package handler

import (
	"dd_fiber_api/internal/question"
	"dd_fiber_api/internal/question/service"
	"strconv"
	"strings"

	"github.com/gofiber/fiber/v2"
)

// QuestionHandler 题目处理器
type QuestionHandler struct {
	questionService      *service.QuestionService
	knowledgeTreeService *service.KnowledgeTreeService
}

// NewQuestionHandler 创建题目处理器
func NewQuestionHandler(questionService *service.QuestionService, knowledgeTreeService *service.KnowledgeTreeService) *QuestionHandler {
	return &QuestionHandler{
		questionService:      questionService,
		knowledgeTreeService: knowledgeTreeService,
	}
}

// CreateQuestion 创建题目
func (h *QuestionHandler) CreateQuestion(c *fiber.Ctx) error {
	var req service.CreateQuestionRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "请求参数解析失败: " + err.Error(),
		})
	}

	question, err := h.questionService.CreateQuestion(&req)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	return c.JSON(fiber.Map{
		"success":  true,
		"message":  "创建成功",
		"question": question,
	})
}

// GetQuestion 获取题目
func (h *QuestionHandler) GetQuestion(c *fiber.Ctx) error {
	id := c.Query("id")
	if id == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "题目ID不能为空",
		})
	}

	question, err := h.questionService.GetQuestion(id)
	if err != nil {
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	return c.JSON(fiber.Map{
		"success":  true,
		"message":  "获取成功",
		"question": question,
	})
}

// SearchQuestions 搜索题目
func (h *QuestionHandler) SearchQuestions(c *fiber.Ctx) error {
	query := c.Query("query", "")
	qTypeStr := c.Query("type", "0")
	knowledgeTreeIdsStr := c.Query("knowledge_tree_ids", "")
	pageStr := c.Query("page", "1")
	pageSizeStr := c.Query("page_size", "10")

	qType, _ := strconv.ParseInt(qTypeStr, 10, 32)
	page, _ := strconv.ParseInt(pageStr, 10, 32)
	pageSize, _ := strconv.ParseInt(pageSizeStr, 10, 32)

	var knowledgeTreeIds []string
	if knowledgeTreeIdsStr != "" {
		// 逗号分割的知识树ID列表
		knowledgeTreeIds = strings.Split(knowledgeTreeIdsStr, ",")
	}

	questions, total, err := h.questionService.SearchQuestions(
		query,
		question.QuestionType(qType),
		knowledgeTreeIds,
		int32(page),
		int32(pageSize),
	)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	// 如果有 KnowledgeTreeService，则为每道题附加知识树名称，便于前端展示
	if h.knowledgeTreeService != nil {
		// 收集所有题目中出现过的知识树ID（去重）
		idSet := make(map[string]struct{})
		var allIDs []string
		for _, q := range questions {
			for _, id := range q.KnowledgeTreeIDs {
				if id == "" {
					continue
				}
				if _, exists := idSet[id]; !exists {
					idSet[id] = struct{}{}
					allIDs = append(allIDs, id)
				}
			}
		}

		if len(allIDs) > 0 {
			// 批量获取名称（不存在的知识树节点会跳过，不报错）
			idToName, err := h.knowledgeTreeService.GetKnowledgeTreeNames(allIDs)
			if err != nil {
				return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
					"success": false,
					"message": err.Error(),
				})
			}

			// 为每道题填充 KnowledgeTreeNames
			for _, q := range questions {
				q.KnowledgeTreeNames = nil
				for _, id := range q.KnowledgeTreeIDs {
					if name, ok := idToName[id]; ok {
						q.KnowledgeTreeNames = append(q.KnowledgeTreeNames, name)
					}
				}
			}
		}
	}

	return c.JSON(fiber.Map{
		"success":   true,
		"message":   "搜索成功",
		"questions": questions,
		"total":     total,
		"page":      page,
		"page_size": pageSize,
	})
}

// UpdateQuestion 更新题目
func (h *QuestionHandler) UpdateQuestion(c *fiber.Ctx) error {
	var req service.UpdateQuestionRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "请求参数解析失败: " + err.Error(),
		})
	}

	if req.Id == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "题目ID不能为空",
		})
	}

	err := h.questionService.UpdateQuestion(&req)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	return c.JSON(fiber.Map{
		"success": true,
		"message": "更新成功",
	})
}

// DeleteQuestion 删除题目
func (h *QuestionHandler) DeleteQuestion(c *fiber.Ctx) error {
	id := c.Query("id")
	if id == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "题目ID不能为空",
		})
	}

	err := h.questionService.DeleteQuestion(id)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	return c.JSON(fiber.Map{
		"success": true,
		"message": "删除成功",
	})
}

// BatchDeleteQuestions 批量删除题目
func (h *QuestionHandler) BatchDeleteQuestions(c *fiber.Ctx) error {
	var req struct {
		QuestionIds []string `json:"question_ids"`
	}
	if err := c.BodyParser(&req); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "请求参数解析失败: " + err.Error(),
		})
	}

	if len(req.QuestionIds) == 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"message": "题目ID列表不能为空",
		})
	}

	deletedCount, failedIDs, err := h.questionService.BatchDeleteQuestions(req.QuestionIds)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"message": err.Error(),
		})
	}

	return c.JSON(fiber.Map{
		"success":             true,
		"message":             "批量删除完成",
		"deleted_count":       deletedCount,
		"failed_question_ids": failedIDs,
	})
}