package scenario

import (
	"encoding/json"
	"errors"
	"net/http"
	"regexp"
	"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"
	"github.com/google/uuid"
	"gorm.io/datatypes"
	"gorm.io/gorm"
)

type Handler struct {
	db *gorm.DB
}

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

type scenarioInput struct {
	Name         string          `json:"name" binding:"required,max=128"`
	Industry     string          `json:"industry" binding:"required,max=64"`
	RoleName     string          `json:"role_name" binding:"required,max=64"`
	Goal         string          `json:"goal" binding:"required,max=2000"`
	TriggerText  string          `json:"trigger_text" binding:"required,max=2000"`
	Visibility   string          `json:"visibility" binding:"omitempty,oneof=private team tenant"`
	OutputSchema json.RawMessage `json:"output_schema"`
	ResultSchema json.RawMessage `json:"result_schema"`
}

type fieldInput struct {
	FieldKey   string          `json:"field_key" binding:"required,max=64"`
	FieldName  string          `json:"field_name" binding:"required,max=128"`
	SourcePath string          `json:"source_path" binding:"max=255"`
	FieldType  string          `json:"field_type" binding:"required,oneof=text textarea number boolean select multiselect array date"`
	Required   bool            `json:"required"`
	Options    json.RawMessage `json:"options"`
	Validation json.RawMessage `json:"validation"`
	SortOrder  int             `json:"sort_order"`
}

var fieldKeyPattern = regexp.MustCompile(`^[A-Za-z][A-Za-z0-9_]*$`)
var sourcePathPattern = regexp.MustCompile(`^[A-Za-z][A-Za-z0-9_]*(?:\.(?:[A-Za-z][A-Za-z0-9_]*|\*)|\[(?:\d+|\*)\])*$`)

func buildInputSchema(fields []model.ScenarioField) datatypes.JSON {
	items := make([]gin.H, 0, len(fields))
	for _, field := range fields {
		items = append(items, gin.H{"key": field.FieldKey, "name": field.FieldName, "type": field.FieldType, "source_path": field.SourcePath, "required": field.Required, "options": field.Options, "validation": field.Validation})
	}
	raw, _ := json.Marshal(gin.H{"fields": items})
	return datatypes.JSON(raw)
}

func syncInputSchema(tx *gorm.DB, tenantID, scenarioID uint64) error {
	fields := make([]model.ScenarioField, 0)
	if err := tx.Where("tenant_id = ? AND scenario_id = ?", tenantID, scenarioID).Order("sort_order, id").Find(&fields).Error; err != nil {
		return err
	}
	return tx.Model(&model.Scenario{}).Where("id = ? AND tenant_id = ?", scenarioID, tenantID).Update("input_schema", buildInputSchema(fields)).Error
}

func (h *Handler) List(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	items := make([]model.Scenario, 0)
	query := access.ScopeScenarios(h.db.Model(&model.Scenario{}), p, "scenarios").Where("scenarios.status <> ?", "archived")
	if keyword := c.Query("keyword"); keyword != "" {
		query = query.Where("scenarios.name LIKE ? OR scenarios.industry LIKE ?", "%"+keyword+"%", "%"+keyword+"%")
	}
	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}
	var total int64
	if err := query.Count(&total).Error; err != nil {
		response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "查询场景失败")
		return
	}
	if err := query.Order("scenarios.updated_at DESC").Find(&items).Error; err != nil {
		response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "查询场景失败")
		return
	}
	response.OK(c, gin.H{"items": items, "total": total})
}

func (h *Handler) Create(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	var input scenarioInput
	if err := c.ShouldBindJSON(&input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "场景信息不完整")
		return
	}
	visibility := input.Visibility
	if visibility == "" {
		visibility = "tenant"
	}
	item := model.Scenario{TenantID: p.TenantID, ScenarioKey: "scenario-" + uuid.NewString(), PublicKey: "pk_" + uuid.NewString(), AllowedOrigins: datatypes.JSON([]byte(`[]`)), Name: input.Name, Industry: input.Industry, RoleName: input.RoleName, Goal: input.Goal, TriggerText: input.TriggerText, Visibility: visibility, Status: "draft", CreatedBy: p.UserID, InputSchema: datatypes.JSON([]byte(`{"fields":[]}`)), OutputSchema: normalizedJSON(input.OutputSchema, `{"fields":[]}`), ResultSchema: normalizedJSON(input.ResultSchema, `{"fields":[]}`)}
	if err := h.db.Create(&item).Error; err != nil {
		response.Error(c, http.StatusInternalServerError, "CREATE_FAILED", "创建场景失败")
		return
	}
	_ = audit.Record(h.db, p, "create", "scenario", item.ID, input)
	response.Created(c, item)
}

func (h *Handler) Get(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, ok := idParam(c, "id")
	if !ok {
		return
	}
	if !access.CanViewScenario(h.db, p, id) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在")
		return
	}
	var item model.Scenario
	if err := h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&item).Error; err != nil {
		notFound(c, err, "场景不存在")
		return
	}
	fields := make([]model.ScenarioField, 0)
	sops := make([]model.SOP, 0)
	h.db.Where("scenario_id = ? AND tenant_id = ?", id, p.TenantID).Order("sort_order, id").Find(&fields)
	item.InputSchema = buildInputSchema(fields)
	if auth.HasPermission(p, "sop.view") {
		h.db.Where("scenario_id = ? AND tenant_id = ?", id, p.TenantID).Order("updated_at DESC").Find(&sops)
	}
	response.OK(c, gin.H{"scenario": item, "fields": fields, "sops": sops})
}

func (h *Handler) Update(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, ok := idParam(c, "id")
	if !ok {
		return
	}
	if !access.CanEditScenario(h.db, p, id) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在或不可编辑")
		return
	}
	var input scenarioInput
	if err := c.ShouldBindJSON(&input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "场景信息不完整")
		return
	}
	visibility := input.Visibility
	if visibility == "" {
		visibility = "tenant"
	}
	updates := map[string]interface{}{"name": input.Name, "industry": input.Industry, "role_name": input.RoleName, "goal": input.Goal, "trigger_text": input.TriggerText, "visibility": visibility}
	if len(input.OutputSchema) > 0 {
		updates["output_schema"] = normalizedJSON(input.OutputSchema, `{"fields":[]}`)
	}
	if len(input.ResultSchema) > 0 {
		updates["result_schema"] = normalizedJSON(input.ResultSchema, `{"fields":[]}`)
	}
	result := h.db.Model(&model.Scenario{}).Where("id = ? AND tenant_id = ? AND status <> ?", id, p.TenantID, "archived").Updates(updates)
	if result.Error != nil || result.RowsAffected == 0 {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在")
		return
	}
	_ = audit.Record(h.db, p, "update", "scenario", id, input)
	h.Get(c)
}

func (h *Handler) Archive(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, ok := idParam(c, "id")
	if !ok {
		return
	}
	if !access.CanEditScenario(h.db, p, id) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在或不可归档")
		return
	}
	err := h.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Model(&model.SOP{}).Where("scenario_id = ? AND tenant_id = ?", id, p.TenantID).Update("status", "archived").Error; err != nil {
			return err
		}
		return tx.Model(&model.Scenario{}).Where("id = ? AND tenant_id = ?", id, p.TenantID).Update("status", "archived").Error
	})
	if err != nil {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在")
		return
	}
	_ = audit.Record(h.db, p, "archive", "scenario", id, nil)
	response.OK(c, gin.H{"id": id})
}

func (h *Handler) CreateField(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	scenarioID, ok := idParam(c, "id")
	if !ok || !access.CanEditScenario(h.db, p, scenarioID) {
		if ok {
			response.Error(c, http.StatusNotFound, "NOT_FOUND", "场景不存在")
		}
		return
	}
	var input fieldInput
	if err := c.ShouldBindJSON(&input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "字段配置不正确")
		return
	}
	if err := validateFieldInput(input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", err.Error())
		return
	}
	item := model.ScenarioField{TenantID: p.TenantID, ScenarioID: scenarioID, FieldKey: input.FieldKey, FieldName: input.FieldName, SourcePath: input.SourcePath, FieldType: input.FieldType, Required: input.Required, Options: normalizedJSON(input.Options, `[]`), Validation: normalizedJSON(input.Validation, `{}`), SortOrder: input.SortOrder}
	if err := h.db.Create(&item).Error; err != nil {
		response.Error(c, http.StatusConflict, "CREATE_FAILED", "字段标识已存在或配置不正确")
		return
	}
	if err := syncInputSchema(h.db, p.TenantID, scenarioID); err != nil {
		response.Error(c, http.StatusInternalServerError, "SAVE_FAILED", "更新输入契约失败")
		return
	}
	_ = audit.Record(h.db, p, "create", "scenario_field", item.ID, input)
	response.Created(c, item)
}

func (h *Handler) UpdateField(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, ok := idParam(c, "fieldId")
	if !ok {
		return
	}
	var existing model.ScenarioField
	if err := h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&existing).Error; err != nil || !access.CanEditScenario(h.db, p, existing.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "字段不存在或不可编辑")
		return
	}
	if h.fieldReferencedByReleasedSOP(existing.ScenarioID, existing.FieldKey, p.TenantID) {
		response.Error(c, http.StatusConflict, "FIELD_IN_USE", "字段已被当前 SOP 引用，不能修改；请先调整 SOP")
		return
	}
	var input fieldInput
	if err := c.ShouldBindJSON(&input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", "字段配置不正确")
		return
	}
	if err := validateFieldInput(input); err != nil {
		response.Error(c, http.StatusBadRequest, "INVALID_ARGUMENT", err.Error())
		return
	}
	updates := map[string]interface{}{"field_key": input.FieldKey, "field_name": input.FieldName, "source_path": input.SourcePath, "field_type": input.FieldType, "required": input.Required, "options": normalizedJSON(input.Options, `[]`), "validation": normalizedJSON(input.Validation, `{}`), "sort_order": input.SortOrder}
	result := h.db.Model(&model.ScenarioField{}).Where("id = ? AND tenant_id = ?", id, p.TenantID).Updates(updates)
	if result.Error != nil || result.RowsAffected == 0 {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "字段不存在")
		return
	}
	if err := syncInputSchema(h.db, p.TenantID, existing.ScenarioID); err != nil {
		response.Error(c, http.StatusInternalServerError, "SAVE_FAILED", "更新输入契约失败")
		return
	}
	_ = audit.Record(h.db, p, "update", "scenario_field", id, input)
	var item model.ScenarioField
	h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&item)
	response.OK(c, item)
}

func (h *Handler) DeleteField(c *gin.Context) {
	p, _ := auth.PrincipalFromContext(c)
	id, ok := idParam(c, "fieldId")
	if !ok {
		return
	}
	var existing model.ScenarioField
	if err := h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).First(&existing).Error; err != nil || !access.CanEditScenario(h.db, p, existing.ScenarioID) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "字段不存在或不可删除")
		return
	}
	if h.fieldReferencedByReleasedSOP(existing.ScenarioID, existing.FieldKey, p.TenantID) {
		response.Error(c, http.StatusConflict, "FIELD_IN_USE", "字段已被当前 SOP 引用，不能删除")
		return
	}
	result := h.db.Where("id = ? AND tenant_id = ?", id, p.TenantID).Delete(&model.ScenarioField{})
	if result.Error != nil || result.RowsAffected == 0 {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", "字段不存在")
		return
	}
	if err := syncInputSchema(h.db, p.TenantID, existing.ScenarioID); err != nil {
		response.Error(c, http.StatusInternalServerError, "SAVE_FAILED", "更新输入契约失败")
		return
	}
	_ = audit.Record(h.db, p, "delete", "scenario_field", id, gin.H{
		"scenario_id": existing.ScenarioID,
		"field_key":   existing.FieldKey,
		"field_name":  existing.FieldName,
		"source_path": existing.SourcePath,
		"field_type":  existing.FieldType,
		"required":    existing.Required,
		"options":     json.RawMessage(existing.Options),
		"validation":  json.RawMessage(existing.Validation),
		"sort_order":  existing.SortOrder,
	})
	response.OK(c, gin.H{"id": id})
}

func normalizedJSON(value json.RawMessage, fallback string) datatypes.JSON {
	if len(value) == 0 || !json.Valid(value) {
		return datatypes.JSON([]byte(fallback))
	}
	return datatypes.JSON(value)
}

func validateFieldInput(input fieldInput) error {
	if !fieldKeyPattern.MatchString(input.FieldKey) {
		return errors.New("字段标识必须以字母开头，且只能包含字母、数字和下划线")
	}
	if input.SourcePath != "" && !sourcePathPattern.MatchString(input.SourcePath) {
		return errors.New("数据路径格式不正确，例如 customer.name 或 order.items[*].product_id")
	}
	if len(input.Options) > 0 {
		var options []string
		if err := json.Unmarshal(input.Options, &options); err != nil || options == nil {
			return errors.New("字段选项必须是文本数组")
		}
		seen := map[string]bool{}
		for _, option := range options {
			if strings.TrimSpace(option) == "" {
				return errors.New("字段选项不能为空")
			}
			normalized := strings.TrimSpace(option)
			if seen[normalized] {
				return errors.New("字段选项不能重复")
			}
			seen[normalized] = true
		}
		if (input.FieldType == "select" || input.FieldType == "multiselect") && len(options) == 0 {
			return errors.New("单选或多选字段至少需要一个选项")
		}
	} else if input.FieldType == "select" || input.FieldType == "multiselect" {
		return errors.New("单选或多选字段至少需要一个选项")
	}
	if len(input.Validation) > 0 {
		var validation map[string]json.RawMessage
		if err := json.Unmarshal(input.Validation, &validation); err != nil || validation == nil {
			return errors.New("字段校验规则必须是 JSON 对象")
		}
		if err := validateFieldRules(input.FieldType, validation); err != nil {
			return err
		}
	}
	return nil
}

func validateFieldRules(fieldType string, validation map[string]json.RawMessage) error {
	allowed := map[string]bool{}
	switch fieldType {
	case "number":
		allowed["min"], allowed["max"] = true, true
	case "text", "textarea":
		allowed["min_length"], allowed["max_length"] = true, true
	}
	for key := range validation {
		if !allowed[key] {
			return errors.New("当前字段类型不支持校验规则 " + key)
		}
	}
	if fieldType == "number" {
		min, hasMin, err := jsonNumber(validation["min"])
		if err != nil {
			return errors.New("最小值必须是数字")
		}
		max, hasMax, err := jsonNumber(validation["max"])
		if err != nil {
			return errors.New("最大值必须是数字")
		}
		if hasMin && hasMax && min > max {
			return errors.New("最小值不能大于最大值")
		}
	}
	if fieldType == "text" || fieldType == "textarea" {
		min, hasMin, err := jsonInteger(validation["min_length"])
		if err != nil || (hasMin && min < 0) {
			return errors.New("最少字符必须是非负整数")
		}
		max, hasMax, err := jsonInteger(validation["max_length"])
		if err != nil || (hasMax && max < 1) {
			return errors.New("最多字符必须是正整数")
		}
		if hasMin && hasMax && min > max {
			return errors.New("最少字符不能大于最多字符")
		}
	}
	return nil
}

func jsonNumber(raw json.RawMessage) (float64, bool, error) {
	if len(raw) == 0 {
		return 0, false, nil
	}
	var value float64
	err := json.Unmarshal(raw, &value)
	return value, true, err
}

func jsonInteger(raw json.RawMessage) (int, bool, error) {
	if len(raw) == 0 {
		return 0, false, nil
	}
	var value int
	err := json.Unmarshal(raw, &value)
	return value, true, err
}

func idParam(c *gin.Context, key string) (uint64, bool) {
	id, err := strconv.ParseUint(c.Param(key), 10, 64)
	if err != nil || id == 0 {
		response.Error(c, http.StatusBadRequest, "INVALID_ID", "资源 ID 不正确")
		return 0, false
	}
	return id, true
}

func notFound(c *gin.Context, err error, message string) {
	if errors.Is(err, gorm.ErrRecordNotFound) {
		response.Error(c, http.StatusNotFound, "NOT_FOUND", message)
		return
	}
	response.Error(c, http.StatusInternalServerError, "QUERY_FAILED", "查询失败")
}