package com.mydreamjob.offer;

import com.mydreamjob.audit.AuditContext;
import com.mydreamjob.common.api.ApiResponse;
import com.mydreamjob.common.exception.BusinessException;
import com.mydreamjob.common.exception.ErrorCode;
import com.mydreamjob.offer.dto.CounterOfferCreateRequest;
import com.mydreamjob.offer.dto.OfferCreateRequest;
import com.mydreamjob.offer.dto.OfferStatusRequest;
import com.mydreamjob.offer.dto.OfferUpdateRequest;
import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.tags.Tag;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.validation.Valid;
import lombok.RequiredArgsConstructor;
import org.springframework.data.domain.Page;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * Offer 管理接口（录用邀请）
 */
@Tag(name = "Offer", description = "企业录用邀请：创建、发送、接受/拒绝/洽谈、到期失效、提醒与时间线")
@RestController
@RequestMapping("/offers")
@RequiredArgsConstructor
public class OfferController {

    /** R01-A2：身份只来自安全上下文，不接受请求参数传入的 userId。 */
    private final com.mydreamjob.security.CurrentUserAccessor currentUserAccessor;
    /** R01-A2：requestId 只来自过滤器规范化后的唯一产出点。 */
    private final com.mydreamjob.common.logging.RequestIdAccessor requestIdAccessor;

    private final OfferService offerService;

    @Operation(summary = "创建 Offer", description = "仅企业账号；投递存在、岗位属于本企业、投递状态可发、无有效 Offer；默认 DRAFT")
    @PostMapping
    public ResponseEntity<ApiResponse<Map<String, Object>>> create(
            @Valid @RequestBody OfferCreateRequest req,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Offer offer = offerService.createOffer(userId, req, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toView(offer), requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 列表", description = "候选人查看收到的、企业查看发出的 Offer；支持 status、applicationId 筛选与分页")
    @GetMapping
    public ResponseEntity<ApiResponse<Map<String, Object>>> list(
            @RequestParam(required = false) String status,
            @RequestParam(required = false) Long applicationId,
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "20") int size,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Page<Offer> result = offerService.listOffers(userId, status, applicationId, page, size);
        Map<String, Object> data = new HashMap<>();
        data.put("items", result.getContent().stream().map(offerService::toView).collect(Collectors.toList()));
        data.put("total", result.getTotalElements());
        data.put("page", result.getNumber());
        data.put("size", result.getSize());
        data.put("totalPages", result.getTotalPages());
        return ResponseEntity.ok(ApiResponse.ok(data, requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 详情", description = "仅目标候选人、所属企业可访问；其他账号返回无权限错误")
    @GetMapping("/{id}")
    public ResponseEntity<ApiResponse<Map<String, Object>>> get(
            @PathVariable Long id,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Offer offer = offerService.getOffer(id, userId);
        return ResponseEntity.ok(ApiResponse.ok(offerService.toView(offer), requestIdAccessor.get(request)));
    }

    @Operation(summary = "修改 Offer", description = "仅所属企业、仅 DRAFT 状态可修改；其余状态返回业务错误")
    @PutMapping("/{id:\\d+}")
    public ResponseEntity<ApiResponse<Map<String, Object>>> update(
            @PathVariable Long id,
            @Valid @RequestBody OfferUpdateRequest req,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Offer offer = offerService.updateOffer(userId, id, req, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toView(offer), requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 状态变更", description = "DRAFT→SENT 企业；SENT/NEGOTIATING→ACCEPTED/REJECTED/NEGOTIATING 候选人；重复提交幂等")
    @PatchMapping("/{id:\\d+}/status")
    public ResponseEntity<ApiResponse<Map<String, Object>>> changeStatus(
            @PathVariable Long id,
            @Valid @RequestBody OfferStatusRequest req,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Offer offer = offerService.transitionStatus(userId, id, req, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toView(offer), requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 状态时间线", description = "完整状态变更历史，含操作者、原因与请求 ID")
    @GetMapping("/{id:\\d+}/timeline")
    public ResponseEntity<ApiResponse<List<Map<String, Object>>>> timeline(
            @PathVariable Long id,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        List<Map<String, Object>> data = offerService.getTimeline(id, userId);
        return ResponseEntity.ok(ApiResponse.ok(data, requestIdAccessor.get(request)));
    }

    @Operation(summary = "手动提醒", description = "仅所属企业；仅 SENT/NEGOTIATING 可提醒；相同提醒不重复创建")
    @PostMapping("/{id:\\d+}/remind")
    public ResponseEntity<ApiResponse<Map<String, Object>>> remind(
            @PathVariable Long id,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        OfferReminder reminder = offerService.remind(userId, id, AuditContext.from(request));
        Map<String, Object> data = new HashMap<>();
        data.put("offerId", reminder.getOfferId());
        data.put("reminderType", reminder.getReminderType());
        data.put("status", reminder.getStatus());
        data.put("sentAt", reminder.getSentAt());
        return ResponseEntity.ok(ApiResponse.ok(data, requestIdAccessor.get(request)));
    }

    // ── Offer 进阶接口 ─────────────────────────────────────────

    @Operation(summary = "发起还价", description = "仅候选人本人；仅 SENT/NEGOTIATING 可发起；SENT 时自动进入 NEGOTIATING")
    @PostMapping("/{id:\\d+}/counter-offers")
    public ResponseEntity<ApiResponse<Map<String, Object>>> createCounterOffer(
            @PathVariable Long id,
            @Valid @RequestBody CounterOfferCreateRequest req,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        OfferCounterOffer co = offerService.createCounterOffer(userId, id, req, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toCounterOfferView(co), requestIdAccessor.get(request)));
    }

    @Operation(summary = "还价列表", description = "候选人查看本人 Offer 的还价、企业查看本企业 Offer 的还价")
    @GetMapping("/{id:\\d+}/counter-offers")
    public ResponseEntity<ApiResponse<List<Map<String, Object>>>> listCounterOffers(
            @PathVariable Long id,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        List<Map<String, Object>> items = offerService.getCounterOffers(id, userId)
                .stream().map(offerService::toCounterOfferView).collect(Collectors.toList());
        return ResponseEntity.ok(ApiResponse.ok(items, requestIdAccessor.get(request)));
    }

    @Operation(summary = "接受还价", description = "仅所属企业；接受后更新 Offer 薪资/入职日期并变为 ACCEPTED")
    @PatchMapping("/{id:\\d+}/counter-offers/{coId:\\d+}/accept")
    public ResponseEntity<ApiResponse<Map<String, Object>>> acceptCounterOffer(
            @PathVariable Long id,
            @PathVariable Long coId,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        OfferCounterOffer co = offerService.acceptCounterOffer(userId, id, coId, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toCounterOfferView(co), requestIdAccessor.get(request)));
    }

    @Operation(summary = "拒绝还价", description = "仅所属企业；拒绝后 Offer 保持 NEGOTIATING")
    @PatchMapping("/{id:\\d+}/counter-offers/{coId:\\d+}/reject")
    public ResponseEntity<ApiResponse<Map<String, Object>>> rejectCounterOffer(
            @PathVariable Long id,
            @PathVariable Long coId,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        OfferCounterOffer co = offerService.rejectCounterOffer(userId, id, coId, AuditContext.from(request));
        return ResponseEntity.ok(ApiResponse.ok(offerService.toCounterOfferView(co), requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 比较", description = "仅候选人本人；比较 2-5 个非 DRAFT 的 Offer")
    @GetMapping("/compare")
    public ResponseEntity<ApiResponse<List<Map<String, Object>>>> compare(
            @RequestParam("ids") String idsParam,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        List<Long> ids = parseIds(idsParam);
        List<Map<String, Object>> items = offerService.compareOffers(userId, ids);
        return ResponseEntity.ok(ApiResponse.ok(items, requestIdAccessor.get(request)));
    }

    @Operation(summary = "Offer 统计", description = "仅企业；统计本企业 Offer 状态分布、接受率、平均响应时间")
    @GetMapping("/statistics")
    public ResponseEntity<ApiResponse<Map<String, Object>>> statistics(
            @RequestParam(required = false, defaultValue = "6") Integer months,
            HttpServletRequest request) {
        Long userId = currentUserAccessor.requireUserId();
        Map<String, Object> data = offerService.getStatistics(userId, months);
        return ResponseEntity.ok(ApiResponse.ok(data, requestIdAccessor.get(request)));
    }

    /**
     * 解析逗号分隔的 Offer id 列表。
     * 非数字、空值或非法值一律返回 400/1001，绝不抛出 500。
     */
    private List<Long> parseIds(String idsParam) {
        List<Long> ids = new ArrayList<>();
        if (idsParam == null || idsParam.isBlank()) {
            throw new BusinessException(ErrorCode.BAD_REQUEST, "ids is required");
        }
        for (String token : idsParam.split(",")) {
            String part = token.trim();
            if (part.isEmpty()) {
                throw new BusinessException(ErrorCode.BAD_REQUEST, "invalid offer id");
            }
            try {
                Long id = Long.valueOf(part);
                if (id <= 0) {
                    throw new BusinessException(ErrorCode.BAD_REQUEST, "invalid offer id");
                }
                ids.add(id);
            } catch (NumberFormatException e) {
                throw new BusinessException(ErrorCode.BAD_REQUEST, "invalid offer id");
            }
        }
        return ids;
    }

}