/**
 * Copyright (c) 2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author David Sehnal <david.sehnal@gmail.com>
 */

import { BehaviorSubject } from 'rxjs';
import { debounceTime, skip } from 'rxjs/operators';
import { AlphaOrbital, Basis } from '../../extensions/alpha-orbitals/data-model';
import { SphericalBasisOrder } from '../../extensions/alpha-orbitals/spherical-functions';
import { BasisAndOrbitals, CreateOrbitalDensityVolume, CreateOrbitalRepresentation3D, CreateOrbitalVolume, StaticBasisAndOrbitals } from '../../extensions/alpha-orbitals/transforms';
import { canComputeGrid3dOnGPU } from '../../mol-gl/compute/grid3d';
import { PluginStateObject } from '../../mol-plugin-state/objects';
import { createPluginUI } from '../../mol-plugin-ui';
import { PluginUIContext } from '../../mol-plugin-ui/context';
import { DefaultPluginUISpec } from '../../mol-plugin-ui/spec';
import { PluginCommands } from '../../mol-plugin/commands';
import { PluginConfig } from '../../mol-plugin/config';
import { StateObjectSelector, StateTransformer } from '../../mol-state';
import { Color } from '../../mol-util/color';
import { ColorNames } from '../../mol-util/color/names';
import { ParamDefinition } from '../../mol-util/param-definition';
import { mountControls } from './controls';
import { DemoMoleculeSDF, DemoOrbitals } from './example-data';
import './index.html';
require('mol-plugin-ui/skin/light.scss');

interface DemoInput {
    moleculeSdf: string,
    basis: Basis,
    order: SphericalBasisOrder,
    orbitals: AlphaOrbital[]
}

interface Params {
    show: { name: 'orbital', params: { index: number } } | { name: 'density', params: {} },
    isoValue: number,
    gpuSurface: boolean
}

type Selectors = {
    type: 'orbital',
    volume: StateObjectSelector<PluginStateObject.Volume.Data, typeof CreateOrbitalVolume>,
    positive: StateObjectSelector<PluginStateObject.Volume.Representation3D, typeof CreateOrbitalRepresentation3D>
    negative: StateObjectSelector<PluginStateObject.Volume.Representation3D, typeof CreateOrbitalRepresentation3D>
} | {
    type: 'density',
    volume: StateObjectSelector<PluginStateObject.Volume.Data, typeof CreateOrbitalDensityVolume>,
    positive: StateObjectSelector<PluginStateObject.Volume.Representation3D, typeof CreateOrbitalRepresentation3D>
}

export class AlphaOrbitalsExample {
    plugin: PluginUIContext;

    async init(target: string | HTMLElement) {
        const defaultSpec = DefaultPluginUISpec();
        this.plugin = await createPluginUI(typeof target === 'string' ? document.getElementById(target)! : target, {
            ...defaultSpec,
            layout: {
                initial: {
                    isExpanded: false,
                    showControls: false
                },
            },
            components: {
                controls: { left: 'none', right: 'none', top: 'none', bottom: 'none' },
            },
            canvas3d: {
                camera: {
                    helper: { axes: { name: 'off', params: {} } }
                }
            },
            config: [
                [PluginConfig.Viewport.ShowExpand, false],
                [PluginConfig.Viewport.ShowControls, false],
                [PluginConfig.Viewport.ShowSelectionMode, false],
                [PluginConfig.Viewport.ShowAnimation, false],
            ]
        });

        this.plugin.managers.interactivity.setProps({ granularity: 'element' });

        if (!canComputeGrid3dOnGPU(this.plugin.canvas3d?.webgl)) {
            PluginCommands.Toast.Show(this.plugin, {
                title: 'Error',
                message: `Browser/device does not support required WebGL extension (OES_texture_float).`
            });
            return;
        }

        this.load({
            moleculeSdf: DemoMoleculeSDF,
            ...DemoOrbitals
        });

        mountControls(this, document.getElementById('controls')!);
    }

    readonly params = new BehaviorSubject<ParamDefinition.For<Params>>({} as any);
    readonly state = new BehaviorSubject<Params>({ show: { name: 'orbital', params: { index: 32 } }, isoValue: 1, gpuSurface: false });

    private selectors?: Selectors = void 0;
    private basis?: StateObjectSelector<BasisAndOrbitals> = void 0;

    private currentParams: Params = { ...this.state.value };

    private clearVolume() {
        if (!this.selectors) return;
        const v = this.selectors.volume;
        this.selectors = void 0;
        return this.plugin.build().delete(v).commit();
    }

    private async syncVolume() {
        if (!this.basis?.isOk) return;

        const state = this.state.value;

        if (state.show.name !== this.selectors?.type) {
            await this.clearVolume();
        }

        const update = this.plugin.build();
        if (state.show.name === 'orbital') {
            if (!this.selectors) {
                const volume = update
                    .to(this.basis)
                    .apply(CreateOrbitalVolume, { index: state.show.params.index });

                const positive = volume.apply(CreateOrbitalRepresentation3D, this.volumeParams('positive', ColorNames.blue)).selector;
                const negative = volume.apply(CreateOrbitalRepresentation3D, this.volumeParams('negative', ColorNames.red)).selector;

                this.selectors = { type: 'orbital', volume: volume.selector, positive, negative };
            } else {
                const index = state.show.params.index;
                update.to(this.selectors.volume).update(CreateOrbitalVolume, () => ({ index }));
            }
        } else {
            if (!this.selectors) {
                const volume = update
                    .to(this.basis)
                    .apply(CreateOrbitalDensityVolume);
                const positive = volume.apply(CreateOrbitalRepresentation3D, this.volumeParams('positive', ColorNames.blue)).selector;
                this.selectors = { type: 'density', volume: volume.selector, positive };
            }
        }

        await update.commit();

        if (this.currentParams.gpuSurface !== this.state.value.gpuSurface) {
            await this.setIsovalue();
        }

        this.currentParams = this.state.value;
    }

    private setIsovalue() {
        if (!this.selectors) return;

        this.currentParams = this.state.value;
        const update = this.plugin.build();
        update.to(this.selectors.positive).update(this.volumeParams('positive', ColorNames.blue));
        if (this.selectors?.type === 'orbital') {
            update.to(this.selectors.negative).update(this.volumeParams('negative', ColorNames.red));
        }
        return update.commit();
    }

    private volumeParams(kind: 'positive' | 'negative', color: Color): StateTransformer.Params<typeof CreateOrbitalRepresentation3D> {
        return {
            alpha: 0.85,
            color,
            directVolume: this.state.value.gpuSurface,
            kind,
            relativeIsovalue: this.state.value.isoValue,
            pickable: false,
            xrayShaded: true,
            tryUseGpu: false
        };
    }

    async load(input: DemoInput) {
        await this.plugin.clear();

        const data = await this.plugin.builders.data.rawData({ data: input.moleculeSdf }, { state: { isGhost: true } });
        const trajectory = await this.plugin.builders.structure.parseTrajectory(data, 'mol');
        const model = await this.plugin.builders.structure.createModel(trajectory);
        const structure = await this.plugin.builders.structure.createStructure(model);

        const all = await this.plugin.builders.structure.tryCreateComponentStatic(structure, 'all');
        if (all) await this.plugin.builders.structure.representation.addRepresentation(all, { type: 'ball-and-stick', color: 'element-symbol', colorParams: { carbonColor: { name: 'element-symbol', params: {} } } });


        this.basis = await this.plugin.build().toRoot()
            .apply(StaticBasisAndOrbitals, { basis: input.basis, order: input.order, orbitals: input.orbitals })
            .commit();

        await this.syncVolume();

        this.params.next({
            show: ParamDefinition.MappedStatic('orbital', {
                'orbital': ParamDefinition.Group({
                    index: ParamDefinition.Numeric(32, { min: 0, max: input.orbitals.length - 1 }, { immediateUpdate: true, isEssential: true }),
                }),
                'density': ParamDefinition.EmptyGroup()
            }, { cycle: true }),
            isoValue: ParamDefinition.Numeric(this.currentParams.isoValue, { min: 0.5, max: 3, step: 0.1 }, { immediateUpdate: true, isEssential: false }),
            gpuSurface: ParamDefinition.Boolean(this.currentParams.gpuSurface, { isHidden: true })
        });

        this.state.pipe(skip(1), debounceTime(1000 / 24)).subscribe(async params => {
            if (params.show.name !== this.currentParams.show.name
                || (params.show.name === 'orbital' && this.currentParams.show.name === 'orbital' && params.show.params.index !== this.currentParams.show.params.index)) {
                this.syncVolume();
            } else if (params.isoValue !== this.currentParams.isoValue || params.gpuSurface !== this.currentParams.gpuSurface) {
                this.setIsovalue();
            }
        });
    }
}

(window as any).AlphaOrbitalsExample = new AlphaOrbitalsExample();