import { IViewPoint, ITopic, VisualizationInfo, IHeader, IMarkup } from "./schema"
import { IHelpers } from "./IHelpers"
import { Reader, TypedArray, unzip, ZipEntry, ZipInfo } from 'unzipit'
import { IExtensionsSchema, IProject } from "./schema/project"
import { XMLParser } from "fast-xml-parser"

export default class BcfReader {

    version: string
    bcf_archive: ZipInfo | undefined
    project: IProject | undefined
    markups: Markup[] = []
    helpers: IHelpers

    constructor(version: string, helpers: IHelpers) {
        this.version = version
        this.helpers = helpers
    }

    read = async (src: string | ArrayBuffer | TypedArray | Blob | Reader) => {
        try {
            const markups: ZipEntry[] = []

            this.bcf_archive = await unzip(src)

            const { entries } = this.bcf_archive
            let projectId: string = ''
            let projectName: string = ''
            let projectVersion: string = ''
            let extension_schema: IExtensionsSchema | undefined = undefined

            for (const [name, entry] of Object.entries(entries)) {

                if (name.endsWith('.bcf')) {
                    markups.push(entry)
                }

                else if (name.endsWith('.version')) {
                    const parsedEntry = new XMLParser(this.helpers.XmlParserOptions).parse(await entry.text())
                    projectVersion = parsedEntry.Version.DetailedVersion
                }

                else if (name.endsWith('.bcfp')) {
                    const parsedEntry = new XMLParser(this.helpers.XmlParserOptions).parse(await entry.text())

                    if (!parsedEntry.ProjectExtension || !parsedEntry.ProjectExtension.Project)
                        continue //NOTE: Throw an error here?

                    projectId = parsedEntry.ProjectExtension.Project["@_ProjectId"] || '' //NOTE: Throw an error here?
                    projectName = parsedEntry.ProjectExtension.Project.Name || ''
                }

                else if (name.endsWith('extensions.xsd')) {
                    const parsedEntry = new XMLParser(this.helpers.XmlParserOptions).parse(await entry.text())
                    extension_schema = this.helpers.XmlToJsonNotation(parsedEntry)
                }
            }

            const purged_markups: IMarkup[] = []

            for (let i = 0; i < markups.length; i++) {
                const t = markups[i]
                const markup = new Markup(this, t)
                await markup.read()
                this.markups.push(markup)

                const purged_markup = { header: markup.header, topic: markup.topic, project: this.project, viewpoints: markup.viewpoints } as IMarkup
                purged_markups.push(purged_markup)
            }

            this.project = {
                project_id: projectId,
                name: projectName,
                version: projectVersion,
                markups: undefined,
                reader: this,
                extension_schema: extension_schema
            }

            this.project.markups = purged_markups.map(mkp => { return { ...mkp, project: this.project } as IMarkup })

        } catch (e) {
            console.log("Error in loading BCF archive. The error below was thrown.")
            console.error(e)
        }
    }

    getEntry = (name: string) => {
        return this.bcf_archive?.entries[name]
    }

}

export class Markup {

    readonly reader: BcfReader
    readonly markup_file: ZipEntry

    header: IHeader | undefined
    topic: ITopic | undefined
    viewpoints: VisualizationInfo[] = []

    constructor(reader: BcfReader, markup: ZipEntry) {
        this.reader = reader
        this.markup_file = markup
    }

    read = async () => {
        await this.parseMarkup()
        await this.parseViewpoints()
    }

    private parseMarkup = async () => {
        const markup = this.reader.helpers.GetMarkup(await this.markup_file.text())
        this.topic = markup.topic
        this.header = markup.header
    }

    private parseViewpoints = async () => {
        if (!this.topic) return

        if (this.topic.viewpoints) {

            const topic_viewpoints = this.topic.viewpoints

            for (let i = 0; i < topic_viewpoints.length; i++) {
                const entry = topic_viewpoints[i]
                const key = this.topic.guid + "/" + entry.viewpoint
                const file = this.reader.getEntry(key)

                if (!file) throw new Error("Missing Visualization Info")
                const viewpoint = this.reader.helpers.GetViewpoint(await file.text())
                if(viewpoint)
                {
                    viewpoint.snapshot = entry.snapshot
                    viewpoint.getSnapshot = async () => { if (entry.snapshot) return await this.getSnapshot(entry.snapshot) }
                    this.viewpoints.push(viewpoint)
                }    
            }
        }
    }

    /**
     * Parses the png snapshot.
     * 
     * @returns {string} The image in base64String format.
     * 
     * @deprecated This function is deprecated and will be removed in the next version.<br>
     * Please use viewpoint.getSnapshot() instead.<br>
     *
    */
    getViewpointSnapshot = async (viewpoint: VisualizationInfo | IViewPoint): Promise<string | undefined> => {
        if (!viewpoint || !this.topic) return
        const entry = this.reader.getEntry(`${this.topic.guid}/${viewpoint.snapshot}`)
        if (entry) {
            const arrayBuffer = await entry.arrayBuffer()
            return btoa(String.fromCharCode.apply(null, new Uint8Array(arrayBuffer) as any))
        }
    }

    /**
     * Parses the png snapshot.
     *
     * @returns {string} The image in base64String format.
    */
    getSnapshot = async (guid: string): Promise<string | undefined> => {
        if (!guid || !this.topic) return
        const entry = this.reader.getEntry(`${this.topic.guid}/${guid}`)
        if (entry) {
            const arrayBuffer = await entry.arrayBuffer()
            return btoa(String.fromCharCode.apply(null, new Uint8Array(arrayBuffer) as any))
        }
    }
}