import pathUtil from 'path'
import { diskUtil } from '@sprucelabs/spruce-skill-utils'
import chokidar from 'chokidar'
import { GeneratedFile, GeneratedFileOrDir } from '../../types/cli.types'
import AbstractFeature from '../AbstractFeature'
import { FeatureCode } from '../features.types'

export default class WatchFeature extends AbstractFeature {
    public description =
        'Watches for changes on the file system and emits app level events for other features to respond to.'
    public code: FeatureCode = 'watch'
    public nameReadable = 'Watch'

    private _isWatching = false
    private watcher?: any

    private timeoutId?: NodeJS.Timeout
    private changesSinceLastChange: GeneratedFileOrDir[] = []

    public async isWatching() {
        return this._isWatching
    }

    public async startWatching(options?: {
        delay?: number
        sourceDir?: string
    }) {
        this._isWatching = true

        const watchDir = diskUtil.resolvePath(
            this.cwd,
            options?.sourceDir ?? ''
        )

        this.watcher = chokidar.watch(
            [
                diskUtil.resolvePath(watchDir, 'build'),
                diskUtil.resolvePath(watchDir, 'dist'),
            ],
            {
                ignoreInitial: true,
            }
        )

        this.watcher.on('all', async (action: ChokidarAction, path: string) => {
            this.changesSinceLastChange.push({
                id: this.mapChokidarActionToSchemaId(action),
                values: {
                    action: this.mapChokidarActionToGeneratedAction(action),
                    path,
                    name: pathUtil.basename(path),
                },
            })

            if (this.timeoutId) {
                clearTimeout(this.timeoutId)
            }

            this.timeoutId = setTimeout(async () => {
                await this.fireChange()
            }, options?.delay ?? 500)
        })
    }

    private mapChokidarActionToSchemaId(
        action: ChokidarAction
    ): GeneratedFileOrDir['id'] {
        return action.search(/dir/gi) > -1 ? 'generatedDir' : 'generatedFile'
    }

    private mapChokidarActionToGeneratedAction(chokidar: ChokidarAction) {
        const map = {
            add: 'generated',
            addDir: 'generated',
            change: 'updated',
            unlink: 'deleted',
            unlinkDir: 'deleted',
        }

        return map[chokidar] as GeneratedFile['action']
    }

    private async fireChange() {
        const changes = this.changesSinceLastChange
        this.changesSinceLastChange = []

        await this.emitter.emitAndFlattenResponses(
            'watcher.did-detect-change',
            {
                changes,
            }
        )
    }

    public async stopWatching() {
        this._isWatching = false
        await this.watcher?.close()
    }
}

type ChokidarAction = 'add' | 'addDir' | 'change' | 'unlink' | 'unlinkDir'

declare module '../../features/features.types' {
    interface FeatureMap {
        watch: WatchFeature
    }

    interface FeatureOptionsMap {
        watch: undefined
    }
}