"use client";

import React, { useState, useCallback, useEffect, useRef } from "react";
import {
    AdminPanelConfig,
    AdminPanelState,
    UseAdminPanelOptions,
    UseAdminPanelReturn,
    FieldConfig,
    ValidationRule
} from "@/types/admin-panel";
import { useForm } from "react-hook-form";
import { configFormSchema, ConfigFormValues } from "@/types/config";
import { zodResolver } from "@hookform/resolvers/zod";

// Helper function to get nested value
function getNestedValue(obj: any, path: string): any {
    return path.split('.').reduce((current, key) => current?.[key], obj);
}

// Helper function to set nested value
function setNestedValue(obj: any, path: string, value: any): any {
    const keys = path.split('.');
    const result = { ...obj };
    let current = result;

    for (let i = 0; i < keys.length - 1; i++) {
        const key = keys[i];
        current[key] = current[key] ? { ...current[key] } : {};
        current = current[key];
    }

    current[keys[keys.length - 1]] = value;
    return result;
}

// Helper function to validate a field
function validateField(field: FieldConfig, value: any): string | null {
    if (!field.validation) return null;

    const { validation } = field;

    // Required validation
    if (validation.required && (value === undefined || value === null || value === '')) {
        return `${field.label}是必填项`;
    }

    // Skip other validations if value is empty and not required
    if (value === undefined || value === null || value === '') {
        return null;
    }

    // Min/Max validation for numbers
    if (typeof value === 'number') {
        if (validation.min !== undefined && value < validation.min) {
            return `${field.label}不能小于${validation.min}`;
        }
        if (validation.max !== undefined && value > validation.max) {
            return `${field.label}不能大于${validation.max}`;
        }
    }

    // Length validation for strings
    if (typeof value === 'string') {
        if (validation.minLength !== undefined && value.length < validation.minLength) {
            return `${field.label}长度不能少于${validation.minLength}个字符`;
        }
        if (validation.maxLength !== undefined && value.length > validation.maxLength) {
            return `${field.label}长度不能超过${validation.maxLength}个字符`;
        }
    }

    // Pattern validation
    if (validation.pattern && typeof value === 'string' && !validation.pattern.test(value)) {
        return `${field.label}格式不正确`;
    }

    // Custom validation
    if (validation.custom) {
        return validation.custom(value);
    }

    return null;
}

// Get all fields from config
function getAllFields(config: AdminPanelConfig): FieldConfig[] {
    return config.tabs.flatMap(tab =>
        tab.sections.flatMap(section => section.fields)
    );
}

export function useAdminPanel(options: UseAdminPanelOptions): UseAdminPanelReturn {
    const { config, initialValues = {}, onSubmit } = options;

    // 计算初始值，包含字段默认值
    const computedInitialValues = React.useMemo(() => {
        const fields = getAllFields(config);
        const values: Record<string, any> = { ...initialValues };

        fields.forEach(field => {
            if (getNestedValue(values, field.id) === undefined) {
                setNestedValue(values, field.id, field.value);
            }
        });

        return values;
    }, [config, initialValues]);

    // 使用 react-hook-form 作为唯一的数据源
    const form = useForm<ConfigFormValues>({
        resolver: zodResolver(configFormSchema),
        defaultValues: computedInitialValues,
    });

    // 通过 form.watch() 监听所有表单数据变化
    const values = form.watch();

    // 简化的状态，只保留非表单数据
    const [state, setState] = useState<Omit<AdminPanelState, 'values' | 'dirty'>>({
        errors: {},
        loading: false,
        saving: false,
    });

    // Auto-save timer 和上次保存的值
    const autoSaveTimer = useRef<NodeJS.Timeout | null>(null);
    const lastSavedValues = useRef<Record<string, any>>(computedInitialValues);

    // 使用 form.formState.dirtyFields 来判断字段是否已修改
    const { formState } = form;
    const { dirtyFields } = formState;

    // 重新设置初始值（当配置或初始值变化时）
    useEffect(() => {
        form.reset(computedInitialValues);
        lastSavedValues.current = computedInitialValues;
    }, [computedInitialValues]); // 移除 form 依赖

    // Auto-save 功能
    useEffect(() => {
        if (!config.autoSave || !onSubmit) return;

        const delay = config.autoSaveDelay || 2000;

        if (autoSaveTimer.current) {
            clearTimeout(autoSaveTimer.current);
        }

        // 检查是否有变化
        const hasChanges = JSON.stringify(values) !== JSON.stringify(lastSavedValues.current);
        const hasDirtyFields = Object.keys(dirtyFields).length > 0;

        if (hasChanges && hasDirtyFields) {
            autoSaveTimer.current = setTimeout(async () => {
                try {
                    const currentValues = form.getValues();
                    await onSubmit(currentValues);
                    lastSavedValues.current = currentValues;
                    // 标记所有字段为干净状态，但不改变值
                    form.reset(currentValues, { keepValues: true });
                } catch (error) {
                    console.error('Auto-save failed:', error);
                }
            }, delay);
        }

        return () => {
            if (autoSaveTimer.current) {
                clearTimeout(autoSaveTimer.current);
            }
        };
    }, [values, dirtyFields, config.autoSave, config.autoSaveDelay, onSubmit]); // 移除 form 依赖

    // 缓存字段配置以避免循环依赖
    const fields = React.useMemo(() => getAllFields(config), [config]);
    const validateOnChange = config.validateOnChange;

    // 防抖验证，避免频繁验证
    const validationTimer = useRef<NodeJS.Timeout | null>(null);

    // 执行字段验证的函数
    const performValidation = useCallback(() => {
        const errors: Record<string, string> = {};

        fields.forEach(field => {
            // 跳过禁用或只读字段的验证
            if (field.disabled || field.readOnly) return;

            // 检查条件渲染
            if (field.showWhen && !field.showWhen(values)) return;

            const value = getNestedValue(values, field.id);
            const error = validateField(field, value);
            if (error) {
                errors[field.id] = error;
            }
        });

        setState(prev => ({ ...prev, errors }));
    }, [fields, values]);

    // 初始验证 - 组件挂载时和配置变化时执行一次
    useEffect(() => {
        performValidation();
    }, [fields, computedInitialValues]); // 当字段配置或初始值变化时重新验证

    // 监听值变化进行实时验证
    useEffect(() => {
        if (!validateOnChange) return;

        // 清除之前的验证定时器
        if (validationTimer.current) {
            clearTimeout(validationTimer.current);
        }

        // 延迟验证，避免频繁触发
        validationTimer.current = setTimeout(() => {
            performValidation();
        }, 300); // 300ms 防抖

        return () => {
            if (validationTimer.current) {
                clearTimeout(validationTimer.current);
            }
        };
    }, [values, validateOnChange, performValidation]);

    // Actions - 使用 form 的方法来更新值
    const setValue = useCallback((path: string, value: any) => {
        (form.setValue as any)(path, value, { shouldDirty: true, shouldValidate: validateOnChange });

        // 清除该字段的错误
        setState(prev => {
            const newErrors = { ...prev.errors };
            delete newErrors[path];
            return { ...prev, errors: newErrors };
        });

        // 调用 onChange 回调
        if (config.onValueChange) {
            const currentValues = form.getValues();
            const newValues = setNestedValue(currentValues, path, value);
            config.onValueChange(path, value, newValues);
        }
    }, [form, config.onValueChange, validateOnChange]); // 移除 values 依赖

    const setValues = useCallback((newValues: Record<string, any>) => {
        Object.entries(newValues).forEach(([path, value]) => {
            (form.setValue as any)(path, value, { shouldDirty: true });
        });
    }, [form]);

    const resetValue = useCallback((path: string) => {
        const field = fields.find(f => f.id === path);
        if (field) {
            (form.setValue as any)(path, field.value, { shouldDirty: false });

            // 清除该字段的错误
            setState(prev => {
                const newErrors = { ...prev.errors };
                delete newErrors[path];
                return { ...prev, errors: newErrors };
            });
        }
    }, [fields, form]);

    const resetAll = useCallback(() => {
        form.reset(computedInitialValues);
        setState(prev => ({ ...prev, errors: {} }));
        lastSavedValues.current = computedInitialValues;

        if (config.onReset) {
            config.onReset();
        }
    }, [computedInitialValues, config.onReset, form]);

    const validate = useCallback((): boolean => {
        const currentValues = form.getValues();
        const errors: Record<string, string> = {};

        fields.forEach(field => {
            // 跳过禁用或只读字段的验证
            if (field.disabled || field.readOnly) return;

            // 检查条件渲染
            if (field.showWhen && !field.showWhen(currentValues)) return;

            const value = getNestedValue(currentValues, field.id);
            const error = validateField(field, value);
            if (error) {
                errors[field.id] = error;
            }
        });

        // 自定义验证
        if (config.onValidate) {
            const customErrors = config.onValidate(currentValues);
            Object.assign(errors, customErrors);
        }

        setState(prev => ({ ...prev, errors }));
        return Object.keys(errors).length === 0;
    }, [fields, config.onValidate, form]);

    const save = useCallback(async () => {
        debugger
        if (!onSubmit) return;

        // 验证（如果需要）
        // if (config.validateOnSubmit !== false) {
        //     const isValid = validate();
        //     if (!isValid) return;
        // }

        setState(prev => ({ ...prev, saving: true }));
        const currentValues = form.getValues();

        try {
            await onSubmit(currentValues);
            lastSavedValues.current = currentValues;
            // 标记所有字段为干净状态，但不改变值
            form.reset(currentValues, { keepValues: true });
            setState(prev => ({
                ...prev,
                saving: false,
                errors: {}
            }));

            if (config.onSave) {
                await config.onSave(currentValues);
            }
        } catch (error) {
            setState(prev => ({ ...prev, saving: false }));
            throw error;
        }
    }, [config.validateOnSubmit, config.onSave, onSubmit, validate, form]);

    const clearErrors = useCallback(() => {
        setState(prev => ({ ...prev, errors: {} }));
    }, []);

    // Helpers - 直接使用 form.watch() 的数据
    const getValue = useCallback((path: string) => {
        return getNestedValue(values, path);
    }, [values]);

    const getError = useCallback((path: string) => {
        return state.errors[path] || getNestedValue(form.formState.errors, path)?.message;
    }, [state.errors, form.formState.errors]);

    const isDirty = useCallback((path?: string) => {
        if (path) {
            return Boolean(getNestedValue(dirtyFields, path));
        }
        return Object.keys(dirtyFields).length > 0;
    }, [dirtyFields]);

    const isValid = useCallback((path?: string) => {
        if (path) {
            return !state.errors[path] && !getNestedValue(form.formState.errors, path);
        }
        return Object.keys(state.errors).length === 0 && form.formState.isValid;
    }, [state.errors, form.formState.errors, form.formState.isValid]);

    // 构建返回的状态，包含 values
    const adminPanelState: AdminPanelState = {
        ...state,
        values,
        dirty: dirtyFields,
    };

    return {
        form,
        state: adminPanelState,
        actions: {
            setValue,
            setValues,
            resetValue,
            resetAll,
            save,
            validate,
            clearErrors,
        },
        helpers: {
            getValue,
            getError,
            isDirty,
            isValid,
        },
    };
}