package org.jetbrains.dokka.allModulesPage

import org.jetbrains.dokka.allModulesPage.MultimodulePageCreator.Companion.MULTIMODULE_PACKAGE_PLACEHOLDER
import org.jetbrains.dokka.base.DokkaBase
import org.jetbrains.dokka.base.resolvers.local.DokkaBaseLocationProvider
import org.jetbrains.dokka.base.resolvers.local.LocationProviderFactory
import org.jetbrains.dokka.links.DRI
import org.jetbrains.dokka.model.DisplaySourceSet
import org.jetbrains.dokka.pages.PageNode
import org.jetbrains.dokka.pages.RootPageNode
import org.jetbrains.dokka.plugability.DokkaContext
import org.jetbrains.dokka.plugability.plugin
import org.jetbrains.dokka.plugability.querySingle

open class MultimoduleLocationProvider(private val root: RootPageNode, dokkaContext: DokkaContext) : DokkaBaseLocationProvider(root, dokkaContext) {

    private val defaultLocationProvider = dokkaContext.plugin<AllModulesPagePlugin>().querySingle { partialLocationProviderFactory }.getLocationProvider(root)
    private val externalModuleLinkResolver = dokkaContext.plugin<AllModulesPagePlugin>().querySingle { externalModuleLinkResolver }

    override fun resolve(dri: DRI, sourceSets: Set<DisplaySourceSet>, context: PageNode?) =
            if (dri == MultimodulePageCreator.MULTIMODULE_ROOT_DRI) pathToRoot(root)
            else dri.takeIf { it.packageName == MULTIMODULE_PACKAGE_PLACEHOLDER }?.classNames
                        ?.let(externalModuleLinkResolver::resolveLinkToModuleIndex)

    override fun resolve(node: PageNode, context: PageNode?, skipExtension: Boolean) =
            defaultLocationProvider.resolve(node, context, skipExtension)

    override fun pathToRoot(from: PageNode): String = defaultLocationProvider.pathToRoot(from)

    override fun ancestors(node: PageNode): List<PageNode> = listOf(root)

    class Factory(private val context: DokkaContext) : LocationProviderFactory {
        override fun getLocationProvider(pageNode: RootPageNode) =
                MultimoduleLocationProvider(pageNode, context)
    }
}