package cn.iocoder.yudao.module.crm.service.quotation.ai;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import cn.iocoder.yudao.module.ai.api.chat.AiChatApi;
import cn.iocoder.yudao.module.crm.controller.admin.quotation.ai.vo.CrmSaleQuotationOcrReqVO;
import cn.iocoder.yudao.module.crm.controller.admin.quotation.ai.vo.CrmSaleQuotationOcrRespVO;
import cn.iocoder.yudao.module.system.dal.dataobject.storage.SystemStorageBlobDO;
import cn.iocoder.yudao.module.system.service.storage.SystemStorageBlobService;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.apache.pdfbox.Loader;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.text.PDFTextStripper;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xwpf.extractor.XWPFWordExtractor;
import org.apache.poi.xwpf.usermodel.XWPFDocument;
import org.springframework.stereotype.Service;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.math.BigDecimal;
import java.nio.file.Files;
import java.time.LocalDate;
import java.util.*;
import java.util.stream.Collectors;

@Slf4j
@Service
public class CrmSaleQuotationAiServiceImpl implements CrmSaleQuotationAiService {

    private static final Set<String> SUPPORTED_EXTENSIONS = Set.of(
            "pdf", "doc", "docx", "xls", "xlsx", "png", "jpg", "jpeg", "gif", "bmp", "txt", "csv"
    );

    private static final Set<String> IMAGE_EXTENSIONS = Set.of("png", "jpg", "jpeg", "gif", "bmp");

    private static final String SYSTEM_PROMPT = """
            你是一位专业的销售单据数据提取专家。你需要从报价文件中提取结构化信息。

            ## 提取规则
            1. 仔细识别文档中的报价单信息：客户名称、报价日期、有效期、物料明细等
            2. 对于物料明细，每一行提取：物料名称、规格型号、数量、单价
            3. 税率、折扣率等如文件中未明确标注，不填
            4. 日期统一转换为 yyyy-MM-dd 格式
            5. 数字字段仅保留数字，去掉单位

            ## 输出格式
            请按以下JSON格式返回（不要包含其他内容）：
            {"name": "报价单名称", "customerName": "客户名称", "quotationTime": "2026-01-01", "validUntil": "2026-12-31", "taxRate": 13.0, "discountPercent": 5.0, "remark": "备注信息", "items": [{"itemName": "物料名称", "itemSpec": "规格型号", "count": 10.0, "quotationPrice": 100.0}]}

            所有字段均为可选，未提取到的字段不要返回。
            如果文件内容无法识别为报价单，返回空JSON：{}
            """;

    private static final String SYSTEM_PROMPT_IMAGE = """
            你是一位专业的销售单据OCR识别专家。你需要从报价文件图片中提取结构化信息。

            ## 提取规则
            1. 仔细识别图片中的文字信息
            2. 提取报价单相关信息：客户名称、报价日期、有效期、物料明细等
            3. 对于物料明细，每一行提取：物料名称、规格型号、数量、单价
            4. 税率、折扣率等如图片中未明确标注，不填
            5. 日期统一转换为 yyyy-MM-dd 格式

            ## 输出格式
            请按以下JSON格式返回（不要包含其他内容）：
            {"name": "报价单名称", "customerName": "客户名称", "quotationTime": "2026-01-01", "validUntil": "2026-12-31", "taxRate": 13.0, "discountPercent": 5.0, "remark": "备注信息", "items": [{"itemName": "物料名称", "itemSpec": "规格型号", "count": 10.0, "quotationPrice": 100.0}]}

            所有字段均为可选，未提取到的字段不要返回。
            如果图片内容无法识别为报价单，返回空JSON：{}
            """;

    @Resource
    private SystemStorageBlobService blobService;
    @Resource
    private AiChatApi aiChatApi;

    @Override
    public CrmSaleQuotationOcrRespVO ocrQuotation(CrmSaleQuotationOcrReqVO reqVO) {
        File tempFile = null;
        try {
            // 1. 下载文件
            SystemStorageBlobDO blob = blobService.getStorageBlob(reqVO.getBlobId());
            if (blob == null) {
                CrmSaleQuotationOcrRespVO error = new CrmSaleQuotationOcrRespVO();
                error.setRawText("文件不存在");
                return error;
            }

            // 2. 校验文件类型
            String ext = FileUtil.extName(blob.getOriginalFilename()).toLowerCase();
            if (!SUPPORTED_EXTENSIONS.contains(ext)) {
                CrmSaleQuotationOcrRespVO error = new CrmSaleQuotationOcrRespVO();
                error.setRawText("不支持的文件类型，请上传 PDF/Word/Excel/图片文件");
                return error;
            }

            // 3. 获取文件字节
            tempFile = blobService.getPublicFile(blob.getUidFilename(), blob.getResourceKey());
            if (tempFile == null || !tempFile.exists()) {
                CrmSaleQuotationOcrRespVO error = new CrmSaleQuotationOcrRespVO();
                error.setRawText("文件读取失败");
                return error;
            }
            byte[] fileBytes = Files.readAllBytes(tempFile.toPath());

            // 4. AI 识别（图片走多模态，文本走纯文本）
            boolean isImage = IMAGE_EXTENSIONS.contains(ext);
            String systemPrompt = isImage ? SYSTEM_PROMPT_IMAGE : SYSTEM_PROMPT;
            String aiResponse;
            if (isImage) {
                String imageBase64 = Base64.getEncoder().encodeToString(fileBytes);
                String mimeType = getMimeType(ext);
                aiResponse = aiChatApi.chatWithImage(systemPrompt, "请识别图片中的报价信息", imageBase64, mimeType);
            } else {
                String extractedText = extractTextByType(ext, fileBytes);
                if (StrUtil.isEmpty(extractedText)) {
                    CrmSaleQuotationOcrRespVO error = new CrmSaleQuotationOcrRespVO();
                    error.setRawText("文件内容为空，无法识别");
                    return error;
                }
                aiResponse = aiChatApi.chat(systemPrompt, extractedText);
            }
            log.info("AI OCR 识别结果: blobId={}, file={}, response={}",
                    reqVO.getBlobId(), blob.getOriginalFilename(), aiResponse);

            // 5. 解析响应
            CrmSaleQuotationOcrRespVO result = parseOcrResponse(aiResponse);
            return result;

        } catch (Exception e) {
            log.warn("AI OCR 识别失败，blobId={}", reqVO.getBlobId(), e);
            CrmSaleQuotationOcrRespVO fallback = new CrmSaleQuotationOcrRespVO();
            fallback.setRawText("AI 识别暂时不可用，请手动录入");
            return fallback;
        } finally {
            if (tempFile != null && tempFile.exists()) {
                tempFile.delete();
            }
        }
    }

    private String extractTextByType(String ext, byte[] bytes) throws IOException {
        return switch (ext) {
            case "pdf" -> extractPdfText(bytes);
            case "docx", "doc" -> extractDocxText(bytes);
            case "xlsx", "xls" -> extractExcelText(bytes);
            case "txt", "csv" -> new String(bytes, java.nio.charset.StandardCharsets.UTF_8);
            default -> "";
        };
    }

    private String extractPdfText(byte[] bytes) throws IOException {
        try (PDDocument doc = Loader.loadPDF(bytes)) {
            PDFTextStripper stripper = new PDFTextStripper();
            stripper.setSortByPosition(true);
            String text = stripper.getText(doc);
            return StrUtil.isNotBlank(text) ? text.trim() : "";
        }
    }

    private String extractDocxText(byte[] bytes) throws IOException {
        try (XWPFDocument doc = new XWPFDocument(new ByteArrayInputStream(bytes))) {
            try (XWPFWordExtractor extractor = new XWPFWordExtractor(doc)) {
                String text = extractor.getText();
                return StrUtil.isNotBlank(text) ? text.trim() : "";
            }
        }
    }

    private String extractExcelText(byte[] bytes) throws IOException {
        StringBuilder sb = new StringBuilder();
        try (Workbook wb = WorkbookFactory.create(new ByteArrayInputStream(bytes))) {
            for (int i = 0; i < wb.getNumberOfSheets(); i++) {
                Sheet sheet = wb.getSheetAt(i);
                if (i > 0) sb.append("\n--- Sheet: ").append(sheet.getSheetName()).append(" ---\n");
                for (Row row : sheet) {
                    List<String> cellValues = new ArrayList<>();
                    for (Cell cell : row) {
                        cellValues.add(getCellStringValue(cell));
                    }
                    sb.append(String.join("\t", cellValues)).append("\n");
                }
            }
        }
        return sb.toString().trim();
    }

    private String getCellStringValue(Cell cell) {
        return switch (cell.getCellType()) {
            case STRING -> cell.getStringCellValue().trim();
            case NUMERIC -> {
                if (DateUtil.isCellDateFormatted(cell)) {
                    yield cell.getLocalDateTimeCellValue().toLocalDate().toString();
                }
                double v = cell.getNumericCellValue();
                if (v == Math.floor(v) && !Double.isInfinite(v)) {
                    yield String.valueOf((long) v);
                }
                yield String.valueOf(v);
            }
            case BOOLEAN -> String.valueOf(cell.getBooleanCellValue());
            case FORMULA -> {
                try {
                    yield String.valueOf(cell.getNumericCellValue());
                } catch (Exception e) {
                    yield cell.getStringCellValue().trim();
                }
            }
            default -> "";
        };
    }

    private String getMimeType(String ext) {
        return switch (ext) {
            case "jpg", "jpeg" -> "image/jpeg";
            case "gif" -> "image/gif";
            case "bmp" -> "image/bmp";
            default -> "image/png";
        };
    }

    private CrmSaleQuotationOcrRespVO parseOcrResponse(String aiResponse) {
        CrmSaleQuotationOcrRespVO respVO = new CrmSaleQuotationOcrRespVO();
        try {
            String json = aiResponse;
            int start = json.indexOf("{");
            int end = json.lastIndexOf("}");
            if (start >= 0 && end > start) {
                json = json.substring(start, end + 1);
            }
            Map<String, Object> parsed = JSONUtil.toBean(json, Map.class);

            respVO.setName((String) parsed.get("name"));
            respVO.setCustomerName((String) parsed.get("customerName"));
            respVO.setRemark((String) parsed.get("remark"));

            Object qt = parsed.get("quotationTime");
            if (qt instanceof String s && StrUtil.isNotBlank(s)) {
                try { respVO.setQuotationTime(LocalDate.parse(s)); } catch (Exception ignored) {}
            }
            Object vu = parsed.get("validUntil");
            if (vu instanceof String s && StrUtil.isNotBlank(s)) {
                try { respVO.setValidUntil(LocalDate.parse(s)); } catch (Exception ignored) {}
            }
            Object tr = parsed.get("taxRate");
            if (tr instanceof Number n) respVO.setTaxRate(BigDecimal.valueOf(n.doubleValue()));
            Object dp = parsed.get("discountPercent");
            if (dp instanceof Number n) respVO.setDiscountPercent(BigDecimal.valueOf(n.doubleValue()));

            @SuppressWarnings("unchecked")
            List<Map<String, Object>> items = (List<Map<String, Object>>) parsed.get("items");
            if (CollUtil.isNotEmpty(items)) {
                respVO.setItems(items.stream().map(m -> {
                    CrmSaleQuotationOcrRespVO.Item item = new CrmSaleQuotationOcrRespVO.Item();
                    item.setItemName((String) m.get("itemName"));
                    item.setItemSpec((String) m.get("itemSpec"));
                    Object count = m.get("count");
                    if (count instanceof Number n) item.setCount(BigDecimal.valueOf(n.doubleValue()));
                    Object price = m.get("quotationPrice");
                    if (price instanceof Number n) item.setQuotationPrice(BigDecimal.valueOf(n.doubleValue()));
                    return item;
                }).collect(Collectors.toList()));
            }
        } catch (Exception e) {
            log.warn("解析 AI OCR 响应失败: {}", aiResponse, e);
            respVO.setRawText(aiResponse);
        }
        return respVO;
    }

    private String truncate(String text, int maxLen) {
        if (text == null) return "";
        return text.length() > maxLen ? text.substring(0, maxLen) + "..." : text;
    }

}