import {
    IFieldConfig, IFieldTypeHandler, IShrimpQuery, IShrimpCondition, IShrimpPopulate,
    IPageQuery, IPageResult, ITableCrudProto, ILabel, ShrimpConfig, ShrimpError, ShrimpFieldTypes,
} from "../IShrimpType"
import { Shrimp } from "./Shrimp"
import { ShrimpModule, IShrimpModuleOptions } from "./ShrimpModule"
import type { ShrimpCrud } from "./ShrimpCrud"
import type { RootShrimpPower } from "./ShrimpPower"

/** 内置字段类型处理器 */
export const defaultTypeHandlers: Record<string, IFieldTypeHandler> = {
    [ShrimpFieldTypes.Password]: {
        reqFilter: async (value) => {
            if (typeof value === 'string' && value.length > 0) {
                return Shrimp.passwordHasher.hash(value)
            }
            return value
        },
        resFilter: () => "***",
    },
    [ShrimpFieldTypes.Date]: {
        defaultValue: () => Date.now(),
    },
    [ShrimpFieldTypes.Number]: {
        defaultValue: 0,
    },
    [ShrimpFieldTypes.Boolean]: {
        defaultValue: false,
    },
    [ShrimpFieldTypes.Json]: {
        reqFilter: (value) => {
            if (value == null || value === "") return undefined
            if (typeof value === "string") {
                try {
                    return JSON.parse(value)
                } catch {
                    throw new ShrimpError({ t: 'shrimp.invalidJson' })
                }
            }
            return value
        },
        resFilter: (value) => {
            if (value == null) return value
            if (typeof value === "object") {
                return JSON.stringify(value)
            }
            return value
        },
    },
    [ShrimpFieldTypes.Tab]: {
        // tab 是结构化字段：库里/响应/编辑全程是对象，只在"给人看"的边界(import/export/label)走字符串。
        reqFilter: (value, field) => {
            if (value == null || value === "") return undefined
            if (typeof value === "string") {
                try {
                    return (field.parse ?? JSON.parse)(value)
                } catch {
                    throw new ShrimpError({ t: 'shrimp.invalidJson' })
                }
            }
            return value
        },
        // 本体原样下发对象(不再 stringify)；展示文本走 _label，用 format(给人看,可有损)
        // 第二参是已批量解析的子 relation 名(item.__tabRel[field.key])，让 format 能显示关联名而非 id
        resLabel: (value, field, item) => (field.format ?? JSON.stringify)(value, item?.__tabRel?.[field.key]),
    },
}

export class ShrimpTableModule<T, P extends ITableCrudProto<T> = ITableCrudProto<T>> extends ShrimpModule<P> implements ITableCrudProto<T> {
    fields: IFieldConfig[] = []

    constructor(public parent: Shrimp | ShrimpModule, moduleKey: string, public dataSource: ShrimpCrud<T>, fields?: IFieldConfig[], label?: ILabel, power?: RootShrimpPower, options?: IShrimpModuleOptions) {
        super(parent, moduleKey, label || { t: moduleKey }, power, options)
        if (fields) {
            this.fields = fields
        }
        this.root.crudRegistry.set(moduleKey, dataSource)
    }

    getFields(): IFieldConfig[] {
        return this.fields
    }

    static typeHandlers: Map<string, IFieldTypeHandler> = new Map(Object.entries(defaultTypeHandlers))

    static registerTypeHandler(type: string, handler: IFieldTypeHandler) {
        this.typeHandlers.set(type, handler)
    }

    private getTypeHandler(field: IFieldConfig): IFieldTypeHandler | undefined {
        return ShrimpTableModule.typeHandlers.get(field.type)
    }

    /** 前置验证 */
    private async validateField(field: IFieldConfig, value: any, item: Record<string, any>): Promise<ILabel | null> {
        const isEmpty = value === undefined || value === null || value === '' || (Array.isArray(value) && value.length === 0)

        if (field.required && isEmpty) {
            return field.rules?.find(r => r.required)?.message || { t: 'shrimp.fieldRequired', params: { field: field.label } }
        }

        if (isEmpty) return null

        if (Array.isArray(field.options)) {
            const validValues = new Set(field.options.map(o => o.value))
            const values = field.multiple && Array.isArray(value) ? value : [value]
            for (const v of values) {
                if (!validValues.has(v)) {
                    return field.rules?.find(r => r.message)?.message || { t: 'shrimp.fieldInvalid', params: { field: field.label } }
                }
            }
        }

        // multiple 字段值是数组，类型校验需逐元素进行（与上面 options 校验保持一致）；
        // 非 multiple 则整体校验单值。否则数组会被标量类型分支整体判为类型错误。
        const checkType = (v: any): boolean => {
            switch (field.type) {
                case ShrimpFieldTypes.String: return typeof v === 'string'
                case ShrimpFieldTypes.Number: return typeof v === 'number' && !Number.isNaN(v)
                case ShrimpFieldTypes.Boolean: return typeof v === 'boolean'
                case ShrimpFieldTypes.Date: return typeof v === 'number' || v instanceof Date || !isNaN(Date.parse(v))
                default: return true // 非内置标量类型（relation/json/自定义等）不在此校验
            }
        }
        const typeTargets = field.multiple && Array.isArray(value) ? value : [value]
        for (const v of typeTargets) {
            if (!checkType(v)) return { t: 'shrimp.fieldTypeError', params: { field: field.label } }
        }

        if (field.rules) {
            for (const rule of field.rules) {
                const msg = rule.message || { t: 'shrimp.fieldInvalid', params: { field: field.label } }

                if (rule.min !== undefined) {
                    if (typeof value === 'number' && value < rule.min) return { t: 'shrimp.fieldMin', params: { field: field.label, min: rule.min } }
                    if (typeof value === 'string' && value.length < rule.min) return { t: 'shrimp.fieldMinLength', params: { field: field.label, min: rule.min } }
                    if (Array.isArray(value) && value.length < rule.min) return { t: 'shrimp.fieldMinLength', params: { field: field.label, min: rule.min } }
                }

                if (rule.max !== undefined) {
                    if (typeof value === 'number' && value > rule.max) return { t: 'shrimp.fieldMax', params: { field: field.label, max: rule.max } }
                    if (typeof value === 'string' && value.length > rule.max) return { t: 'shrimp.fieldMaxLength', params: { field: field.label, max: rule.max } }
                    if (Array.isArray(value) && value.length > rule.max) return { t: 'shrimp.fieldMaxLength', params: { field: field.label, max: rule.max } }
                }

                if (rule.pattern) {
                    const regex = new RegExp(rule.pattern)
                    if (!regex.test(String(value))) return msg
                }
            }
        }

        return null
    }

    private async prepareAddItem(item: Record<string, any>): Promise<Record<string, any>> {
        const result = { ...item }
        for (const field of this.fields) {
            if (field.editable === "readonly") {
                delete result[field.key]
                continue
            }

            const handler = this.getTypeHandler(field)

            if (result[field.key] === undefined) {
                const dv = field.defaultValue !== undefined ? field.defaultValue : handler?.defaultValue
                if (dv !== undefined) {
                    result[field.key] = typeof dv === 'function' ? (dv as () => any)() : dv
                }
            }

            if (handler?.reqFilter && result[field.key] !== undefined) {
                result[field.key] = await handler.reqFilter(result[field.key], field, result)
            }

            const fieldErr = await this.validateField(field, result[field.key], result)
            if (fieldErr) throw new ShrimpError(fieldErr)

            if (handler?.validate && result[field.key] !== undefined) {
                const err = await handler.validate(result[field.key], field, result)
                if (err) throw new ShrimpError(err)
            }
        }
        return result
    }

    private async prepareEditItem(item: Record<string, any>): Promise<Record<string, any>> {
        const result = { ...item }
        for (const field of this.fields) {
            if (field.editable === "readonly" || field.editable === "addOnly") {
                delete result[field.key]
                continue
            }

            if (result[field.key] === undefined) {
                delete result[field.key]
                continue
            }

            const handler = this.getTypeHandler(field)

            if (handler?.reqFilter) {
                result[field.key] = await handler.reqFilter(result[field.key], field, result)
            }

            const fieldErr = await this.validateField(field, result[field.key], result)
            if (fieldErr) throw new ShrimpError(fieldErr)

            if (handler?.validate) {
                const err = await handler.validate(result[field.key], field, result)
                if (err) throw new ShrimpError(err)
            }
        }
        return result
    }

    private async processResItem(item: Record<string, any>): Promise<Record<string, any>> {
        const result = { ...item }
        for (const field of this.fields) {
            const handler = this.getTypeHandler(field)
            if (handler?.resFilter && result[field.key] !== undefined) {
                result[field.key] = await handler.resFilter(result[field.key], field, result)
            }
            if (handler?.resLabel && result[field.key] !== undefined) {
                result[`${field.key}_label`] = handler.resLabel(result[field.key], field, result)
            }
        }
        delete result.__tabRel // 临时挂的子 relation 解析结果，不下发
        return result
    }

    private async prepareResponseItems(items: any[]): Promise<any[]> {
        if (items.length === 0) return items
        const populates = this.getRelationPopulates()
        if (populates.length > 0 && this.dataSource.populateItems) {
            await this.dataSource.populateItems(items, populates, this.root.crudRegistry)
        }
        await this.populateTabRelations(items)
        return Promise.all(items.map(item => this.processResItem(item)))
    }

    private async prepareResponseItem(item: any): Promise<any> {
        if (!item) return item
        const populates = this.getRelationPopulates()
        if (populates.length > 0 && this.dataSource.populateItems) {
            await this.dataSource.populateItems([item], populates, this.root.crudRegistry)
        }
        await this.populateTabRelations([item])
        return this.processResItem(item)
    }

    /**
     * 解析 tab 字段里 relation 子字段的名字，批量(每个关联模块一次 $in)，
     * 挂到 item.__tabRel[fieldKey][childKey]，供该字段的 format 第二参使用。
     * 不污染 tab 本体对象(避免回灌进库)，__tabRel 在 processResItem 末尾删除。
     */
    private async populateTabRelations(items: any[]): Promise<void> {
        const tabFields = this.fields.filter(f => f.type === ShrimpFieldTypes.Tab && Array.isArray(f.tabs))
        if (tabFields.length === 0 || items.length === 0) return

        const need = new Map<string, { labelKey: string; ids: Set<string> }>()
        const refs: { item: any; fieldKey: string; childKey: string; moduleKey: string; multiple: boolean }[] = []
        for (const item of items) {
            for (const tf of tabFields) {
                const val = item[tf.key]
                if (!val || typeof val !== "object") continue
                const tab = tf.tabs!.find(t => t.key === val.type)
                if (!tab) continue
                for (const child of tab.fields) {
                    if (child.type !== ShrimpFieldTypes.Relation || !child.relation || val[child.key] == null) continue
                    const { moduleKey, labelKey } = child.relation
                    let bucket = need.get(moduleKey)
                    if (!bucket) need.set(moduleKey, (bucket = { labelKey, ids: new Set() }))
                    const cv = val[child.key]
                    ;(Array.isArray(cv) ? cv : [cv]).forEach((id: any) => id != null && bucket!.ids.add(String(id)))
                    refs.push({ item, fieldKey: tf.key, childKey: child.key, moduleKey, multiple: !!child.multiple })
                }
            }
        }
        if (refs.length === 0) return

        const labelMaps = new Map<string, Map<string, any>>()
        for (const [moduleKey, b] of need) {
            const m = new Map<string, any>()
            const crud = this.root.crudRegistry.get(moduleKey)
            if (crud && b.ids.size > 0) {
                const res = await crud.list({ where: { _id: { in: Array.from(b.ids) } }, limit: b.ids.size })
                for (const doc of res.list as any[]) m.set(String(doc._id), doc[b.labelKey])
            }
            labelMaps.set(moduleKey, m)
        }

        for (const ref of refs) {
            const m = labelMaps.get(ref.moduleKey)!
            const cv = ref.item[ref.fieldKey][ref.childKey]
            const label = ref.multiple
                ? (Array.isArray(cv) ? cv.map((id: any) => m.get(String(id)) ?? null) : [])
                : m.get(String(cv)) ?? null
            const bag = (ref.item.__tabRel ||= {})
            ;(bag[ref.fieldKey] ||= {})[ref.childKey] = label
        }
    }

    private excludeKeys(item: any, keys: string[]): any {
        if (keys.length === 0) return item
        const result = { ...item }
        for (const key of keys) {
            delete result[key]
        }
        return result
    }

    private filterHidden(item: any): any {
        return this.excludeKeys(item, this.fields.filter(f => f.hidden).map(f => f.key))
    }

    private getRelationFields(): IFieldConfig[] {
        return this.fields.filter(f => f.type === "relation" && f.relation)
    }

    private getRelationPopulates(): IShrimpPopulate[] {
        return this.getRelationFields().map(f => ({
            key: f.key,
            moduleKey: f.relation!.moduleKey,
            labelKey: f.relation!.labelKey,
        }))
    }

    private buildQuery(query?: IPageQuery & any): IShrimpQuery {
        const { keyword, page, pageSize, sortBy, sortOrder, filter, ownerId } = query || {}
        const p = page || 1
        const ps = pageSize || ShrimpConfig.defaultPageSize
        const shrimpQuery: IShrimpQuery = {
            offset: (p - 1) * ps,
            limit: ps,
        }

        if (filter && typeof filter === 'object') {
            const filterableFields = new Map(this.fields.filter(f => f.filterable).map(f => [f.key, f]))
            const stringLikeTypes = new Set(['string', 'textarea'])
            const where: Record<string, IShrimpCondition> = {}
            for (const [key, value] of Object.entries(filter)) {
                const field = filterableFields.get(key)
                if (!field) continue
                if (value == null) continue
                if (Array.isArray(value) && value.length === 0) continue
                if (typeof value === 'string' && value === '') continue
                const obj = value as any
                if (typeof obj === 'object' && !Array.isArray(obj) && obj.min === undefined && obj.max === undefined) continue

                if (Array.isArray(value)) {
                    where[key] = { in: value }
                } else if (typeof value === 'object') {
                    const cond: IShrimpCondition = {}
                    if (obj.min !== undefined) cond.gte = obj.min
                    if (obj.max !== undefined) cond.lte = obj.max
                    where[key] = cond
                } else if (typeof value === 'boolean') {
                    where[key] = { eq: value }
                } else if (typeof value === 'string' && stringLikeTypes.has(field.type)) {
                    where[key] = { like: value }
                } else {
                    where[key] = { eq: value }
                }
            }
            if (Object.keys(where).length > 0) shrimpQuery.where = where
        }

        // 子表场景: ownerId + ownerKey 强制注入过滤
        if (ownerId != null && ownerId !== '' && this.ownerKey) {
            shrimpQuery.where = shrimpQuery.where || {}
            shrimpQuery.where[this.ownerKey] = { eq: ownerId }
        }

        if (keyword) {
            const stringLikeTypes = new Set(['string', 'textarea'])
            const searchFields = this.fields
                .filter(f => f.searchable && stringLikeTypes.has(f.type))
                .map(f => f.key)
            if (searchFields.length > 0) {
                shrimpQuery.orWhere = searchFields.map(key => ({ [key]: { like: keyword } }))
            }
        }

        if (sortBy) {
            shrimpQuery.order = [[sortBy, sortOrder === 'desc' ? 'desc' : 'asc']]
        }

        return shrimpQuery
    }

    async list(query?: IPageQuery & any): Promise<IPageResult<T>> {
        const shrimpQuery = this.buildQuery(query)
        const result = await this.dataSource.list(shrimpQuery)
        result.list = await this.prepareResponseItems(result.list)
        result.list = result.list.map(item => this.filterHidden(item))
        return result
    }

    async get(id: string): Promise<T | null> {
        const item = await this.dataSource.get(id)
        if (item) {
            const processed = await this.prepareResponseItem(item)
            return this.filterHidden(processed) as T
        }
        return item
    }

    async add(item: Omit<T, '_id'>, ownerId?: string): Promise<T> {
        if (ownerId && this.ownerKey) {
            (item as any)[this.ownerKey] = ownerId
        }
        const prepared = await this.prepareAddItem(item as any)
        const result = await this.dataSource.add(prepared as Omit<T, '_id'>)
        const processed = await this.prepareResponseItem(result)
        return this.filterHidden(processed) as T
    }
    async edit(id: string, item: Partial<T>): Promise<T | null> {
        const prepared = await this.prepareEditItem(item as any)
        const result = await this.dataSource.edit(id, prepared as Partial<T>)
        if (result) {
            const processed = await this.prepareResponseItem(result)
            return this.filterHidden(processed) as T
        }
        return result
    }
    async delete(id: string): Promise<boolean> {
        return await this.dataSource.delete(id)
    }
    async clear(query?: IPageQuery & any): Promise<boolean> {
        const hasFilter = query && (
            (query.keyword) ||
            (query.filter && typeof query.filter === 'object' && Object.keys(query.filter).length > 0)
        )
        if (hasFilter) {
            const shrimpQuery = this.buildQuery(query)
            delete shrimpQuery.offset
            delete shrimpQuery.limit
            const result = await this.dataSource.list(shrimpQuery)
            for (const item of result.list as any[]) {
                await this.dataSource.delete(item._id)
            }
            return true
        }
        return await this.dataSource.clear()
    }
    async export(query?: IPageQuery & any): Promise<T[]> {
        const shrimpQuery = this.buildQuery(query)
        delete shrimpQuery.offset
        delete shrimpQuery.limit
        const result = await this.dataSource.list(shrimpQuery)
        result.list = await this.prepareResponseItems(result.list)
        // 导出是机器往返的边界：结构化字段(如 tab)用可逆的 stringify 序列化(默认 JSON)，
        // import 端的 reqFilter(parse) 能原样还原；展示用的 _label 不进导出，去掉。
        const labelFields = this.fields.filter(f => this.getTypeHandler(f)?.resLabel)
        return result.list.map(item => {
            const row = this.filterHidden(item)
            for (const f of labelFields) {
                if (row[f.key] !== undefined && typeof row[f.key] === "object") {
                    row[f.key] = (f.stringify ?? JSON.stringify)(row[f.key])
                }
                delete row[`${f.key}_label`]
            }
            return row
        })
    }
    async import(data?: T[], ownerId?: string): Promise<void> {
        if (!data || data.length === 0) return
        for (const raw of data) {
            const item = { ...raw } as Record<string, any>
            if (ownerId && this.ownerKey) item[this.ownerKey] = ownerId
            const id = item._id ? String(item._id) : undefined
            if (id) {
                const existing = await this.dataSource.get(id)
                if (existing) {
                    const prepared = await this.prepareEditItem(item)
                    await this.dataSource.edit(id, prepared as Partial<T>)
                    continue
                }
            }
            const prepared = await this.prepareAddItem(item)
            await this.dataSource.add(prepared as Omit<T, '_id'>)
        }
    }

    initCrud() {
        return this
            .addEvent("list", this.power)
            .addEvent("get", this.power)
            .addEvent("add", { t: "power.add" })
            .addEvent("edit", { t: "power.edit" })
            .addEvent("delete", { t: "power.delete" })
    }
}