import { buildSync, BuildFailure, BuildOptions } from 'esbuild'
import { existsSync, writeFileSync, unlinkSync } from 'fs'
import { DistPath, ScriptBase, ScriptPath } from './paths'
import { UserScriptMetaFull } from './types'
import readMeta from './readmeta'
import { format, Options } from 'prettier'
import { CLIArgs } from './main'

export default function (
    name: string,
    watchCallback: (meta: UserScriptMetaFull, error: string | null) => void,
    PrettierConfig: Options,
    CLIArgs: CLIArgs
): [UserScriptMetaFull, string | null] {
    //read meta file
    let [metaJson, metaString] = readMeta(name)
    let pathDist = DistPath(name)

    let result = runEsbuild(
        {
            entryPoints: [ScriptPath(name).main],
            outfile: pathDist,

            target: 'esnext',
            platform: 'node',
            format: 'esm',

            bundle: true,
            minify: CLIArgs.minify,

            define: {
                UserScriptName: `'${metaJson.name}'`,
                UserScriptNamespace: `'${metaJson.namespace}'`,
                UserScriptVersion: `'${metaJson.version}'`,

                UserScriptDownloadURL: `'${metaJson.downloadURL}'`,
                UserScriptSupportURL: `'${metaJson.supportURL}'`,
                UserScriptHomepageURL: `'${metaJson.homepageURL}'`,
            },
        },
        result => {
            let error = runPostEsbuild(
                name,
                result,
                metaString,
                CLIArgs,
                PrettierConfig
            )
            watchCallback(metaJson, error)
        },
        CLIArgs
    )

    let error = runPostEsbuild(
        name,
        result,
        metaString,
        CLIArgs,
        PrettierConfig
    )

    return [metaJson, error]
}

function doErrorFile(
    pathError: string,
    pathOutFile: string,
    error: string | null
) {
    if (error !== null) {
        writeFileSync(pathError, `${new Date().toISOString()}\n\n${error}`)

        if (existsSync(pathOutFile)) {
            unlinkSync(pathOutFile)
        }
    } else if (existsSync(pathError)) {
        unlinkSync(pathError)
    }
}

interface RunEsbuildResult {
    content: string | null
    error: string | null
    errorRaw?: BuildFailure
}

function runEsbuild(
    opts: BuildOptions,
    watchCallback: (result: RunEsbuildResult) => void,
    CLIArgs: CLIArgs
): RunEsbuildResult {
    opts.write = false
    if (CLIArgs.watch) {
        opts.watch = {
            onRebuild(err, res) {
                if (err) {
                    watchCallback({
                        content: null,
                        error: (err as BuildFailure).message,
                        errorRaw: err,
                    })
                } else if (res) {
                    let content = ''
                    if (res.outputFiles && res.outputFiles.length > 0) {
                        content = res.outputFiles[0].text
                    }
                    if (content === '') {
                        watchCallback({
                            content: null,
                            error: 'No output',
                        })
                    }
                    watchCallback({
                        content,
                        error: null,
                    })
                } else {
                    watchCallback({
                        content: null,
                        error: 'No result',
                    })
                }
            },
        }
    }

    try {
        let res = buildSync(opts)
        let content = ''
        if (res.outputFiles && res.outputFiles.length > 0) {
            content = clearFilenameComments(res.outputFiles[0].text)
        }
        if (content === '') {
            return {
                content: null,
                error: 'No output',
            }
        }
        return {
            content,
            error: null,
        }
    } catch (err) {
        return {
            content: null,
            error: (err as BuildFailure).message,
        }
    }
}

function runPostEsbuild(
    name: string,
    result: RunEsbuildResult,
    metaString: string,
    CLIArgs: CLIArgs,
    PrettierConfig: Options
) {
    let error: string | null = null
    let path = ScriptPath(name)
    let pathDist = DistPath(name)

    if (result.error) {
        console.error(name, result.errorRaw || result.error)
        error = result.error
    } else if (result.content) {
        let content = metaString + result.content
        if (CLIArgs.prettier) {
            content = format(content, PrettierConfig)
        }
        writeFileSync(pathDist, content)
    } else {
        console.error(name, 'No output')
    }

    doErrorFile(path.error, pathDist, error)

    return error
}

//remove all filename comments
function clearFilenameComments(content: string): string {
    let regexp = new RegExp(`//\\s*${ScriptBase}/.*(?:\\n|$)`, 'g')
    return content.replace(regexp, '')
}