import { DragIndicator, Clear } from "@mui/icons-material";
import {
  Card,
  CardContent,
  CardHeader,
  IconButton,
  Stack,
  TextField,
} from "@mui/material";
import React, { useRef, useState } from "react";
export default function FormBuilder() {
  return (
    <Stack direction={"column"}>
      <h3>FormBuilder</h3>
      <Stack
        direction={"row"}
        justifyContent={"space-between"}
        alignItems={"flex-start"}
        spacing={2}
      >
        <Form initialForm={false} editable />
        <WidgetsLibrary />
      </Stack>
    </Stack>
  );
}

const availableWidgets = {
  label: {
    name: "Label",
    element: (props) => (
      <TextField
        id="outlined-basic"
        variant="standard"
        value={props?.name}
        onChange={(e) =>
          props?.setFormField({ ...props, name: e.target.value })
        }
        fullWidth
      />
    ),
    finalElement: (props) => <div>{props?.id}</div>,
  },
  number: {
    name: "Number",
    element: (props) => (
      <TextField
        id="outlined-basic"
        label={props?.id ? `example field ${props.id}` : "Outlined"}
        variant="outlined"
        type={"number"}
        fullWidth
      />
    ),
  },
  text: {
    name: "Text",
    element: (props) => (
      <TextField
        id="outlined-basic"
        label={props?.id ? `example field ${props.id}` : "Outlined"}
        variant="outlined"
        fullWidth
      />
    ),
  },
  multiline: {
    name: "Multiline",
    element: (props) => (
      <TextField
        id="outlined-textarea"
        label={props?.id ? `example field ${props.id}` : "Multiline"}
        placeholder="Placeholder"
        multiline
        minRows={4}
        fullWidth
      />
    ),
  },
};

function WidgetsLibrary() {
  return (
    <Stack
      direction={"column"}
      spacing={0.5}
      alignItems={"flex-start"}
      sx={{ maxHeight: "100vh", height: "100%", overflow: "scroll" }}
    >
      {Object.keys(availableWidgets).map((k) => {
        const props = availableWidgets[k];
        return <WidgetCard key={k} type={k} {...props} />;
      })}
    </Stack>
  );
}

function WidgetCard({ name, element, type, finalElement }) {
  function onDragStart(e) {
    e.dataTransfer.setData("application/formwidgettype", type);
    e.dataTransfer.effectAllowed = "copy";
    console.log(e);
  }

  const disabledFieldOverlay = {
    pointerEvents: "none",
    background: "#7773",
    zIndex: 10,
  };
  if (!element) {
    return;
  } else {
    return (
      <Card
        draggable
        onDragStart={onDragStart}
        sx={{ cursor: "grab", width: "100%" }}
      >
        <Stack
          direction={"row"}
          justifyContent={"start"}
          alignItems={"center"}
          alignContent={"center"}
        >
          <DragIndicator />
          <div>
            <CardHeader title={name} />
            <CardContent>
              <div style={disabledFieldOverlay}>
                {finalElement ? finalElement() : element()}
              </div>
            </CardContent>
          </div>
        </Stack>
      </Card>
    );
  }
}

function FormField(props) {
  if (!props?.type) {
    console.log("formfield render failed", props);
    return;
  }
  const { element: Element } = availableWidgets[props?.type];
  const dragHandleRef = useRef();
  const [target, setTarget] = useState();
  return (
    <Stack
      direction={"row"}
      sx={{ width: "100%", cursor: "grab" }}
      alignItems={"center"}
      justifyContent={"space-between"}
      draggable
      onMouseDown={(e) => setTarget(e.target)}
      onDragStart={(e) => {
        if (dragHandleRef.current.contains(target)) {
          e.dataTransfer.setData("application/formwidgetid", props?.id);
        } else {
          e.preventDefault();
        }
      }}
    >
      <span ref={dragHandleRef}>
        <DragIndicator />
      </span>
      <Element {...props} />
      <IconButton onClick={() => props?.deleteFormField()}>
        <Clear />
      </IconButton>
    </Stack>
  );
}

function capture(e) {
  e.stopPropagation();
  e.preventDefault();
}

function DropZone({ insertField, index, moveField }) {
  const [dragOver, setDragOver] = useState(false);
  return (
    <span
      style={{
        marginTop: "2px",
        marginBottom: "2px",
        width: "100%",
        color: "transparent",
        background: dragOver ? "#22a9" : "#2221",
        height: dragOver ? "2em" : "4px",
        borderRadius: 8,
      }}
      onDragOver={(e) => capture(e) || setDragOver(true)}
      onDragExit={() => setDragOver(false)}
      onDrop={(e) => {
        e.stopPropagation();
        e.preventDefault();
        setDragOver(false);
        console.log(e);
        if ([...e.dataTransfer.types].includes("application/formwidgettype")) {
          const type = e.dataTransfer.getData("application/formwidgettype");
          insertField({ index, type });
        } else if (
          [...e.dataTransfer.types].includes("application/formwidgetid")
        ) {
          const oldId = e.dataTransfer.getData("application/formwidgetid");
          moveField(oldId, index);
        }
      }}
    />
  );
}

function Form({ initialForm, editable }) {
  const [form, setForm] = useState({ fields: [], ...initialForm });

  function updateFormField(newField) {
    setForm({
      ...form,
      fields: form.fields.map((field) =>
        field?.id === newField.id ? newField : field,
      ),
    });
  }

  function deleteFormField(id) {
    const newForm = {
      ...form,
      fields: form.fields.filter((field) => id !== field?.id),
    };
    console.log("deleteFormField", { id, form, newForm });
    setForm({ ...newForm });
  }
  console.log("render", form.fields);

  function insertField({ index, type }) {
    const id = crypto.randomUUID();
    const newField = {
      id,
      type,
    };
    form?.fields?.splice(index + 1, 0, newField);
    setForm({ ...form });
  }

  function moveField(oldId, newIndex) {
    console.log({ oldId, newIndex });
    const oldIndex = form.fields.findIndex(({ id }) => id === oldId);
    const [oldFormField] = form.fields.splice(oldIndex, 1);
    if (oldIndex > newIndex) {
      newIndex++;
    }
    form.fields.splice(newIndex, 0, oldFormField);
    console.log("newform", form);
    setForm({ ...form });
  }

  if (!editable && !initialForm) {
    return;
    // else if (!initialForm) {
    //   return <FormInitialPrompt />;
    // }
  } else {
    return (
      <Stack sx={{ width: "100%" }}>
        <FormHeader form={form} />
        {editable && (
          <DropZone
            moveField={moveField}
            insertField={insertField}
            index={-1}
          />
        )}
        {form?.fields?.map((props, i) => (
          <Grouping key={props?.id}>
            <FormField
              setFormField={(field) => updateFormField(field)}
              deleteFormField={() => deleteFormField(props.id)}
              {...props}
            />
            {editable && (
              <DropZone
                moveField={moveField}
                insertField={insertField}
                index={i}
              />
            )}
          </Grouping>
        ))}
      </Stack>
    );
  }
}

function FormHeader() {
  return;
}

//function FormInitialPrompt() {
//  return (
//    <div
//      style={{
//        minWidth: "50vh",
//        minHeight: "50vh",
//        background: "#33333333",
//      }}
//    >
//      Drag and drop and field here to get started
//    </div>
//  );
//}
//
function Grouping({ children }) {
  return <>{children}</>;
}