import fs from 'fs'
import readline from 'readline'
import {chi2test} from '@stdlib/stats'

const line$ = (path: string) => readline.createInterface({
    input: fs.createReadStream(path),
    crlfDelay: Infinity
})

// http://geneontology.org/docs/guide-go-evidence-codes/
// http://wiki.geneontology.org/index.php/Category:Evidence_Codes
// http://current.geneontology.org/ontology/go-basic.obo
// http://current.geneontology.org/annotations/goa_human.gaf.gz

const getSymbol = async (symbol:string, goaPath:string, oboPath:string) => {
    const header = [
        'database', 'ID', 'Symbol', 'Qualifier', 
        'GO_Term', 'Evidence', 'Evidence_Code', 
        'With', 'From','Name', 'Alternative_symbols', 
        'Class', 'Taxon', 'Date', 'Origin'
    ]
    const tester = new RegExp('\t'+symbol+'\t')
    const separator = new RegExp('\\|')
    const results = [] as Array<{[key:string]:any}>
    for await (const line of line$(goaPath)) {
        if(tester.test(line)) results.push(line.split('\t').filter((e:any)=>e).reduce((p,c,i) => ({...p, [header[i]] : separator.test(c) ? c.split('|') : c}), {}))
    }

    const subTerms = results.map(e => e?.GO_Term)

    const cacheTerms = await getGOterms(subTerms, oboPath)
    for (let index = 0; index < results.length; index++) {
        const goTerm = results[index]?.GO_Term
        results[index]['GO_Term'] = cacheTerms.filter(e => e.id === goTerm)[0]
    }
    return results
}

const getGOterms = async (
    terms: string[] | string,
    oboPath: string
) => {
    terms = Array.isArray(terms) ? terms : [terms]
    const testerList = terms.map(e => new RegExp('id: ' + e))
    let delim = false
    const results = []
    let result = {} as {[key:string]: any}
    for await (const line of line$(oboPath)) {
        if (testerList.some(rx => rx.test(line))) delim = true
        if (line === '' && delim) {
            delim = false
            results.push(result)
            result = {}
        }
        if (delim) result[line.split(': ')[0]] = line.split(': ')[1]
    }
    return results
}

const getN = async (
    terms: string | string[],
    qualifiers: string | string[],
    goaPath: string,
    oboPath: string
) => {
    terms = Array.isArray(terms) ? terms : [terms]
    qualifiers = Array.isArray(qualifiers) ? qualifiers : [qualifiers]

    let qualifs = {} as {[key:string]: {[key:string]:any}}
    let termsList: any[] = []
    for (const term of terms) {
        termsList.push({
            nTotal: 0,
            genes: [],
            ...(await getGOterms(term, oboPath))[0],
            test: new RegExp('\t' + term + '\t'),
        })
    }

    qualifiers.map((e:any)=> qualifs[e] = {})
    
    for await (const line of line$(goaPath)) {
        const t = termsList.filter((rx:any) => rx.test.test(line))
        if (t.length > 0) {
            termsList = termsList.map((rx:any) => {
                if (rx.test.test(line)) {
                    const genes = [...new Set([...(rx?.genes), line.split('\t')[2]])]
                    return {...rx, nTotal:genes.length, genes}
                } else {
                    return rx
                }
            })
        }
    }
    return termsList.map((e:any)=> {
        delete e['test']
        return e
    })
}

const headerGOA = [
    'database', 'ID', 'Symbol', 'Qualifier', 
    'GO_Term', 'Evidence', 'Evidence_Code', 
    'With', 'From','Name', 'Alternative_symbols', 
    'Class', 'Taxon', 'Date', 'Origin']

const getAllSymbols = async (
    symbols: string[],
    qualifier: string,
    goaPath: string,
    oboPath: string
) => {
    symbols = Array.isArray(symbols) ? symbols : [symbols]
    const testerList = [...new Set(symbols)].map(e => new RegExp('\t' + e + '\t' + qualifier + '\t'))
    const allGoa     = [] as Array<{[key:string]:any}>
    const allGenes = {} as {[key:string]: any}
    for await (const line of line$(goaPath)) {
        if (testerList.some(rx => rx.test(line))) {
            allGoa.push(
                line.split('\t').
                reduce((p,c,i) => ({...p, [headerGOA[i]] : c}), {})
            )
        }
        allGenes[line.split('\t')[2]] = {}
    }
    const nAllGenes = Object.keys(allGenes).length
    console.log(nAllGenes);
    
    const allIDs = await getN([...new Set(allGoa.map((e:any)=> e.GO_Term))], qualifier, goaPath, oboPath)
    
    return allIDs.map((e:any) => {
        const observedGenes = symbols.filter((ee:string)=> e.genes.includes(ee))
        // const observedGenesNotIn = symbols.filter((ee:string)=> !e.genes.includes(ee))
        // const allIn = Object.keys(allGenes).filter((ee:any)=>)
        const diff = e.genes.length - observedGenes.length
        return {
            n: observedGenes.length,
            prop: observedGenes.length/e.genes.length,
            chi2test: chi2test(
                [[observedGenes.length,
                diff < 0 ? 0 : diff],
                [symbols.length,
                nAllGenes]]
            ).pValue,
            observedGenes,
            ...e
        }
    }).sort((a,b) => b.chi2test - a.chi2test)
}

export { getSymbol, getGOterms, getN, getAllSymbols }