package knowledge

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"
	"strings"

	"git.iwork-ai.com/xdc/iqudo-top1/internal/access"
	"git.iwork-ai.com/xdc/iqudo-top1/internal/audit"
	"git.iwork-ai.com/xdc/iqudo-top1/internal/auth"
	"git.iwork-ai.com/xdc/iqudo-top1/internal/model"
	"git.iwork-ai.com/xdc/iqudo-top1/internal/response"
	"github.com/gin-gonic/gin"
	"gorm.io/datatypes"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

type Handler struct{ db *gorm.DB }

func NewHandler(db *gorm.DB) *Handler { return &Handler{db: db} }

type input struct {
	ScenarioID uint64                 `json:"scenario_id" binding:"required"`
	Title      string                 `json:"title" binding:"required,max=128"`
	Content    map[string]interface{} `json:"content" binding:"required"`
}

type updateInput struct {
	Title   string                 `json:"title" binding:"required,max=128"`
	Content map[string]interface{} `json:"content" binding:"required"`
}

func (h *Handler) List(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	type row struct {
		model.KnowledgeCard
		Content datatypes.JSON `json:"content"`
		Version int            `json:"version"`
	}
	items := make([]row, 0)
	query := h.db.Table("knowledge_cards kc").Select("kc.*, kcv.content, kcv.version").Joins("JOIN scenarios sc ON sc.id = kc.scenario_id").Joins("LEFT JOIN knowledge_card_versions kcv ON kcv.knowledge_card_id = kc.id AND kcv.status = ?", "published")
	query = access.ScopeScenarios(query, p, "sc")
	err := query.Where("kc.tenant_id = ? AND kc.status <> ? AND sc.status <> ?", p.TenantID, "archived", "archived").Order("kc.updated_at DESC").Scan(&items).Error
	if err != nil {
		response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "查询知识卡失败")
		return
	}
	response.OK(c, gin.H{"items": items, "total": len(items)})
}

func (h *Handler) Update(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil || id == 0 {
		response.Error(c, http.StatusBadRequest, "INVALID_ID", "知识卡 ID 不正确")
		return
	}
	var body updateInput
	if err := c.ShouldBindJSON(&body); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "知识卡内容不完整")
		return
	}
	if err := validateContent(body.Content); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", err.Error())
		return
	}
	content, err := json.Marshal(body.Content)
	if err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "知识卡内容格式不正确")
		return
	}
	var card model.KnowledgeCard
	if err := h.db.Where("id = ? AND tenant_id = ? AND status <> ?", id, p.TenantID, "archived").First(&card).Error; err != nil || !access.CanEditScenario(h.db, p, card.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "知识卡不存在或不可编辑")
		return
	}
	var version model.KnowledgeCardVersion
	err = h.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&card).Error; err != nil {
			return err
		}
		var maxVersion int
		if err := tx.Model(&model.KnowledgeCardVersion{}).Where("knowledge_card_id = ? AND tenant_id = ?", id, p.TenantID).Select("COALESCE(MAX(version), 0)").Scan(&maxVersion).Error; err != nil {
			return err
		}
		if err := tx.Model(&model.KnowledgeCardVersion{}).Where("knowledge_card_id = ? AND tenant_id = ? AND status = ?", id, p.TenantID, "published").Update("status", "superseded").Error; err != nil {
			return err
		}
		version = model.KnowledgeCardVersion{TenantID: p.TenantID, KnowledgeCardID: id, Version: maxVersion + 1, Content: datatypes.JSON(content), Status: "published"}
		if err := tx.Create(&version).Error; err != nil {
			return err
		}
		return tx.Model(&card).Updates(map[string]interface{}{"title": body.Title, "status": "published"}).Error
	})
	if err != nil {
		response.Error(c, http.StatusInternalServerError, "UPDATE_FAILED", "更新知识卡失败")
		return
	}
	_ = audit.Record(h.db, p, "update", "knowledge_card", id, gin.H{"version": version.Version})
	response.OK(c, gin.H{"id": id, "title": body.Title, "version": version.Version, "content": datatypes.JSON(content)})
}

func (h *Handler) Versions(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil || id == 0 {
		response.Error(c, http.StatusBadRequest, "INVALID_ID", "知识卡 ID 不正确")
		return
	}
	var card model.KnowledgeCard
	if err := h.db.Where("id = ? AND tenant_id = ? AND status <> ?", id, p.TenantID, "archived").First(&card).Error; err != nil || !access.CanViewScenario(h.db, p, card.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "知识卡不存在")
		return
	}
	items := make([]model.KnowledgeCardVersion, 0)
	if err := h.db.Where("knowledge_card_id = ? AND tenant_id = ?", id, p.TenantID).Order("version DESC").Find(&items).Error; err != nil {
		response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "查询知识卡版本失败")
		return
	}
	response.OK(c, gin.H{"items": items, "total": len(items)})
}

func (h *Handler) Create(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	var body input
	if err := c.ShouldBindJSON(&body); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "知识卡内容不完整")
		return
	}
	if err := validateContent(body.Content); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", err.Error())
		return
	}
	if !access.CanEditScenario(h.db, p, body.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在或不可编辑")
		return
	}
	content, _ := json.Marshal(body.Content)
	var card model.KnowledgeCard
	err := h.db.Transaction(func(tx *gorm.DB) error {
		card = model.KnowledgeCard{TenantID: p.TenantID, ScenarioID: body.ScenarioID, Title: body.Title, Status: "published", CreatedBy: p.UserID}
		if err := tx.Create(&card).Error; err != nil {
			return err
		}
		return tx.Create(&model.KnowledgeCardVersion{TenantID: p.TenantID, KnowledgeCardID: card.ID, Version: 1, Content: datatypes.JSON(content), Status: "published"}).Error
	})
	if err != nil {
		response.Error(c, http.StatusInternalServerError, "CREATE_FAILED", "创建知识卡失败")
		return
	}
	_ = audit.Record(h.db, p, "create", "knowledge_card", card.ID, body)
	response.Created(c, card)
}

func (h *Handler) Delete(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ID", "知识卡 ID 不正确")
		return
	}
	var card model.KnowledgeCard
	if err := h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&card).Error; err != nil || !access.CanEditScenario(h.db, p, card.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "知识卡不存在或不可归档")
		return
	}
	var references int64
	err = h.db.Table("sop_nodes n").Joins("JOIN sop_versions sv ON sv.id = n.sop_version_id").Joins("JOIN sops s ON s.id = sv.sop_id").Where(
		"n.tenant_id = ? AND s.scenario_id = ? AND sv.status IN ? AND n.type = ? AND JSON_UNQUOTE(JSON_EXTRACT(n.config, '$.knowledge_card_id')) = ?",
		p.TenantID, card.ScenarioID, []string{"published", "offline", "superseded"}, "knowledge", strconv.FormatUint(id, 10),
	).Count(&references).Error
	if err != nil {
		response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "检查知识卡引用失败")
		return
	}
	if references > 0 {
		response.Error(c, http.StatusConflict, "KNOWLEDGE_IN_USE", "知识卡已被发布版本引用，不能归档")
		return
	}
	result := h.db.Model(&model.KnowledgeCard{}).Where("id = ? AND tenant_id = ?", id, p.TenantID).Update("status", "archived")
	if result.Error != nil || result.RowsAffected == 0 {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "知识卡不存在")
		return
	}
	_ = audit.Record(h.db, p, "archive", "knowledge_card", id, nil)
	response.OK(c, gin.H{"id": id})
}

func validateContent(content map[string]interface{}) error {
	standard, ok := content["standard_copy"].(string)
	if !ok || strings.TrimSpace(standard) == "" {
		return errors.New("请填写标准话术")
	}
	for _, key := range []string{"forbidden_copy", "risk_note"} {
		if value, exists := content[key]; exists {
			if _, ok := value.(string); !ok {
				return errors.New("知识卡文本字段格式不正确")
			}
		}
	}
	return nil
}