/**
 * IOManager.js
 *
 * @author realor
 */

import { ObjectUtils } from '../utils/ObjectUtils.js'
import { WebUtils } from '../utils/WebUtils.js'
import * as THREE from '../lib/three.module.js'

class IOManager {
    static formats = {}

    static getFormat(fileName) {
        let extension = null
        if (typeof fileName === 'string') {
            let index = fileName.lastIndexOf('.')
            if (index !== -1) {
                extension = fileName.substring(index + 1).toLowerCase()
            }
        }
        if (extension === null) return null
        for (let formatName in this.formats) {
            let formatInfo = this.formats[formatName]
            if (formatInfo.extensions.indexOf(extension) !== -1) return formatName
        }
        return null
    }

    static getFormatInfo(fileName) {
        let formatName = this.getFormat(fileName)
        let formatInfo = formatName ? IOManager.formats[formatName] : IOManager.formats[fileName]
        return formatInfo || null
    }

    static load(intent) {
        let formatName = intent.format
        let url = intent.url
        let data = intent.data
        let onCompleted = intent.onCompleted // onCompleted(object3D)
        let onProgress = intent.onProgress // onProgress({progress: 0..100, message: text})
        let onError = intent.onError // onError(error)
        let manager = intent.manager // LoadingManager
        let units = intent.units || 'm' // application units
        let basicAuthCredentials = intent.basicAuthCredentials

        try {
            if (!formatName && url) {
                formatName = this.getFormat(url)
            }
            if (!formatName) throw "Can't determinate format"

            let formatInfo = IOManager.formats[formatName]

            let loader
            if (formatInfo && formatInfo.loader) {
                loader = new formatInfo.loader.class(manager)
                loader.loadMethod = formatInfo.loader.loadMethod || 0
            } else throw 'Unsupported format: ' + formatName

            const options = Object.assign({}, formatInfo.loader.options, intent.options)

            if (data) {
                this.parseData(loader, url, data, units, onCompleted, onProgress, onError, options)
            } else {
                let request = new XMLHttpRequest()
                let length = -1
                request.onreadystatechange = () => {
                    if (request.readyState === 4) {
                        if (onProgress) onProgress({ progress: 100, message: '' })

                        if (request.status === 0 || request.status === 200 || request.status === 207) {
                            if (formatInfo.loader.dataType === 'arraybuffer') {
                                data = request.response.arrayBuffer()
                            } else {
                                data = request.responseText
                            }
                            this.parseData(loader, url, data, units, onCompleted, onProgress, onError, options)
                        } else {
                            if (onError) {
                                let message = WebUtils.getHttpStatusMessage(request.status)
                                onError(message + ' (HTTP ' + request.status + ')')
                            }
                        }
                    } else if (request.readyState === 3) {
                        if (onProgress) {
                            if (length === -1) {
                                length = request.getResponseHeader('Content-Length')
                            } else {
                                let progress
                                if (length > 0) {
                                    progress = Math.round((100 * request.responseText.length) / length)
                                } else {
                                    progress = undefined
                                }
                                let message = 'Downloading file...'
                                onProgress({ progress: progress, message: message })
                            }
                        }
                    }
                }
                request.open('GET', url, true)
                if (basicAuthCredentials) {
                    WebUtils.setBasicAuthorization(request, basicAuthCredentials.username, basicAuthCredentials.password)
                }
                request.send()
            }
        } catch (ex) {
            if (onError) onError(ex)
        }
    }

    static export(intent) {
        let formatName = intent.format
        let fileName = intent.name
        let onCompleted = intent.onCompleted
        let onProgress = intent.onProgress
        let onError = intent.onError
        let object = intent.object

        try {
            if (!formatName && fileName) {
                formatName = this.getFormat(fileName)
            }

            if (!formatName) throw "Can't determinate format"

            let formatInfo = IOManager.formats[formatName]

            let exporter
            if (formatInfo && formatInfo.exporter) {
                exporter = new formatInfo.exporter.class()
                exporter.exportMethod = formatInfo.exporter.exportMethod || 0
                exporter.mimeType = formatInfo.mimeType || 'application/octet-stream'
            } else throw 'Unsupported format: ' + formatName

            const options = Object.assign({}, formatInfo.exporter.options, intent.options)

            this.parseObject(exporter, object, onCompleted, onProgress, onError, options)
        } catch (ex) {
            if (onError) onError(ex)
        }
    }

    static parseData(loader, url, data, units, onCompleted, onProgress, onError, options) {
        const loadCompleted = model => {
            ObjectUtils.scaleModel(model, units)
            model.traverse(object => object.updateMatrix())
            if (onCompleted) onCompleted(model)
        }

        try {
            if (loader.loadMethod === 1) {
                // ColladaLoader
                let path = THREE.LoaderUtils.extractUrlBase(url)
                let result = loader.parse(data, path)
                loadCompleted(result.scene)
            } else if (loader.loadMethod === 2) {
                // IFCLoader
                loader.parse(data, loadCompleted, onProgress, onError, options)
            } else if (loader.loadMethod === 3) {
                // GLTFLoader
                let path = THREE.LoaderUtils.extractUrlBase(url)
                loader.parse(data, path, result => loadCompleted(result.scene), onError)
            } // general case: BRFLoader, STLLoader, OBJLoader...
            else {
                let result = loader.parse(data)
                let object = this.createObject(result)
                loadCompleted(object)
            }
        } catch (ex) {
            if (onError) onError(ex)
        }
    }

    static parseObject(exporter, object, onCompleted, onProgress, onError, options) {
        const exportCompleted = result => {
            let data = ''
            if (result) {
                let mimeType = exporter.mimeType
                if (typeof result === 'string') {
                    data = new Blob([result], { type: mimeType })
                } else if (result instanceof ArrayBuffer) {
                    data = new Blob([result], { type: mimeType })
                } else if (typeof result.data === 'string') {
                    data = new Blob([result.data], { type: mimeType })
                } else if (typeof result === 'object') {
                    data = new Blob([JSON.stringify(result)], { type: mimeType })
                } else {
                    console.warn('Unsupported export result', result)
                }
            }
            if (onCompleted) onCompleted(data)
        }

        try {
            if (exporter.exportMethod === 1) {
                exporter.parse(object, exportCompleted, onError, options)
            } // general export method
            else {
                exportCompleted(exporter.parse(object, options))
            }
        } catch (ex) {
            if (onError) onError(ex)
        }
    }

    static createObject(result) {
        if (result instanceof THREE.BufferGeometry) {
            let geometry = result
            let material = new THREE.MeshPhongMaterial({ color: 0x008000, side: THREE.DoubleSide })
            return new THREE.Mesh(geometry, material)
        } else if (result instanceof THREE.Object3D) {
            return result
        }
    }

    static getSupportedLoaderExtensions() {
        const extensions = []
        const formats = IOManager.formats
        for (let formatName in formats) {
            let formatInfo = formats[formatName]
            extensions.push(...formatInfo.extensions)
        }
        return extensions
    }
}

export { IOManager }