import React, { useContext, Fragment } from 'react'
import { Field, VirtualField, IFieldState } from '@formily/react'
import {
  FormPath,
  isFn,
  isStr,
  isEqual,
  isValid,
  log,
  lowercase
} from '@formily/shared'
import {
  ISchemaFieldProps,
  ISchemaFieldComponentProps,
  ISchemaVirtualFieldComponentProps
} from '../types'
import { Schema } from '../shared/schema'
import {
  FormSchemaContext,
  FormComponentsContext,
  FormExpressionScopeContext,
  SchemaFieldPropsContext
} from '../shared/context'
import { complieExpression } from '../shared/expression'

const computeSchemaState = (draft: IFieldState, prevState: IFieldState) => {
  const schema = new Schema(draft.props)
  const prevSchema = new Schema(prevState.props)
  const currentRequired = schema.getExtendsRequired()
  const prevRequired = prevSchema.getExtendsRequired()
  const currentRules = schema.getExtendsRules()
  const prevRules = prevSchema.getExtendsRules()
  const currentEditable = schema.getExtendsEditable()
  const prevEditable = prevSchema.getExtendsEditable()
  if (isValid(currentRequired) && !isEqual(currentRequired, prevRequired)) {
    draft.required = currentRequired
  }
  if (isValid(currentRules) && !isEqual(currentRules, prevRules)) {
    draft.rules = currentRules
  }
  if (isValid(currentEditable) && !isEqual(currentEditable, prevEditable)) {
    draft.selfEditable = currentEditable
  }
}

export const SchemaField: React.FunctionComponent<ISchemaFieldProps> = (
  props: ISchemaFieldProps
) => {
  const path = FormPath.parse(props.path)
  const formSchema = useContext(FormSchemaContext)
  const fieldSchema = new Schema(props.schema || formSchema.get(path))
  const formRegistry = useContext(FormComponentsContext)
  const expressionScope = useContext(FormExpressionScopeContext)
  const ErrorTipPathStr = path.toString()
  if (!fieldSchema) {
    throw new Error(`Can not found schema node by ${ErrorTipPathStr}.`)
  }
  if (!formRegistry) {
    throw new Error(`Can not found any form components.`)
  }
  const schemaType = fieldSchema.type
  const schemaComponent = fieldSchema.getExtendsComponent()
  const schemaRenderer = fieldSchema.getExtendsRenderer()
  const initialComponent = schemaComponent || schemaType
  const renderField = (
    addtionKey: string | number,
    reactKey?: string | number
  ) => {
    return <SchemaField key={reactKey} path={path.concat(addtionKey)} />
  }
  const getPropsFromInterceptor = (stateProps) => {
    let interceptorProps = {}
    if (isFn(formRegistry.componentPropsInterceptor)) {
      interceptorProps = formRegistry.componentPropsInterceptor(props) || {}
    }
    return {
      ...stateProps,
      ['x-component-props']: {
        ...(stateProps['x-component-props'] || {}),
        ...interceptorProps,
      }
    }
  }

  const renderFieldDelegate = (
    callback: (props: ISchemaFieldComponentProps) => React.ReactElement
  ) => {
    return (
      <Field
        path={path}
        initialValue={complieExpression(fieldSchema.default, expressionScope)}
        props={complieExpression(
          fieldSchema.getSelfProps(),
          expressionScope,
          (key: string) => key == 'x-linkages'
        )}
        dataType={fieldSchema.type}
        triggerType={fieldSchema.getExtendsTriggerType()}
        editable={fieldSchema.getExtendsEditable()}
        visible={complieExpression(
          fieldSchema.getExtendsVisible(),
          expressionScope
        )}
        display={complieExpression(
          fieldSchema.getExtendsDisplay(),
          expressionScope
        )}
        required={complieExpression(
          fieldSchema.getExtendsRequired(),
          expressionScope
        )}
        rules={complieExpression(
          fieldSchema.getExtendsRules(),
          expressionScope
        )}
        computeState={computeSchemaState}
      >
        {({ state, mutators, form }) => {
          const stateProps = getPropsFromInterceptor(state.props)
          const props: ISchemaFieldComponentProps = {
            ...state,
            props: stateProps,
            schema: new Schema(fieldSchema).merge(stateProps),
            form,
            mutators,
            renderField
          }
          return (
            <SchemaFieldPropsContext.Provider value={props}>
              {callback(props)}
            </SchemaFieldPropsContext.Provider>
          )
        }}
      </Field>
    )
  }

  const renderVirtualFieldDelegate = (
    callback: (props: ISchemaVirtualFieldComponentProps) => React.ReactElement
  ) => {
    return (
      <VirtualField
        path={path}
        visible={complieExpression(
          fieldSchema.getExtendsVisible(),
          expressionScope
        )}
        display={complieExpression(
          fieldSchema.getExtendsDisplay(),
          expressionScope
        )}
        props={complieExpression(
          fieldSchema.getSelfProps(),
          expressionScope,
          (key: string) => key == 'x-linkages'
        )}
      >
        {({ state, form }) => {
          const stateProps = getPropsFromInterceptor(state.props)
          const props: ISchemaVirtualFieldComponentProps = {
            ...state,
            props: stateProps,
            schema: new Schema(fieldSchema).merge(stateProps),
            form,
            renderField,
            children: fieldSchema.mapProperties(
              (schema: Schema, key: string) => {
                return (
                  <SchemaField
                    schema={schema}
                    key={key}
                    path={path.concat(key)}
                  />
                )
              }
            )
          }

          return (
            <SchemaFieldPropsContext.Provider value={props}>
              {callback(props)}
            </SchemaFieldPropsContext.Provider>
          )
        }}
      </VirtualField>
    )
  }

  const renderProperties = () => {
    return fieldSchema.mapProperties((schema: Schema, key: string) => {
      const childPath = path.concat(key)
      return (
        <SchemaField
          schema={schema}
          key={childPath.toString()}
          path={childPath}
        />
      )
    })
  }

  if (fieldSchema.isObject() && !schemaComponent) {
    if (path.length == 0 || props.onlyRenderProperties) {
      return <Fragment>{renderProperties()}</Fragment>
    }
    return renderFieldDelegate(props => {
      const renderComponent = () => {
        if (!formRegistry.formItemComponent) {
          log.error(
            `Can not found any component.Its key is ${ErrorTipPathStr}.`
          )
          return null
        }
        return React.createElement(
          formRegistry.formItemComponent,
          props,
          renderProperties()
        )
      }
      if (isFn(schemaRenderer)) {
        return schemaRenderer({ ...props, renderComponent })
      }
      return renderComponent()
    })
  } else {
    if (isStr(initialComponent)) {
      if (formRegistry.fields[initialComponent]) {
        return renderFieldDelegate(props => {
          const stateComponent = lowercase(
            props.schema.getExtendsComponent() || props.schema.type
          )
          if (!isStr(stateComponent)) {
            log.error(
              `Can not found any form component <${stateComponent}>.Its key is ${ErrorTipPathStr}.`
            )
            return null
          }
          const renderComponent = (): React.ReactElement => {
            if (!formRegistry.fields[stateComponent]) {
              log.error(
                `Can not found the field component <${stateComponent}>.Its key is ${ErrorTipPathStr}.`
              )
              return null
            }
            return React.createElement(
              formRegistry.formItemComponent,
              props,
              React.createElement(formRegistry.fields[stateComponent], props)
            )
          }
          if (isFn(schemaRenderer)) {
            return schemaRenderer({ ...props, renderComponent })
          }
          return renderComponent()
        })
      } else if (formRegistry.virtualFields[initialComponent]) {
        return renderVirtualFieldDelegate(props => {
          const stateComponent = lowercase(
            props.schema.getExtendsComponent() || props.schema.type
          )
          if (!isStr(stateComponent)) {
            log.error(
              `Can not found any virtual form component <${stateComponent}>.Its key is ${ErrorTipPathStr}.`
            )
            return null
          }
          const renderComponent = () => {
            if (!formRegistry.virtualFields[stateComponent]) {
              log.error(
                `Can not found the virtual field component <${stateComponent}>.Its key is ${ErrorTipPathStr}.`
              )
              return null
            }
            return React.createElement(
              formRegistry.virtualFields[stateComponent],
              props
            )
          }

          if (isFn(schemaRenderer)) {
            return schemaRenderer({ ...props, renderComponent })
          }
          return renderComponent()
        })
      } else {
        log.error(
          `Can not found the field component <${initialComponent}>.Its key is ${ErrorTipPathStr}.`
        )
        return null
      }
    } else {
      log.error(
        `Can not found the field component <${initialComponent}>.Its key is ${ErrorTipPathStr}.`
      )
      return null
    }
  }
}