import React from 'react'
import {mdiFunctionVariant, mdiTableRowPlusAfter} from '@mdi/js';
import latest from '@maplibre/maplibre-gl-style-spec/dist/latest.json'

import InputButton from './InputButton'
import InputSpec from './InputSpec'
import InputNumber from './InputNumber'
import InputString from './InputString'
import InputSelect from './InputSelect'
import Block from './Block'
import docUid from '../libs/document-uid'
import sortNumerically from '../libs/sort-numerically'
import {findDefaultFromSpec} from '../libs/spec-helper';

import labelFromFieldName from '../libs/label-from-field-name'
import DeleteStopButton from './_DeleteStopButton'



function setStopRefs(props: DataPropertyProps, state: DataPropertyState) {
  // This is initialsed below only if required to improved performance.
  let newRefs: {[key: number]: string} | undefined;

  if(props.value && props.value.stops) {
    props.value.stops.forEach((_val, idx) => {
      if(!Object.prototype.hasOwnProperty.call(state.refs, idx)) {
        if(!newRefs) {
          newRefs = {...state};
        }
        newRefs[idx] = docUid("stop-");
      }
    })
  }

  return newRefs;
}

type DataPropertyProps = {
  onChange?(fieldName: string, value: any): unknown
  onDeleteStop?(...args: unknown[]): unknown
  onAddStop?(...args: unknown[]): unknown
  onExpressionClick?(...args: unknown[]): unknown
  onChangeToZoomFunction?(...args: unknown[]): unknown
  fieldName: string
  fieldType?: string
  fieldSpec?: object
  value?: DataPropertyValue
  errors?: object
};

type DataPropertyState = {
  refs: {[key: number]: string}
};

type DataPropertyValue = {
  default?: any
  property?: string
  base?: number
  type?: string
  stops: Stop[]
}

export type Stop = [{
  zoom: number
  value: number
}, number]

export default class DataProperty extends React.Component<DataPropertyProps, DataPropertyState> {
  state = {
    refs: {} as {[key: number]: string}
  }

  componentDidMount() {
    const newRefs = setStopRefs(this.props, this.state);

    if(newRefs) {
      this.setState({
        refs: newRefs
      })
    }
  }

  static getDerivedStateFromProps(props: DataPropertyProps, state: DataPropertyState) {
    const newRefs = setStopRefs(props, state);
    if(newRefs) {
      return {
        refs: newRefs
      };
    }
    return null;
  }

  getFieldFunctionType(fieldSpec: any) {
    if (fieldSpec.expression.interpolated) {
      return "exponential"
    }
    if (fieldSpec.type === "number") {
      return "interval"
    }
    return "categorical"
  }

  getDataFunctionTypes(fieldSpec: any) {
    if (fieldSpec.expression.interpolated) {
      return ["interpolate", "categorical", "interval", "exponential", "identity"]
    }
    else {
      return ["categorical", "interval", "identity"]
    }
  }

  // Order the stops altering the refs to reflect their new position.
  orderStopsByZoom(stops: Stop[]) {
    const mappedWithRef = stops
      .map((stop, idx) => {
        return {
          ref: this.state.refs[idx],
          data: stop
        }
      })
    // Sort by zoom
      .sort((a, b) => sortNumerically(a.data[0].zoom, b.data[0].zoom));

    // Fetch the new position of the stops
    const newRefs = {} as {[key: number]: string};
    mappedWithRef
      .forEach((stop, idx) =>{
        newRefs[idx] = stop.ref;
      })

    this.setState({
      refs: newRefs
    });

    return mappedWithRef.map((item) => item.data);
  }

  onChange = (fieldName: string, value: any) => {
    if (value.type === "identity") {
      value = {
        type: value.type,
        property: value.property,
      };
    }
    else {
      const stopValue = value.type === 'categorical' ? '' : 0;
      value = {
        property: "",
        type: value.type,
        // Default props if they don't already exist.
        stops: [
          [{zoom: 6, value: stopValue}, findDefaultFromSpec(this.props.fieldSpec as any)],
          [{zoom: 10, value: stopValue}, findDefaultFromSpec(this.props.fieldSpec as any)]
        ],
        ...value,
      }
    }
    this.props.onChange!(fieldName, value);
  }

  changeStop(changeIdx: number, stopData: { zoom: number | undefined, value: number }, value: number) {
    const stops = this.props.value?.stops.slice(0) || []
    // const changedStop = stopData.zoom === undefined ? stopData.value : stopData
    stops[changeIdx] = [
      {
        value: stopData.value,
        zoom: (stopData.zoom === undefined) ? 0 : stopData.zoom,
      },
      value
    ];

    const orderedStops = this.orderStopsByZoom(stops);

    const changedValue = {
      ...this.props.value,
      stops: orderedStops,
    }
    this.onChange(this.props.fieldName, changedValue)
  }

  changeBase(newValue: number | undefined) {
    const changedValue = {
      ...this.props.value,
      base: newValue
    }

    if (changedValue.base === undefined) {
      delete changedValue["base"];
    }
    this.props.onChange!(this.props.fieldName, changedValue)
  }

  changeDataType(propVal: string) {
    if (propVal === "interpolate" && this.props.onChangeToZoomFunction) {
      this.props.onChangeToZoomFunction();
    }
    else {
      this.onChange(this.props.fieldName, {
        ...this.props.value,
        type: propVal,
      });
    }
  }

  changeDataProperty(propName: "property" | "default", propVal: any) {
    if (propVal) {
      this.props.value![propName] = propVal
    }
    else {
      delete this.props.value![propName]
    }
    this.onChange(this.props.fieldName, this.props.value)
  }

  render() {
    if (typeof this.props.value?.type === "undefined") {
      this.props.value!.type = this.getFieldFunctionType(this.props.fieldSpec)
    }

    let dataFields;
    if (this.props.value?.stops) {
      dataFields = this.props.value.stops.map((stop, idx) => {
        const zoomLevel = typeof stop[0] === 'object' ? stop[0].zoom : undefined;
        const key  = this.state.refs[idx];
        const dataLevel = typeof stop[0] === 'object' ? stop[0].value : stop[0];
        const value = stop[1]
        const deleteStopBtn = <DeleteStopButton onClick={this.props.onDeleteStop?.bind(this, idx)} />

        const dataProps = {
          'aria-label': "Input value",
          label: "Data value",
          value: dataLevel as any,
          onChange: (newData: string | number | undefined) => this.changeStop(idx, { zoom: zoomLevel, value: newData as number }, value)
        }

        let dataInput;
        if(this.props.value?.type === "categorical") {
          dataInput = <InputString {...dataProps} />
        }
        else {
          dataInput = <InputNumber {...dataProps} />
        }

        let zoomInput = null;
        if(zoomLevel !== undefined) {
          zoomInput = <div>
            <InputNumber
              aria-label="Zoom"
              value={zoomLevel}
              onChange={newZoom => this.changeStop(idx, {zoom: newZoom, value: dataLevel}, value)}
              min={0}
              max={22}
            />
          </div>
        }

        return <tr key={key}>
          <td>
            {zoomInput}
          </td>
          <td>
            {dataInput}
          </td>
          <td>
            <InputSpec
              aria-label="Output value"
              fieldName={this.props.fieldName}
              fieldSpec={this.props.fieldSpec}
              value={value}
              onChange={(_, newValue) => this.changeStop(idx, {zoom: zoomLevel, value: dataLevel}, newValue as number)}
            />
          </td>
          <td>
            {deleteStopBtn}
          </td>
        </tr>
      })
    }

    return <div className="maputnik-data-spec-block">
      <fieldset className="maputnik-data-spec-property">
        <legend>{labelFromFieldName(this.props.fieldName)}</legend>
        <div className="maputnik-data-fieldset-inner">
          <Block
            label={"Function"}
            key="function"
          >
            <div className="maputnik-data-spec-property-input">
              <InputSelect
                value={this.props.value!.type}
                onChange={(propVal: string) => this.changeDataType(propVal)}
                title={"Select a type of data scale (default is 'categorical')."}
                options={this.getDataFunctionTypes(this.props.fieldSpec)}
              />
            </div>
          </Block>
          {this.props.value?.type !== "identity" &&
            <Block
              label={"Base"}
              key="base"
            >
              <div className="maputnik-data-spec-property-input">
                <InputSpec
                  fieldName={"base"}
                  fieldSpec={latest.function.base as typeof latest.function.base & { type: "number" }}
                  value={this.props.value?.base}
                  onChange={(_, newValue) => this.changeBase(newValue as number)}
                />
              </div>
            </Block>
          }
          <Block
            label={"Property"}
            key="property"
          >
            <div className="maputnik-data-spec-property-input">
              <InputString
                value={this.props.value?.property}
                title={"Input a data property to base styles off of."}
                onChange={propVal => this.changeDataProperty("property", propVal)}
              />
            </div>
          </Block>
          {dataFields &&
            <Block
              label={"Default"}
              key="default"
            >
              <InputSpec
                fieldName={this.props.fieldName}
                fieldSpec={this.props.fieldSpec}
                value={this.props.value?.default}
                onChange={(_, propVal) => this.changeDataProperty("default", propVal)}
              />
            </Block>
          }
          {dataFields &&
            <div className="maputnik-function-stop">
              <table className="maputnik-function-stop-table">
                <caption>Stops</caption>
                <thead>
                  <tr>
                    <th>Zoom</th>
                    <th>Input value</th>
                    <th rowSpan={2}>Output value</th>
                  </tr>
                </thead>
                <tbody>
                  {dataFields}
                </tbody>
              </table>
            </div>
          }
          <div className="maputnik-toolbox">
            {dataFields &&
              <InputButton
                className="maputnik-add-stop"
                onClick={this.props.onAddStop?.bind(this)}
              >
                <svg style={{width:"14px", height:"14px", verticalAlign: "text-bottom"}} viewBox="0 0 24 24">
                  <path fill="currentColor" d={mdiTableRowPlusAfter} />
                </svg> Add stop
              </InputButton>
            }
            <InputButton
              className="maputnik-add-stop"
              onClick={this.props.onExpressionClick?.bind(this)}
            >
              <svg style={{width:"14px", height:"14px", verticalAlign: "text-bottom"}} viewBox="0 0 24 24">
                <path fill="currentColor" d={mdiFunctionVariant} />
              </svg> Convert to expression
            </InputButton>
          </div>
        </div>
      </fieldset>
    </div>
  }
}