import * as React from 'react';
import { useEffect, useState, useRef } from 'react';
import Container from '@mui/material/Container';
import Typography from '@mui/material/Typography';
import Box from '@mui/material/Box';
import FileUploadIcon from '@mui/icons-material/FileUpload';

import {
  DndContext,
  closestCenter,
  KeyboardSensor,
  PointerSensor,
  useSensor,
  useSensors,
  DragOverlay
} from "@dnd-kit/core";
import {
  arrayMove,
  SortableContext,
  sortableKeyboardCoordinates,
  rectSortingStrategy
} from "@dnd-kit/sortable";

import type { DragStartEvent, DragEndEvent, UniqueIdentifier } from "@dnd-kit/core";


import { Module } from './types';

import { modules, steps, module_types, empty_config } from './schema.json';
import {
  Stack,
  Button,
} from '@mui/material';
import Grid from '@mui/material/Grid2';

import { parseDocument, Document, YAMLSeq, YAMLMap, Scalar } from 'yaml'
import StepCard from './StepCard';


function FileDrop({ setYamlFile }: { setYamlFile: React.Dispatch<React.SetStateAction<Document>> }) {

  const [showError, setShowError] = useState(false);
  const [label, setLabel] = useState(<>Drag and drop your orchestration.yaml file here, or click to select a file.</>);
  const wrapperRef = useRef(null);

  function openYAMLFile(event: any) {
    let file = event.target.files[0];
    if (file.type.indexOf('yaml') === -1) {
      setShowError(true);
      setLabel(<>Invalid type, only YAML files are accepted.</>)
      return;
    }
    let reader = new FileReader();
    reader.onload = function (e) {
      let contents = e.target ? e.target.result : '';
      try {
        let document = parseDocument(contents as string);
        if (document.errors.length > 0) {
          // not a valid yaml file
          setShowError(true);
          setLabel(<>Invalid file. Make sure your Orchestration is a valid YAML file with a 'steps' section in it.</>)
          return;
        } else {
          setShowError(false);
          setLabel(<>File loaded successfully.</>)
        }
        // do some basic validation of 'steps'
        let steps = document.get('steps');
        if (!steps) {
          setShowError(true);
          setLabel(<>Invalid file. Your orchestration file must have a 'steps' section in it.</>)
          return;
        }
        const replacements = {
          feeder: 'feeders',
          formatter: 'formatters',
          archivers: 'extractors',
        };

        let error = false;
        for (let stepType of Object.keys(replacements)) {
          if (steps.get(stepType) !== undefined) {
            setShowError(true);
            setLabel(<>Invalid file. Your orchestration file appears to be in the old (v0.12) format with a '{stepType}' section.<br/>You should manually update your orchestration file first (hint: {stepType} → {replacements[stepType]})</>);
            error = true;
            return;
          }
        };
        setYamlFile(document);
      } catch (e) {
        console.error(e);
      }
    }
    reader.readAsText(file);
  }
  return (
    <>
      <div
      style={{
        position: 'relative',
        width: '100%',
        border: 'dashed',
        borderRadius:'5px',
        textAlign: 'center',
        borderWidth: '1px',
        padding: '20px' }}
      onDragEnter={(e) => {
        e.currentTarget.style.backgroundColor = 'var(--mui-palette-LinearProgress-infoBg)';
      }}
      onDragLeave={(e) => {
        e.currentTarget.style.backgroundColor = '';
      }}
      onDrop={(e) => {
        e.currentTarget.style.backgroundColor = '';
      }}
      >
        <FileUploadIcon style={{ fontSize: 50 }} />
        <input style={{
          opacity: 0,
          position: 'absolute',
          top: 0,
          left: 0,
          width: '100%',
          height: '100%',
          cursor: 'pointer',
        }}
        type="file" id="file"
        accept=".yaml"
        onChange={openYAMLFile} />
        <Typography variant="body1" color={showError ? 'error' : ''} >
          {label}
        </Typography>
      </div>
    </>
  );
}

function ModuleTypes({ stepType, setEnabledModules, enabledModules, configValues }: { stepType: string, setEnabledModules: any, enabledModules: any, configValues: any }) {
  const [showError, setShowError] = useState<boolean>(false);
  const [activeId, setActiveId] = useState<UniqueIdentifier>();
  const [items, setItems] = useState<string[]>([]);

  useEffect(() => {
    setItems(enabledModules[stepType].map(([name, enabled]: [string, boolean]) => name));
  }
    , [enabledModules]);

  const toggleModule = (event: any) => {
    // make sure that 'feeder' and 'formatter' types only have one value
    let name = event.target.id;
    let checked = event.target.checked;
    if (stepType === 'feeders' || stepType === 'formatters') {
      // check how many modules of this type are enabled
      const checkedModules = enabledModules[stepType].filter(([m, enabled]: [string, boolean]) => {
        return (m !== name && enabled) || (checked && m === name)
      });
      if (checkedModules.length > 1) {
        setShowError(true);
      } else {
        setShowError(false);
      }
    } else {
      setShowError(false);
    }
    let newEnabledModules = { ...enabledModules };
    newEnabledModules[stepType] = enabledModules[stepType].map(([m, enabled]: [string, boolean]) => {
        return (m === name) ? [m, checked] : [m, enabled];
      });
    setEnabledModules(newEnabledModules);
  }

  const sensors = useSensors(
    useSensor(PointerSensor),
    useSensor(KeyboardSensor, {
      coordinateGetter: sortableKeyboardCoordinates
    })
  );

  const handleDragStart = (event: DragStartEvent) => {
    setActiveId(event.active.id);
  };

  const handleDragEnd = (event: DragEndEvent) => {
    setActiveId(undefined);
    const { active, over } = event;

    if (active.id !== over?.id) {
      const oldIndex = items.indexOf(active.id as string);
      const newIndex = items.indexOf(over?.id as string);

      let newArray = arrayMove(items, oldIndex, newIndex);
      // set it also on steps
      let newEnabledModules = { ...enabledModules };
      newEnabledModules[stepType] = enabledModules[stepType].sort((a, b) => {
        return newArray.indexOf(a[0]) - newArray.indexOf(b[0]);
      })
      setEnabledModules(newEnabledModules);
    }
  };
  return (
    <>
      <Box sx={{ my: 4 }}>
        <Typography id={stepType} variant="h6" style={{ textTransform: 'capitalize' }} >
          {stepType}
        </Typography>
        <Typography variant="body1" >
          Select the <a href={`https://auto-archiver.readthedocs.io/en/latest/modules/${stepType.slice(0,-1)}.html`} target="_blank">{stepType}</a> you wish to enable. Drag to reorder.
        </Typography>
      </Box>
      {showError ? <Typography variant="body1" color="error" >Only one {stepType.slice(0,-1)} can be enabled at a time.</Typography> : null}

      <DndContext
        sensors={sensors}
        collisionDetection={closestCenter}
        onDragEnd={handleDragEnd}
        onDragStart={handleDragStart}
      >
        <Grid container spacing={1} key={stepType}>
          <SortableContext items={items} strategy={rectSortingStrategy}>
            {items.map((name: string) => {
              let m: Module = modules[name];
              return (
                <StepCard key={name} type={stepType} module={m} toggleModule={toggleModule} enabledModules={enabledModules} configValues={configValues} />
              );
            })}
            <DragOverlay>
              {activeId ? (
                <div
                  style={{
                    width: "100%",
                    height: "100%",
                    backgroundColor: "grey",
                    opacity: 0.1,
                  }}
                ></div>

              ) : null}
            </DragOverlay>
          </SortableContext>
        </Grid>
      </DndContext>
    </>
  );
}


export default function App() {
  const [yamlFile, setYamlFile] = useState<Document>(new Document());
  const [enabledModules, setEnabledModules] = useState<{}>(Object.fromEntries(Object.keys(steps).map(type => [type, steps[type].map((name: string) => [name, false])])));
  const [configValues, setConfigValues] = useState<{
    [key: string]: {
      [key: string
      ]: any
    }
  }>(
    Object.keys(modules).reduce((acc, module) => {
      acc[module] = {};
      return acc;
    }, {})
  );

  const saveSettings = function (copy: boolean = false) {
    // edit the yamlFile

    // generate the steps config
    let stepsConfig = enabledModules;

    let finalYamlFile: Document = null;
    if (!yamlFile || yamlFile.contents == null) {
      // create the yaml file from 
      finalYamlFile = parseDocument(empty_config as string);
    } else {
      finalYamlFile = yamlFile;
    }

    // set the steps
    module_types.forEach((type: string) => {
      let stepType = type + 's';
      let existingSteps  = finalYamlFile.getIn(['steps', stepType]) as YAMLSeq;
      stepsConfig[stepType].forEach(([name, enabled]: [string, boolean]) => {
        let index = existingSteps.items.findIndex((item) => { 
          return (item.value || item) === name
        });
        let stepItem = finalYamlFile.getIn(['steps', stepType], true) as YAMLSeq;

        if (enabled && index === -1) {
            finalYamlFile.addIn(['steps', stepType], name);
            stepItem.commentBefore = stepItem.commentBefore?.replace("\n - " + name, '');
            stepItem.comment = stepItem.comment?.replace("\n - " + name, '');
        } else if (!enabled && index !== -1) {
            // set the value to empty and add a comment before with the commented value
            finalYamlFile.deleteIn(['steps', stepType, index]);
            stepItem.commentBefore += "\n - " + name;
            finalYamlFile.setIn(['steps', stepType], stepItem);
        }
      });
      // sort the items
      existingSteps.items.sort((a: Scalar | string, b: Scalar | string) => {
        return (stepsConfig[stepType].findIndex((val: [string, boolean]) => {return val[0] === (a.value || a)}) -
                stepsConfig[stepType].findIndex((val: [string, boolean]) => {return val[0] === (b.value || b)}))
      });
      existingSteps.flow = existingSteps.items.length ? false : true;
    });

    // set all other settings
    // loop through each item that isn't 'steps' in the finalYamlFile and check if it exists in configValues

        Object.keys(configValues).forEach((module_name: string) => {
          // get an existing key
          let existingConfig = finalYamlFile.get(module_name, true) as YAMLMap;
          if (existingConfig) {
            Object.keys(configValues[module_name]).forEach((config_name: string) => {
              let existingConfigYAML = existingConfig.get(config_name, true) as Scalar;
              if (existingConfigYAML) {
                existingConfigYAML.value = configValues[module_name][config_name];
                existingConfig.set(config_name, existingConfigYAML);
              } else {
                existingConfig.set(config_name, configValues[module_name][config_name]);
              }
            });
            finalYamlFile.set(module_name, existingConfig);
          } else {
            if (configValues[module_name] && Object.keys(configValues[module_name]).length > 0) {
              finalYamlFile.set(module_name, configValues[module_name]);
            }
          }
        });

    if (copy) {
      navigator.clipboard.writeText(String(finalYamlFile)).then(() => {
        alert("Settings copied to clipboard.");
      });
    } else {
      // offer the file for download
      const blob = new Blob([String(finalYamlFile)], { type: 'application/x-yaml' });
      const url = URL.createObjectURL(blob);
      const a = document.createElement('a');
      a.href = url;
      a.download = 'orchestration.yaml';
      a.click();
    }
  }

  useEffect(() => {
    // load the configs, and set the default values if they exist
    let newConfigValues = {};
    Object.keys(modules).map((module: string) => {
      let m = modules[module];
      let configs = m.configs;
      if (!configs) {
        return;
      }
      newConfigValues[module] = {};
      Object.keys(configs).map((config: string) => {
        let config_args = configs[config];
        if (config_args.default !== undefined) {
          newConfigValues[module][config] = config_args.default;
        }
      });
    })
    setConfigValues(newConfigValues);
  }, []);

  useEffect(() => {
    if (!yamlFile || yamlFile.contents == null) {
      return;
    }

    let settings = yamlFile.toJS();
    // make a deep copy of settings
    let stepSettings = settings['steps'];
   
    let newEnabledModules = Object.fromEntries(Object.keys(steps).map((type: string) => {
      return [type, steps[type].map((name: string) => {
        return [name, stepSettings[type].indexOf(name) !== -1];
      }).sort((a, b) => {
        let aIndex = stepSettings[type].indexOf(a[0]);
        let bIndex = stepSettings[type].indexOf(b[0]);
        if (aIndex === -1 && bIndex === -1) {
          return a - b;
        }
        if (bIndex === -1) {
          return -1;
        }
        if (aIndex === -1) {
          return 1;
        }
        return aIndex - bIndex;
      })];
    }).sort((a, b) => {
      return module_types.indexOf(a[0]) - module_types.indexOf(b[0]);
    }));
    setEnabledModules(newEnabledModules);

    // set the config values
    let newConfigValues = settings;
    delete newConfigValues['steps'];


    setConfigValues(Object.keys(modules).reduce((acc, module) => {
      acc[module] = newConfigValues[module] || {};
      return acc;
    }, {}));
  }, [yamlFile]);



  return (
    <Container maxWidth="lg">
      <Box sx={{ my: 4 }}>
        <Box sx={{ my: 4 }}>
          <Typography variant="h5" >
            1. Select your orchestration.yaml settings file.
          </Typography>
          <Typography variant="body1">Or skip this step to start from scratch</Typography>
          <FileDrop setYamlFile={setYamlFile} />
        </Box>
        <Box sx={{ my: 4 }}>
          <Typography variant="h5" >
            2. Choose the Modules you wish to enable/disable
          </Typography>
          {Object.keys(steps).map((stepType: string) => {
            return (
              <Box key={stepType} sx={{ my: 4 }}>
                <ModuleTypes stepType={stepType} setEnabledModules={setEnabledModules} enabledModules={enabledModules} configValues={configValues} />
              </Box>
            );
          })}
        </Box>
        <Box sx={{ my: 4 }}>
          <Typography variant="h5" >
            3. Configure your Enabled Modules
          </Typography>
          <Typography variant="body1" >
            Next to each module you've enabled, you can click 'Configure' to set the module's settings.
          </Typography>
        </Box>
        <Box sx={{ my: 4 }}>
          <Typography variant="h5" >
            4. Save your settings
          </Typography>
          <Stack direction="row" spacing={2} sx={{ my: 2 }}>
            <Button variant="contained" color="primary" onClick={() => saveSettings(true)}>Copy Settings to Clipboard</Button>
            <Button variant="contained" color="primary" onClick={() => saveSettings()}>Save Settings to File</Button>
          </Stack>
        </Box>
      </Box>
    </Container>
  );
}