import cmp from 'semver-compare'
import * as semver from 'semver'
import { injectable, inject } from 'inversify'

import { IBuildAgent, TYPES } from './models'

export interface IVersionManager {
    isExplicitVersion(versionSpec: string): boolean
    evaluateVersions(versions: string[], versionSpec: string): string
    cleanVersion(version: string): string
}

@injectable()
export class VersionManager implements IVersionManager {
    private buildAgent: IBuildAgent
    constructor(@inject(TYPES.IBuildAgent) buildAgent: IBuildAgent) {
        this.buildAgent = buildAgent
    }

    public isExplicitVersion(versionSpec: string): boolean {
        const c = semver.clean(versionSpec)
        this.buildAgent.debug('isExplicit: ' + c)

        const valid = semver.valid(c) != null
        this.buildAgent.debug('explicit? ' + valid)

        return valid
    }

    public evaluateVersions(versions: string[], versionSpec: string): string {
        let version: string
        this.buildAgent.debug('evaluating ' + versions.length + ' versions')
        versions = versions.sort(cmp)
        for (let i = versions.length - 1; i >= 0; i--) {
            const potential: string = versions[i]
            const satisfied: boolean = semver.satisfies(potential, versionSpec)
            if (satisfied) {
                version = potential
                break
            }
        }

        if (version) {
            this.buildAgent.debug('matched: ' + version)
        } else {
            this.buildAgent.debug('match not found')
        }

        return version
    }

    public cleanVersion(version: string): string {
        this.buildAgent.debug('cleaning: ' + version)
        return semver.clean(version)
    }
}