import { View, StyleSheet, ScrollView, ActivityIndicator } from 'react-native';
import { ThemedView } from '@/components/themed-view';
import { ThemedText } from '@/components/themed-text';
import { RunFormSchema, RunTemplateData, FormFieldSchema } from '@/lib/types/template-run';
import { TextInputField } from './form-fields/text-input';
import { NumberInputField } from './form-fields/number-input';
import { SelectInputField } from './form-fields/select-input';
import { ImageUploadField } from './form-fields/image-upload';
import { ColorInputField } from './form-fields/color-input';
import { useState, useEffect, useCallback, useMemo } from 'react';
import { validateFormSchema } from '@/lib/utils/form-schema-transformer';

interface DynamicFormProps {
  schema: RunFormSchema;
  initialData?: RunTemplateData;
  onDataChange?: (data: RunTemplateData, isValid: boolean) => void;
  onSubmit?: () => void;
}

export function DynamicForm({
  schema,
  initialData = {},
  onDataChange,
  onSubmit
}: DynamicFormProps) {
  const [formData, setFormData] = useState<RunTemplateData>(initialData);
  const [errors, setErrors] = useState<Record<string, string>>({});
  const [isValidating, setIsValidating] = useState(false);
  const [schemaError, setSchemaError] = useState<string | null>(null);

  // 验证schema并初始化默认值
  useEffect(() => {
    setIsValidating(true);
    setSchemaError(null);

    try {
      if (!validateFormSchema(schema)) {
        setSchemaError('表单配置格式不正确');
        return;
      }

      const defaultData: RunTemplateData = {};
      schema.fields.forEach(field => {
        if (field.defaultValue !== undefined) {
          defaultData[field.name] = field.defaultValue;
        }
      });

      const finalInitialData = { ...defaultData, ...initialData };
      setFormData(finalInitialData);

      if (onDataChange) {
        onDataChange(finalInitialData, true);
      }
    } catch (error) {
      console.error('表单初始化失败:', error);
      setSchemaError('表单初始化失败');
    } finally {
      setIsValidating(false);
    }
  }, [schema, initialData]);

  // 验证单个字段
  const validateField = useCallback((field: FormFieldSchema, value: any): string | null => {
    // 检查必填
    if (field.required && (value === undefined || value === null || value === '')) {
      return `${field.label} 是必填项`;
    }

    // 如果值为空且不是必填，则跳过其他验证
    if (value === undefined || value === null || value === '') {
      return null;
    }

    // 根据类型验证
    switch (field.type) {
      case 'text':
      case 'textarea':
        if (typeof value !== 'string') {
          return `${field.label} 必须是文本`;
        }
        if (field.min && value.length < field.min) {
          return `${field.label} 至少需要 ${field.min} 个字符`;
        }
        if (field.max && value.length > field.max) {
          return `${field.label} 最多 ${field.max} 个字符`;
        }
        break;

      case 'number':
        const numValue = Number(value);
        if (isNaN(numValue)) {
          return `${field.label} 必须是数字`;
        }
        if (field.min !== undefined && numValue < field.min) {
          return `${field.label} 不能小于 ${field.min}`;
        }
        if (field.max !== undefined && numValue > field.max) {
          return `${field.label} 不能大于 ${field.max}`;
        }
        break;

      case 'select':
        const isValidOption = field.options?.some(option => option.value === value);
        if (!isValidOption) {
          return `${field.label} 选择了无效的选项`;
        }
        break;

      case 'image':
        if (typeof value !== 'string') {
          return `${field.label} 必须是图片URL`;
        }
        if (value && !value.startsWith('http') && !value.startsWith('file://')) {
          return `${field.label} 必须是有效的图片地址`;
        }
        break;

      case 'color':
        if (typeof value !== 'string') {
          return `${field.label} 必须是颜色值`;
        }
        if (value && !/^#[0-9A-F]{6}$/i.test(value)) {
          return `${field.label} 必须是有效的颜色值 (如 #FF0000)`;
        }
        break;
    }

    return null;
  }, []);

  // 更新表单数据
  const updateField = useCallback((fieldName: string, value: any) => {
    const newFormData = { ...formData, [fieldName]: value };
    setFormData(newFormData);

    // 只验证当前字段
    const field = schema.fields.find(f => f.name === fieldName);
    if (!field) return;

    const fieldError = validateField(field, value);
    const newErrors = { ...errors };

    if (fieldError) {
      newErrors[fieldName] = fieldError;
    } else {
      delete newErrors[fieldName];
    }

    setErrors(newErrors);

    // 通知父组件数据变化
    if (onDataChange) {
      const isValid = Object.keys(newErrors).length === 0;
      onDataChange(newFormData, isValid);
    }
  }, [formData, schema.fields, errors, validateField, onDataChange]);

  // 渲染表单字段
  const renderField = useCallback((field: FormFieldSchema) => {
    const value = formData[field.name];
    const error = errors[field.name];
    const onChange = (newValue: any) => updateField(field.name, newValue);

    switch (field.type) {
      case 'text':
      case 'textarea':
        return <TextInputField key={field.name} field={field} value={value} onChange={onChange} error={error} />;

      case 'number':
        return <NumberInputField key={field.name} field={field} value={value} onChange={onChange} error={error} />;

      case 'select':
        return <SelectInputField key={field.name} field={field} value={value} onChange={onChange} error={error} />;

      case 'image':
        return <ImageUploadField key={field.name} field={field} value={value} onChange={onChange} error={error} />;

      case 'color':
        return <ColorInputField key={field.name} field={field} value={value} onChange={onChange} error={error} />;

      default:
        console.warn(`不支持的表单字段类型: ${field.type}`);
        return null;
    }
  }, [formData, errors, updateField]);

  // 显示加载状态
  if (isValidating) {
    return (
      <View style={styles.loadingContainer}>
        <ActivityIndicator size="large" color="#4ECDC4" />
        <ThemedText style={styles.loadingText}>正在加载表单...</ThemedText>
      </View>
    );
  }

  // 显示schema错误
  if (schemaError) {
    return (
      <View style={styles.errorContainer}>
        <ThemedText style={styles.errorTitle}>表单加载失败</ThemedText>
        <ThemedText style={styles.errorText}>{schemaError}</ThemedText>
        <ThemedText style={styles.errorHint}>
          请稍后重试，或联系技术支持。
        </ThemedText>
      </View>
    );
  }

  return (
    <ScrollView style={styles.container} showsVerticalScrollIndicator={false}>
      <ThemedView style={styles.content}>
        {schema.fields.length === 0 ? (
          <View style={styles.emptyContainer}>
            <ThemedText style={styles.emptyIcon}>📋</ThemedText>
            <ThemedText style={styles.emptyText}>无需配置参数</ThemedText>
            <ThemedText style={styles.emptyDescription}>
              此模板使用默认参数，可以直接开始生成
            </ThemedText>
          </View>
        ) : (
          <>
            <ThemedView style={styles.formHeader}>
              <ThemedText style={styles.formTitle}>请填写以下信息</ThemedText>
              <ThemedText style={styles.formDescription}>
                完善配置信息以获得最佳的生成效果
              </ThemedText>
            </ThemedView>

            {schema.fields.map(field => renderField(field))}

            {Object.keys(errors).length > 0 && (
              <ThemedView style={styles.errorSummary}>
                <ThemedText style={styles.errorSummaryText}>
                  ⚠️ 请修正 {Object.keys(errors).length} 个错误后再提交
                </ThemedText>
                {Object.entries(errors).map(([fieldName, error]) => (
                  <ThemedText key={fieldName} style={styles.errorItem}>
                    • {error}
                  </ThemedText>
                ))}
              </ThemedView>
            )}

            {Object.keys(errors).length === 0 && formData && Object.keys(formData).length > 0 && (
              <ThemedView style={styles.successSummary}>
                <ThemedText style={styles.successText}>
                  ✓ 配置信息完整，可以开始生成
                </ThemedText>
              </ThemedView>
            )}
          </>
        )}
      </ThemedView>
    </ScrollView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  content: {
    padding: 16,
  },
  // 加载状态样式
  loadingContainer: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    paddingVertical: 60,
  },
  loadingText: {
    fontSize: 16,
    marginTop: 16,
    opacity: 0.7,
  },
  // 错误状态样式
  errorContainer: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    padding: 24,
  },
  errorTitle: {
    fontSize: 18,
    fontWeight: '600',
    color: '#FF3B30',
    marginBottom: 8,
  },
  errorText: {
    fontSize: 16,
    textAlign: 'center',
    opacity: 0.8,
    marginBottom: 12,
  },
  errorHint: {
    fontSize: 14,
    textAlign: 'center',
    opacity: 0.6,
  },
  // 空状态样式
  emptyContainer: {
    alignItems: 'center',
    paddingVertical: 40,
  },
  emptyIcon: {
    fontSize: 48,
    marginBottom: 16,
  },
  emptyText: {
    fontSize: 18,
    fontWeight: '500',
    marginBottom: 8,
    opacity: 0.8,
  },
  emptyDescription: {
    fontSize: 14,
    textAlign: 'center',
    opacity: 0.6,
    lineHeight: 20,
  },
  // 表单头部样式
  formHeader: {
    marginBottom: 20,
  },
  formTitle: {
    fontSize: 18,
    fontWeight: '600',
    marginBottom: 4,
  },
  formDescription: {
    fontSize: 14,
    opacity: 0.7,
    lineHeight: 20,
  },
  // 错误总结样式
  errorSummary: {
    backgroundColor: 'rgba(255, 59, 48, 0.1)',
    borderRadius: 12,
    padding: 16,
    marginTop: 20,
    borderLeftWidth: 4,
    borderLeftColor: '#FF3B30',
  },
  errorSummaryText: {
    fontSize: 16,
    fontWeight: '600',
    color: '#FF3B30',
    marginBottom: 8,
  },
  errorItem: {
    fontSize: 14,
    color: '#FF3B30',
    marginBottom: 4,
    opacity: 0.9,
  },
  // 成功状态样式
  successSummary: {
    backgroundColor: 'rgba(52, 199, 89, 0.1)',
    borderRadius: 12,
    padding: 16,
    marginTop: 20,
    borderLeftWidth: 4,
    borderLeftColor: '#34C759',
  },
  successText: {
    fontSize: 16,
    fontWeight: '600',
    color: '#34C759',
  },
});
