/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import groovy.json.JsonSlurper
import java.nio.charset.StandardCharsets
import java.security.MessageDigest
import javax.inject.Inject
import org.gradle.api.provider.ValueSource
import org.gradle.api.provider.ValueSourceParameters
import org.gradle.process.ExecOperations

// Loads the mach environment configurations into a gradle extension property.
//
// This script runs during Gradle configuration. Originally it called `./mach
// environment` to get the full build configuration, but that's expensive (often 2-3
// seconds). Now, `./mach configure` dumps the configuration to
// `config.status.json`, so we just need to know the topobjdir to read it.
// Determining the topobjdir without mach would require duplicating topobjdir
// resolution logic, so we run `./mach environment` to get just the topobjdir.
//
// We use two layers of caching to avoid running `./mach environment` unnecessarily:
//
// 1. Gradle's configuration cache (via ValueSource API): We declare all inputs that
//    affect topobjdir resolution as ValueSource parameters. When these inputs are
//    unchanged, Gradle reuses the entire cached configuration without calling obtain().
//
// 2. Local file cache (inside obtain()): When Gradle's config cache is invalidated
//    for other reasons (e.g., build script changes), we still check our local cache
//    before running `./mach environment`. This cache is stored in
//    .gradle/mach-environment-cache/ and keyed by a hash of the same inputs.
//
// This means `./mach environment` only runs when inputs actually change.

def startTime = System.currentTimeMillis()
logger.debug("mozconfig.gradle> Loading mach environment")

if (!ext.hasProperty("topsrcdir")) {
    ext.topsrcdir = file(buildscript.getSourceFile()).getParentFile().getParentFile().getParentFile().getParentFile().absolutePath
}

abstract class TopobjdirValueSource implements ValueSource<String, TopobjdirValueSource.Params> {
    interface Params extends ValueSourceParameters {
        Property<String> getTopsrcdir()
        Property<String> getMozconfigEnv()
        Property<String> getMozObjdirEnv()
        Property<String> getMozAutomation()
        Property<String> getMozconfigContents()
        Property<String> getDotMozconfigContents()
        Property<String> getDefaultMozconfigContents()
        Property<String> getLocalPropertiesContents()
        Property<String> getLocalMozconfigContents()
    }

    @Inject
    abstract ExecOperations getExecOperations()

    // Called when Gradle's configuration cache is invalidated. We maintain our own
    // local file cache here so that `./mach environment` only runs when inputs
    // actually change, not just when Gradle's config cache is wiped for other reasons.
    @Override
    String obtain() {
        def logger = org.gradle.api.logging.Logging.getLogger(TopobjdirValueSource.class)
        def topsrcdir = parameters.topsrcdir.get()

        // Compute hash of all inputs for local caching
        def inputs = new StringBuilder()
        inputs.append("MOZCONFIG=${parameters.mozconfigEnv.get()}\n")
        inputs.append("MOZ_OBJDIR=${parameters.mozObjdirEnv.get()}\n")
        inputs.append("mozconfigContents=${parameters.mozconfigContents.get().hashCode()}\n")
        inputs.append("dotMozconfigContents=${parameters.dotMozconfigContents.get().hashCode()}\n")
        inputs.append("defaultMozconfigContents=${parameters.defaultMozconfigContents.get().hashCode()}\n")
        inputs.append("localPropertiesContents=${parameters.localPropertiesContents.get().hashCode()}\n")
        inputs.append("localMozconfigContents=${parameters.localMozconfigContents.get().hashCode()}\n")

        logger.debug("mozconfig.gradle> Cache inputs:\n${inputs}")

        def sha256 = MessageDigest.getInstance("SHA-256")
        sha256.update(inputs.toString().getBytes(StandardCharsets.UTF_8))
        def currentHash = sha256.digest().encodeHex().toString()

        // Check local cache (this doesn't affect Gradle's config cache since we're inside obtain())
        // Disable local caching in automation to ensure consistent behavior
        def useCache = !parameters.mozAutomation.get()

        def cacheDir = new File(topsrcdir, ".gradle/mach-environment-cache")
        cacheDir.mkdirs()

        def cacheHashFile = new File(cacheDir, "inputs.sha256")
        def topobjdirCacheFile = new File(cacheDir, "topobjdir.txt")

        if (useCache && cacheHashFile.exists() && topobjdirCacheFile.exists()) {
            def cachedHash = cacheHashFile.text.trim()
            if (cachedHash == currentHash) {
                logger.debug("mozconfig.gradle> topobjdir cache hit!")
                return topobjdirCacheFile.text.trim()
            }
        }

        logger.debug("mozconfig.gradle> topobjdir cache miss! Running `./mach environment`")
        def command = ["${topsrcdir}/mach", "environment", "--format", "json"]
        if (System.properties["os.name"].contains("Windows")) {
            command.addAll(0, ["python"])
        }

        def stdout = new ByteArrayOutputStream()
        def stderr = new ByteArrayOutputStream()

        def result = execOperations.exec { spec ->
            spec.workingDir = new File(topsrcdir)
            spec.commandLine = command
            def mozconfigEnv = parameters.mozconfigEnv.get()
            if (mozconfigEnv) {
                spec.environment('MOZCONFIG', mozconfigEnv)
            }
            spec.standardOutput = stdout
            spec.errorOutput = stderr
            spec.ignoreExitValue = true
        }

        if (result.exitValue != 0) {
            throw new GradleException(
                "mozconfig.gradle> Error running ./mach environment:\n" +
                "Process '${command}' finished with non-zero exit value ${result.exitValue}:\n\n" +
                "stdout:\n${stdout}\n\n" +
                "stderr:\n${stderr}"
            )
        }

        def outputString = stdout.toString().normalize().trim()
        // Ignore possible lines of output from pip installing packages,
        // so only start at what looks like the beginning of a JSON object
        if (outputString.lastIndexOf("\n") != -1) {
            outputString = outputString.substring(outputString.lastIndexOf("\n") + 1).trim()
        }

        def slurper = new JsonSlurper()
        def jsonMachEnv
        try {
            jsonMachEnv = slurper.parseText(outputString)
        } catch (Exception e) {
            throw new GradleException("Failed to parse JSON from ./mach environment: ${e.message}\nOutput: ${outputString}")
        }

        def topobjdir = jsonMachEnv.topobjdir

        if (useCache) {
            try {
                cacheHashFile.text = currentHash
                topobjdirCacheFile.text = topobjdir
            } catch (Exception e) {
                logger.debug("mozconfig.gradle> Warning: Failed to write cache: ${e.message}")
            }
        }

        return topobjdir
    }
}

def readFileContents = { File f ->
    if (!f.exists() || f.isDirectory()) {
        return ""
    }
    return providers.fileContents(layout.rootDirectory.file(f.absolutePath)).asText.getOrElse("")
}

def mozObjdirEnv = providers.environmentVariable('MOZ_OBJDIR').getOrElse("")
def mozAutomation = providers.environmentVariable('MOZ_AUTOMATION').getOrElse("")

def dotMozconfigContents = readFileContents(new File(topsrcdir, '.mozconfig'))
def defaultMozconfigContents = readFileContents(new File(topsrcdir, 'mozconfig'))
def localPropertiesContents = readFileContents(new File(topsrcdir, 'local.properties'))

def localMozconfigResolvedPath = ""
def localMozconfigContents = ""
def localProperties = new Properties()
if (localPropertiesContents) {
    localProperties.load(new StringReader(localPropertiesContents))
    def localMozconfigProperty = localProperties.getProperty("mozilla-central.mozconfig")
    if (localMozconfigProperty) {
        def localMozconfigFile = new File(localMozconfigProperty).isAbsolute() ? new File(localMozconfigProperty) : new File(topsrcdir, localMozconfigProperty)
        localMozconfigResolvedPath = localMozconfigFile.absolutePath
        localMozconfigContents = readFileContents(localMozconfigFile)
    }
}

def mozconfigEnv = providers.environmentVariable('MOZCONFIG').getOrElse("")
if (mozconfigEnv && !new File(mozconfigEnv).isAbsolute()) {
    mozconfigEnv = new File(topsrcdir, mozconfigEnv).absolutePath
}
if (localMozconfigResolvedPath && (!mozconfigEnv || localMozconfigResolvedPath == mozconfigEnv)) {
    mozconfigEnv = localMozconfigResolvedPath
    logger.debug("mozconfig.gradle> Using mozconfig from local.properties: ${localMozconfigResolvedPath}")
} else if (localMozconfigResolvedPath) {
    logger.debug("mozconfig.gradle> Preferring mozconfig from environment over local.properties: ${mozconfigEnv}")
} else {
    logger.debug("mozconfig.gradle> No mozconfig found in local.properties")
}

def mozconfigFile = mozconfigEnv ? new File(mozconfigEnv) : null
def mozconfigContents = mozconfigFile ? readFileContents(mozconfigFile) : ""

// Extract autoPublish paths from local.properties for local substitution builds
["autoPublish.application-services.dir", "autoPublish.glean.dir"].each { key ->
    def relativeOrAbsolutePath = localProperties.getProperty(key)
    if (relativeOrAbsolutePath != null) {
        def autoPublishDir = new File(topsrcdir).toPath().resolve(relativeOrAbsolutePath)
        gradle.ext."localProperties.$key" = autoPublishDir.toString()
    }
}

def topsrcdirValue = topsrcdir
def mozconfigEnvValue = mozconfigEnv
def mozObjdirEnvValue = mozObjdirEnv
def mozAutomationValue = mozAutomation
def mozconfigContentsValue = mozconfigContents
def dotMozconfigContentsValue = dotMozconfigContents
def defaultMozconfigContentsValue = defaultMozconfigContents
def localPropertiesContentsValue = localPropertiesContents
def localMozconfigContentsValue = localMozconfigContents

def topobjdirProvider = providers.of(TopobjdirValueSource) {
    parameters {
        it.topsrcdir.set(topsrcdirValue)
        it.mozconfigEnv.set(mozconfigEnvValue)
        it.mozObjdirEnv.set(mozObjdirEnvValue)
        it.mozAutomation.set(mozAutomationValue)
        it.mozconfigContents.set(mozconfigContentsValue)
        it.dotMozconfigContents.set(dotMozconfigContentsValue)
        it.defaultMozconfigContents.set(defaultMozconfigContentsValue)
        it.localPropertiesContents.set(localPropertiesContentsValue)
        it.localMozconfigContents.set(localMozconfigContentsValue)
    }
}

def topobjdir = topobjdirProvider.get()
logger.debug("mozconfig.gradle> topobjdir=${topobjdir}")

def machEnvFile = new File(topobjdir, 'config.status.json')
if (!machEnvFile.exists()) {
    throw new GradleException("config.status.json not found at ${machEnvFile.absolutePath}. Run ./mach configure first.")
}

def slurper = new JsonSlurper()
def json
try {
    json = slurper.parse(machEnvFile)
} catch (Exception e) {
    logger.error("mozconfig.gradle> Failed to parse: ${machEnvFile.text}")
    throw new GradleException("Failed to parse ${machEnvFile.absolutePath}: ${e.message}")
}

def elapsed = System.currentTimeMillis() - startTime
logger.info("mozconfig.gradle> Loaded mach environment for ${topobjdir} in ${elapsed} ms")

if (json.substs.MOZ_BUILD_APP != 'mobile/android') {
    throw new GradleException("Building with Gradle is only supported for Firefox for Android, i.e., MOZ_BUILD_APP == 'mobile/android'.")
}

// The Gradle instance is shared between settings.gradle and all the
// other build.gradle files (see
// http://forums.gradle.org/gradle/topics/define_extension_properties_from_settings_xml).
// We use this ext property to pass the per-object-directory mozconfig
// between scripts.  This lets us execute set-up code before we gradle
// tries to configure the project even once, and as a side benefit
// saves invoking |mach environment| multiple times.
gradle.ext.mozconfig = json

// While we're here, read our VCS configuration when available.  This is usually
// present in the `mozconfig`, but the source of truth is `source-repo.h`, which
// incorporates environment variables after configure-time.
gradle.ext.mozconfig.source_repo = [:]
def sourceRepoFile = file("${gradle.mozconfig.topobjdir}/source-repo.h")
if (sourceRepoFile.canRead()) {
    def defines = ["MOZ_SOURCE_STAMP", "MOZ_SOURCE_REPO", "MOZ_SOURCE_URL"]

    sourceRepoFile.eachLine { line ->
        defines.forEach { define ->
            def matcher = line =~ ~/^#define ${define}\s(.*)/
            if (matcher.find()) {
                gradle.ext.mozconfig.source_repo[define] = matcher.group(1).trim()
            }
        }
    }

    if (gradle.ext.mozconfig.substs.MOZILLA_OFFICIAL) {
        logger.info("mozconfig.gradle> Parsed source-repo.h: ${gradle.ext.mozconfig.source_repo}");
    }
}

// Configures Maven repositories from mozconfig onto a RepositoryHandler.
// In Groovy, pass `delegate` from within a `repositories { }` closure, since
// `delegate` refers to the RepositoryHandler that receives method calls.
// In Kotlin, pass `this`.
gradle.ext.configureMavenRepositories = { handler ->
    gradle.mozconfig.substs.GRADLE_MAVEN_REPOSITORIES.each { repository ->
        handler.maven {
            url = repository
            if (gradle.mozconfig.substs.ALLOW_INSECURE_GRADLE_REPOSITORIES) {
                allowInsecureProtocol = true
            }
        }
    }
}