanup.
    // Keep the source extension so a business title cannot change the file format.
    private MultipartFile withDocumentName(MultipartFile file, String documentName, String sourceName) {
        if (documentName == null || documentName.isBlank()) {
            throw new DataException("文件名称不能为空");
        }
        String name = documentName.trim();
        int dot = sourceName == null ? -1 : sourceName.lastIndexOf('.');
        String extension = dot < 0 ? "" : sourceName.substring(dot);
        if (!extension.isEmpty() && !name.toLowerCase(Locale.ROOT).endsWith(extension.toLowerCase(Locale.ROOT))) {
            name += extension;
        }
        return name.equals(file.getOriginalFilename()) ? file : new NamedMultipartFile(file, name);
    }

    private record NamedMultipartFile(MultipartFile delegate, String filename) implements MultipartFile {
        @Override public String getName() { return delegate.getName(); }
        @Override public String getOriginalFilename() { return filename; }
        @Override public String getContentType() { return delegate.getContentType(); }
        @Override public boolean isEmpty() { return delegate.isEmpty(); }
        @Override public long getSize() { return delegate.getSize(); }
        @Override public byte[] getBytes() throws IOException { return delegate.getBytes(); }
        @Override public InputStream getInputStream() throws IOException { return delegate.getInputStream(); }
        @Override public void transferTo(File dest) throws IOException { delegate.transferTo(dest); }
        @Override public void transferTo(Path dest) throws IOException { delegate.transferTo(dest); }
    }

    private boolean isDocx(MultipartFile file) {
        String name = file == null ? null : file.getOriginalFilename();
        return name != null && name.toLowerCase(java.util.Locale.ROOT).endsWith(".docx");
    }

    private String singleFileUrl(String fileJson) {
        try {
            JsonNode value = json.readTree(fileJson);
            if (value != null && value.isArray()) {
                if (value.size() != 1) throw new DataException("每次导入必须有且只有一个物理文件");
                value = value.get(0);
            }
            JsonNode url = value == null ? null : value.get("url");
            if (url == null || !url.isTextual() || url.textValue().isBlank())
                throw new DataException("附件缺少URL");
            return url.textValue();
        } catch (JsonProcessingException e) {
            throw new DataException("附件格式不正确");
        }
    }
}