'use strict';

import React, {Component} from "react";
import PropTypes from "prop-types";
import {withTranslation} from '../../lib/i18n';
import {LinkButton, requiresAuthenticatedUser, Title, Toolbar, withPageHelpers} from "../../lib/page";
import {
    ButtonRow,
    Dropdown,
    filterData,
    Form,
    FormSendMethod,
    InputField,
    withForm,
    withFormErrorHandlers
} from "../../lib/form";
import {withErrorHandling} from "../../lib/error-handling";
import {DeleteModalDialog} from "../../lib/modals";

import styles from "./CUD.scss";
import { DndProvider } from 'react-dnd';
import HTML5Backend from "react-dnd-html5-backend";
import TouchBackend from "react-dnd-touch-backend";
import SortableTree from "react-sortable-tree";
import 'react-sortable-tree/style.css';
import {ActionLink, Button, Icon} from "../../lib/bootstrap-components";
import {getRuleHelpers} from "./helpers";
import RuleSettingsPane from "./RuleSettingsPane";
import {withComponentMixins} from "../../lib/decorator-helpers";
import clone from "clone";

// https://stackoverflow.com/a/4819886/1601953
const isTouchDevice = !!('ontouchstart' in window || navigator.maxTouchPoints);

@withComponentMixins([
    withTranslation,
    withForm,
    withErrorHandling,
    withPageHelpers,
    requiresAuthenticatedUser
])
export default class CUD extends Component {
    // The code below keeps the segment settings in form value. However, it uses it as a mutable datastructure.
    // After initilization, segment settings is never set using setState. This is OK since we update the state.rulesTree
    // from the segment settings on relevant events (changes in the tree and closing the rule settings pane).

    constructor(props) {
        super(props);

        this.ruleHelpers = getRuleHelpers(props.t, props.fields);

        this.state = {
            rulesTree: this.getTreeFromRules([])
            // There is no ruleOptionsVisible here. We have 3 state logic for the visibility:
            //   Undef - not shown, True - shown with entry animation, False - hidden with exit animation
        };

        this.initForm();

        this.onRuleSettingsPaneUpdatedHandler = ::this.onRuleSettingsPaneUpdated;
        this.onRuleSettingsPaneCloseHandler = ::this.onRuleSettingsPaneClose;
        this.onRuleSettingsPaneDeleteHandler = ::this.onRuleSettingsPaneDelete;
    }

    static propTypes = {
        action: PropTypes.string.isRequired,
        list: PropTypes.object,
        fields: PropTypes.array,
        entity: PropTypes.object
    }

    getRulesFromTree(tree) {
        const rules = [];

        for (const node of tree) {
            const rule = node.rule;

            if (this.ruleHelpers.isCompositeRuleType(rule.type)) {
                rule.rules = this.getRulesFromTree(node.children);
            }

            rules.push(rule);
        }

        return rules;
    }

    getTreeFromRules(rules) {
        const ruleHelpers = this.ruleHelpers;

        const tree = [];
        for (const rule of rules) {
            const ruleTreeLabel = ruleHelpers.getTreeLabel(rule);
            const title = ruleTreeLabel ||  this.props.t('newRule');

            tree.push({
                rule,
                title,
                expanded: true,
                children: this.getTreeFromRules(rule.rules || [])
            });
        }

        return tree;
    }

    getFormValuesMutator(data, originalData) {
        data.rootRuleType = data.settings.rootRule.type;
        data.selectedRule = (originalData && originalData.selectedRule) || null; // Validation errors of the selected rule are attached to this which makes sure we don't submit the segment if the opened rule has errors

        this.setState({
            rulesTree: this.getTreeFromRules(data.settings.rootRule.rules)
        });
    }

    submitFormValuesMutator(data) {
        data.settings.rootRule.type = data.rootRuleType;

        // We have to clone the data here otherwise the form change detection doesn't work. This is because we use the state as a mutable structure.
        data = clone(data);

        return filterData(data, ['name', 'settings']);
    }

    componentDidMount() {
        if (this.props.entity) {
            this.getFormValuesFromEntity(this.props.entity);

        } else {
            this.populateFormValues({
                name: '',
                settings: {
                    rootRule: {
                        type: 'all',
                        rules: []
                    }
                },
                rootRuleType: 'all',
                selectedRule: null
            });
        }
    }

    localValidateFormValues(state) {
        const t = this.props.t;

        if (!state.getIn(['name', 'value'])) {
            state.setIn(['name', 'error'], t('nameMustNotBeEmpty'));
        } else {
            state.setIn(['name', 'error'], null);
        }

        if (state.getIn(['selectedRule', 'value']) === null) {
            state.setIn(['selectedRule', 'error'], null);
        }
    }

    @withFormErrorHandlers
    async submitHandler(submitAndLeave) {
        const t = this.props.t;

        let sendMethod, url;
        if (this.props.entity) {
            sendMethod = FormSendMethod.PUT;
            url = `rest/segments/${this.props.list.id}/${this.props.entity.id}`
        } else {
            sendMethod = FormSendMethod.POST;
            url = `rest/segments/${this.props.list.id}`
        }

        try {
            this.disableForm();
            this.setFormStatusMessage('info', t('saving'));

            const submitResult = await this.validateAndSendFormValuesToURL(sendMethod, url);

            if (submitResult) {
                if (this.props.entity) {
                    if (submitAndLeave) {
                        this.navigateToWithFlashMessage(`/lists/${this.props.list.id}/segments`, 'success', t('segmentUpdated'));
                    } else {
                        await this.getFormValuesFromURL(`rest/segments/${this.props.list.id}/${this.props.entity.id}`);

                        this.enableForm();
                        this.setFormStatusMessage('success', t('segmentUpdated'));
                    }
                } else {
                    if (submitAndLeave) {
                        this.navigateToWithFlashMessage(`/lists/${this.props.list.id}/segments`, 'success', t('segmentCreated'));
                    } else {
                        this.navigateToWithFlashMessage(`/lists/${this.props.list.id}/segments/${submitResult}/edit`, 'success', t('segmentCreated'));
                    }
                }
            } else {
                this.enableForm();
                this.setFormStatusMessage('warning', t('thereAreErrorsInTheFormPleaseFixThemAnd'));
            }
        } catch (error) {
            throw error;
        }
    }

    onRulesChanged(rulesTree) {
        // This assumes that !this.state.ruleOptionsVisible
        this.getFormValue('settings').rootRule.rules = this.getRulesFromTree(rulesTree);

        this.setState({
            rulesTree
        })
    }

    showRuleOptions(rule) {
        this.updateFormValue('selectedRule', rule);

        this.setState({
            ruleOptionsVisible: true
        });
    }

    onRuleSettingsPaneClose() {
        this.updateFormValue('selectedRule', null);

        this.setState({
            ruleOptionsVisible: false,
            rulesTree: this.getTreeFromRules(this.getFormValue('settings').rootRule.rules)
        });
    }

    onRuleSettingsPaneDelete() {
        const selectedRule = this.getFormValue('selectedRule');
        this.updateFormValue('selectedRule', null);

        this.setState({
            ruleOptionsVisible: false,
        });

        this.deleteRule(selectedRule);
    }

    onRuleSettingsPaneUpdated(hasErrors) {
        this.setState(previousState => ({
            formState: previousState.formState.setIn(['data', 'selectedRule', 'error'], hasErrors)
        }));
    }

    addRule(rule) {
        if (!this.state.ruleOptionsVisible) {
            const rules = this.getFormValue('settings').rootRule.rules;
            rules.push(rule);

            this.updateFormValue('selectedRule', rule);

            this.setState({
                ruleOptionsVisible: true,
                rulesTree: this.getTreeFromRules(rules)
            });
        }
    }

    async addCompositeRule() {
        this.addRule({
            type: 'all',
            rules: []
        });
    }

    async addPrimitiveRule() {
        this.addRule({
            type: null  // Null type means a primitive rule where the type has to be chosen based on the chosen column
        });
    }

    deleteRule(ruleToDelete) {
        let finishedSearching = false;

        function childrenWithoutRule(rules) {
            const newRules = [];

            for (const rule of rules) {
                if (finishedSearching) {
                    newRules.push(rule);

                } else if (rule !== ruleToDelete) {
                    const newRule = Object.assign({}, rule);

                    if (rule.rules) {
                        newRule.rules = childrenWithoutRule(rule.rules);
                    }

                    newRules.push(newRule);

                } else {
                    finishedSearching = true;
                }
            }

            return newRules;
        }

        const rules = childrenWithoutRule(this.getFormValue('settings').rootRule.rules);

        this.getFormValue('settings').rootRule.rules = rules;

        this.setState({
            rulesTree: this.getTreeFromRules(rules)
        });
    }


    render() {
        const t = this.props.t;
        const isEdit = !!this.props.entity;
        const selectedRule = this.getFormValue('selectedRule');
        const ruleHelpers = this.ruleHelpers;

        let ruleOptionsVisibilityClass = '';
        if ('ruleOptionsVisible' in this.state) {
            if (this.state.ruleOptionsVisible) {
                ruleOptionsVisibilityClass = ' ' + styles.ruleOptionsVisible;
            } else {
                ruleOptionsVisibilityClass = ' ' + styles.ruleOptionsHidden;
            }
        }

        return (
            <DndProvider backend={isTouchDevice ? TouchBackend : HTML5Backend}>
                <div>
                    {isEdit &&
                        <DeleteModalDialog
                            stateOwner={this}
                            visible={this.props.action === 'delete'}
                            deleteUrl={`rest/segments/${this.props.list.id}/${this.props.entity.id}`}
                            backUrl={`/lists/${this.props.list.id}/segments/${this.props.entity.id}/edit`}
                            successUrl={`/lists/${this.props.list.id}/segments`}
                            deletingMsg={t('deletingSegment')}
                            deletedMsg={t('segmentDeleted')}/>
                    }

                    <Title>{isEdit ? t('editSegment') : t('createSegment')}</Title>

                    <Form stateOwner={this} onSubmitAsync={::this.submitHandler}>
                        <h3>{t('segmentOptions')}</h3>

                        <InputField id="name" label={t('name')} />
                        <Dropdown id="rootRuleType" label={t('toplevelMatchType')} options={ruleHelpers.getCompositeRuleTypeOptions()} />
                    </Form>

                    <hr />

                    <div className={styles.rulePane + ruleOptionsVisibilityClass}>
                        <div className={styles.leftPane}>
                            <div className={styles.leftPaneInner}>
                                <Toolbar>
                                    <Button className="btn-secondary" label={t('addCompositeRule')} onClickAsync={::this.addCompositeRule}/>
                                    <Button className="btn-secondary" label={t('addRule')} onClickAsync={::this.addPrimitiveRule}/>
                                </Toolbar>

                                <h3>{t('rules')}</h3>

                                <div className="clearfix"/>

                                <div className={styles.ruleTree}>
                                    <SortableTree
                                        treeData={this.state.rulesTree}
                                        onChange={rulesTree => this.onRulesChanged(rulesTree)}
                                        isVirtualized={false}
                                        canDrop={ data => !data.nextParent || (ruleHelpers.isCompositeRuleType(data.nextParent.rule.type)) }
                                        generateNodeProps={data => ({
                                            buttons: [
                                                <ActionLink onClickAsync={async () => !this.state.ruleOptionsVisible && this.showRuleOptions(data.node.rule)} className={styles.ruleActionLink}><Icon icon="edit" title={t('edit')}/></ActionLink>,
                                                <ActionLink onClickAsync={async () => !this.state.ruleOptionsVisible && this.deleteRule(data.node.rule)} className={styles.ruleActionLink}><Icon icon="trash-alt" title={t('delete')}/></ActionLink>
                                            ]
                                        })}
                                    />
                                </div>
                            </div>

                            <div className={styles.leftPaneOverlay} />

                            <div className={styles.paneDivider}>
                                <div className={styles.paneDividerSolidBackground}/>
                            </div>
                        </div>

                        <div className={styles.rightPane}>
                            <div className={styles.rightPaneInner}>
                                {selectedRule &&
                                    <RuleSettingsPane rule={selectedRule} fields={this.props.fields} onChange={this.onRuleSettingsPaneUpdatedHandler} onClose={this.onRuleSettingsPaneCloseHandler} onDelete={this.onRuleSettingsPaneDeleteHandler} forceShowValidation={this.isFormValidationShown()}/>}
                            </div>
                        </div>
                    </div>

                    <hr/>
                    <ButtonRow format="wide" className={`col-12 ${styles.toolbar}`}>
                        <Button type="submit" className="btn-primary" icon="check" label={t('save')} onClickAsync={async () => await this.submitHandler(false)}/>
                        <Button type="submit" className="btn-primary" icon="check" label={t('saveAndLeave')} onClickAsync={async () => await this.submitHandler(true)}/>

                        {isEdit && <LinkButton className="btn-danger" icon="trash-alt" label={t('delete')} to={`/lists/${this.props.list.id}/segments/${this.props.entity.id}/delete`}/> }
                    </ButtonRow>
                </div>
            </DndProvider>
        );
    }
}