package com.geekorum.build

import org.gradle.api.Project

import java.io.File

import java.io.IOException

import java.util.concurrent.TimeUnit

internal fun Project.getGitSha1(): String? = runCommand("git rev-parse HEAD", workingDir = projectDir)?.trim()

internal fun Project.getHgSha1(): String? = runCommand("hg id --debug -i -r .", workingDir = projectDir)?.trim()

internal fun Project.getHgLocalRevisionNumber(): String? = runCommand("hg id -n -r .", workingDir = projectDir)?.trim()

fun Project.getChangeSet(): String {

    val git = rootProject.file(".git")

    val hg = rootProject.file(".hg")

    return when {

        git.exists() -> "git:${getGitSha1()}"

        hg.exists() -> "hg:${getHgSha1()}"

        else -> "unknown"

    }

}

/**

 * Compute a version code following this format : MmmPBBB

 * M is major, mm is minor, P is patch

 * BBB is build version number from hg

 */

fun Project.computeChangesetVersionCode(major: Int = 0, minor: Int = 0, patch: Int = 0): Int {

    val base = (major * 1000000) + (minor * 10000) + (patch * 1000)

    return base + (getHgLocalRevisionNumber()?.trim()?.toIntOrNull() ?: 0)

}

private fun Project.runCommand(

    command: String,

    workingDir: File = File("."),

    timeoutAmount: Long = 60,

    timeoutUnit: TimeUnit = TimeUnit.MINUTES

): String? {

    return try {

        ProcessBuilder(*command.split("\\s".toRegex()).toTypedArray())

            .directory(workingDir)

            .redirectOutput(ProcessBuilder.Redirect.PIPE)

            .redirectError(ProcessBuilder.Redirect.PIPE)

            .start().apply {

                waitFor(timeoutAmount, timeoutUnit)

            }.inputStream.bufferedReader().readText()

    } catch (e: IOException) {

        logger.info("Unable to run command", e)

        null

    }

}