package org.iwakura.larcjb.widget

import com.intellij.openapi.project.Project
import com.intellij.openapi.util.Disposer
import com.intellij.openapi.vcs.ProjectLevelVcsManager
import com.intellij.openapi.vfs.VirtualFile
import com.intellij.openapi.wm.StatusBar
import com.intellij.openapi.wm.StatusBarWidget
import com.intellij.openapi.wm.StatusBarWidgetFactory
import com.intellij.util.Consumer
import org.iwakura.larcjb.LarcExecutable
import org.iwakura.larcjb.LarcVcs
import java.awt.event.MouseEvent

/**
 * Status bar widget showing current Larc branch.
 */
class LarcBranchWidgetFactory : StatusBarWidgetFactory {

    override fun getId(): String = WIDGET_ID

    override fun getDisplayName(): String = "Larc Branch"

    override fun isAvailable(project: Project): Boolean {
        return ProjectLevelVcsManager.getInstance(project)
            .allVcsRoots
            .any { it.vcs?.name == LarcVcs.NAME }
    }

    override fun createWidget(project: Project): StatusBarWidget {
        return LarcBranchWidget(project)
    }

    override fun canBeEnabledOn(statusBar: StatusBar): Boolean = true

    companion object {
        const val WIDGET_ID = "LarcBranchWidget"
    }
}

class LarcBranchWidget(private val project: Project) : StatusBarWidget, StatusBarWidget.TextPresentation {

    private var statusBar: StatusBar? = null
    private var currentBranch: String? = null

    override fun ID(): String = LarcBranchWidgetFactory.WIDGET_ID

    override fun getPresentation(): StatusBarWidget.WidgetPresentation = this

    override fun install(statusBar: StatusBar) {
        this.statusBar = statusBar
        updateBranch()
    }

    override fun dispose() {
        statusBar = null
    }

    override fun getText(): String {
        return currentBranch?.let { "Larc: $it" } ?: ""
    }

    override fun getTooltipText(): String = "Current Larc branch"

    override fun getAlignment(): Float = 0f

    override fun getClickConsumer(): Consumer<MouseEvent>? {
        return Consumer {
            /* TODO(kroot): show branch selector popup */
            updateBranch()
        }
    }

    fun updateBranch() {
        val roots = getLarcRoots()
        if (roots.isEmpty()) {
            currentBranch = null
            return
        }

        val executable = LarcExecutable(project)
        currentBranch = executable.currentBranch(roots.first())

        statusBar?.updateWidget(ID())
    }

    private fun getLarcRoots(): List<VirtualFile> {
        return ProjectLevelVcsManager.getInstance(project)
            .allVcsRoots
            .filter { it.vcs?.name == LarcVcs.NAME }
            .mapNotNull { it.path }
    }
}