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

function parseTemplate(description: string): { warnings: string[] } & { [k: string]: string } {

    const u = new (new Mwn().Wikitext)(description)
    const r = u.parseTemplates({
        namePredicate: (name) => name === "DanceWorkshopDescription",
    })
    const warnings = []
    if (r.length < 1) {
        throw new Error("Could not find DanceWorkshopDescription")
    }
    if (r.length > 1) {
        warnings.push("More than one DanceWorkshopDescription template found")
    }
    const p = r[0]
    const properties = p.parameters.map(v => ({ [v.name]: v.value }))
    return Object.assign({}, { warnings }, ...properties)
}

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'].trim()
}

export function parseSummary(description: string, name: string): VideoDescription {

    const properties = parseTemplate(description)

    const b: Partial<VideoDescription> = {};
    b.nags = properties.warnings

    if (Object.hasOwn(properties, 'teachers')) {
        b.nags.push(`Contains 'teachers' key instead of 'leader'/'follower'`)
        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


    if (!Object.hasOwn(properties, 'patterns')) {
        b.nags.push(`No 'patterns' key`)
        try {
            b.patterns = parseBlock("Shown Patterns", description)
        } catch (e) {
            b.nags.push("Shown Patterns: " + e)
            b.patterns = ""
        }
    } else {
        b.patterns = properties['patterns']
    }

    if (!Object.hasOwn(properties, 'notes')) {
        b.nags.push(`No 'notes' key`)
        try {
            b.notes = parseBlock("Notes", description)
        } catch (e) {
            b.nags.push("Notes: " + e)
            b.notes = ""
        }
    } else {
        b.notes = properties['notes']
    }
    b.path = name
    const titleMatch = name.match(/File:WCS \w+ (?<title>.+)\.[^.]+/)
    b.title = titleMatch?.groups ? titleMatch.groups['title'] : name
    return (b as VideoDescription)
}