import { VideoDescription } from "./main.ts";

export function parseTemplate(description: string): Record<string, string> {

    const templateRegex = /{{(.*DanceWorkshopDescription.*)}}/s;

    const match = description.match(templateRegex);

    if (!match) {
        throw new Error("Could not find template")
    }

    const propertyRegex = /\|\s*(?<key>[^|]*?)\s*=(?<value>[^|}]*)\s*$/gm

    const properties = match[1].matchAll(propertyRegex).map(v => {
        if (!v.groups) { throw new Error("Faulty regex") };
        return ({ [v.groups['key'].trim()]: v.groups['value'].trim() })
    })
    return Object.assign({}, ...Array.from(properties))
}

export function parseSummary(description: string, name: string): VideoDescription {
    const properties = parseTemplate(description)

    const b: Partial<VideoDescription> = {};

    if (Object.hasOwn(properties, 'teachers')) {
        console.warn(`Page ${name} has old template usage [contains 'teachers' key]`)
        const t = properties['teachers'].split('&').map(item => item.trim());
        b.teachers = t
    } else {
        b.teachers = [properties['leader'], properties['follower']].filter(v => v !== undefined)
    }

    b.location = properties['location']
    b.date = properties['date']
    b.level = properties['level']

    b.event = properties['event'] || b.location

    function parseBlock(header: string, text: string): string {
        const regex = new RegExp(`===\\s*${header}\\s*===\\s*(?<content>(^\\s*[:*]+.*$\\s+)+)`, "m")
        const match = text.match(regex)
        if (!match) {
            throw new Error(`Could not find block ${header}`)
        }
        if (!match.groups) {
            throw new Error("Faulty regex")
        }
        return match.groups['content']
    }
    if (!Object.hasOwn(properties, 'patterns')) {
        console.warn(`Page ${name} has old template usage [no 'patterns' key]`)
        b.patterns = parseBlock("Shown Patterns", description)
    } else {
        b.patterns = properties['patterns']
    }

    if (!Object.hasOwn(properties, 'notes')) {
        console.warn(`Page ${name} has old template usage [no 'notes' key]`)
        b.notes = parseBlock("Notes", description)
    } else {
        b.notes = properties['notes']
    }

    return (b as VideoDescription)
}