# -----------------------------------------------------------------------------
# Copyright (C) 2026 Iliyas Jorio.
# This file is part of GitFourchette, distributed under the GNU GPL v3.
# For full terms, see the included LICENSE file.
# -----------------------------------------------------------------------------

from __future__ import annotations  # TODO: Remove once we can drop support for Python <= 3.13

from typing import ClassVar

from gitfourchette.application import GFApplication
from gitfourchette.blameview.blamemodel import BlameModel, Revision
from gitfourchette.blameview.blamescrubber import BlameScrubber
from gitfourchette.blameview.blametextedit import BlameTextEdit
from gitfourchette.blameview.blamebusyspinner import BlameBusySpinner
from gitfourchette.graphview.commitlogmodel import CommitLogModel
from gitfourchette.localization import *
from gitfourchette.nav import NavLocator, NavHistory, NavFlags
from gitfourchette.qt import *
from gitfourchette.tasks import RepoTaskRunner
from gitfourchette.toolbox import *


class BlameWindow(QWidget):
    exploreCommit = Signal(NavLocator)

    _currentBlameWindows: ClassVar[list[BlameWindow]] = []
    "Currently open BlameWindows"

    def __init__(self, blameModel: BlameModel):
        # DON'T parent the window so it doesn't sit on top of MainWindow on Wayland
        super().__init__(None)

        # Keep reference around to avoid being GC'd instantly
        BlameWindow._currentBlameWindows.append(self)

        self.setObjectName("BlameWindow")

        self.model = blameModel
        self.taskRunner = RepoTaskRunner(self)
        self.navHistory = NavHistory()

        self.textEdit = BlameTextEdit(blameModel, self)
        self.textEdit.setUpAsDetachedWindow()

        self.scrubber = BlameScrubber(blameModel, self)
        self.scrubber.activated.connect(self.onScrubberActivated)

        self.jumpButton = QToolButton()
        self.jumpButton.setText(_("Jump"))
        self.jumpButton.setToolTip(_("View this commit in the repo"))
        self.jumpButton.setIcon(stockIcon("go-window@20px"))
        self.jumpButton.clicked.connect(lambda: self.jumpToCommit())

        oldNewTipTemplate = (f"<p style='white-space: pre'>{{0}}<br>"
                             f"<span style='color: {mutedToolTipColorHex()}'>({_('Shift+Click:')} {{1}})</span>")

        self.olderButton = QToolButton()
        self.olderButton.setText(_("Older"))
        self.olderButton.clicked.connect(self.goOlder)
        self.olderButton.setToolTip(oldNewTipTemplate.format(_("Go to next older revision"), _("Jump to bottom")))
        self.olderButton.setIcon(stockIcon("go-older"))

        self.newerButton = QToolButton()
        self.newerButton.setText(_("Newer"))
        self.newerButton.clicked.connect(self.goNewer)
        self.newerButton.setToolTip(oldNewTipTemplate.format(_("Go to next newer revision"), _("Jump to top")))
        self.newerButton.setIcon(stockIcon("go-newer"))

        self.backButton = QToolButton()
        self.backButton.setText(_("Back"))
        self.backButton.clicked.connect(self.goBack)
        self.backButton.setToolTip(_("Navigate back"))
        self.backButton.setIcon(stockIcon("back"))

        self.forwardButton = QToolButton()
        self.forwardButton.setText(_("Forward"))
        self.forwardButton.clicked.connect(self.goForward)
        self.forwardButton.setToolTip(_("Navigate forward"))
        self.forwardButton.setIcon(stockIcon("forward"))

        topBar = QToolBar()
        topBar.setIconSize(QSize(20, 20))
        topBar.addWidget(self.backButton)
        topBar.addWidget(self.forwardButton)
        topBar.addSeparator()
        topBar.addWidget(self.newerButton)
        topBar.addWidget(self.olderButton)
        topBar.addWidget(self.scrubber)
        topBar.addWidget(self.jumpButton)
        layout = QVBoxLayout(self)
        layout.setContentsMargins(QMargins())
        layout.addWidget(topBar)
        layout.addWidget(self.textEdit.searchBar)
        layout.addWidget(self.textEdit)
        layout.setSpacing(0)

        self.textEdit.showRevision.connect(self.showRevision)
        self.textEdit.jumpToCommit.connect(self.jumpToCommit)

        self.setWindowModality(Qt.WindowModality.NonModal)
        self.setWindowFlags(Qt.WindowType.Window)
        self.setAttribute(Qt.WidgetAttribute.WA_DeleteOnClose)

        self.busySpinner = BlameBusySpinner(self.textEdit)
        self.textEdit.sizeChanged.connect(self.busySpinner.reposition)

        app = GFApplication.instance()
        app.mouseSideButtonPressed.connect(self.onMouseSideButtonPressed)

    # -------------------------------------------------------------------------
    # Event filters & handlers

    def onMouseSideButtonPressed(self, forward: bool):
        if not self.isActiveWindow():
            return
        delta = [-1, 1][forward]
        self.goBackOrForwardDelta(delta)

    def closeEvent(self, event: QCloseEvent):
        assert self in self._currentBlameWindows
        self._currentBlameWindows.remove(self)

        self.scrubber.scrubberDelegate.prepareForDeletion()
        self.scrubber.deleteLater()

        self.taskRunner.prepareForDeletion()
        self.model.prepareForDeletion()

        super().closeEvent(event)

    # -------------------------------------------------------------------------

    def saveFilePosition(self) -> NavLocator:
        currentLocator = self.textEdit.preciseLocator()
        self.navHistory.push(currentLocator)
        return currentLocator

    def showRevision(self, revision: Revision, saveAndTransposePosition=True):
        from gitfourchette.tasks.blametasks import BlameRevision
        BlameRevision.invoke(self, revision, saveAndTransposePosition)

    def syncNavButtons(self):
        index = self.scrubber.currentIndex()
        count = self.scrubber.count()

        self.newerButton.setEnabled(index != 0 and count >= 2)
        self.olderButton.setEnabled(index != count - 1)

        self.backButton.setEnabled(self.navHistory.canGoBack())
        self.forwardButton.setEnabled(self.navHistory.canGoForward())

    def goNewer(self):
        if QGuiApplication.keyboardModifiers() == Qt.KeyboardModifier.ShiftModifier:
            topRevision = self.model.revList.sequence[0]
            self.showRevision(topRevision)
        else:
            self.goNewerOrOlder(-1)

    def goOlder(self):
        if QGuiApplication.keyboardModifiers() == Qt.KeyboardModifier.ShiftModifier:
            bottomRevision = self.model.revList.sequence[-1]
            self.showRevision(bottomRevision)
        else:
            self.goNewerOrOlder(1)

    def goBack(self):
        self.goBackOrForwardDelta(-1)

    def goForward(self):
        self.goBackOrForwardDelta(1)

    def goNewerOrOlder(self, delta: int):
        index = self.scrubber.currentIndex()
        index += delta
        assert 0 <= index < self.scrubber.count()
        revision = self.getRevisionFromScrubberRow(index)
        self.showRevision(revision)

    def goBackOrForwardDelta(self, delta: int):
        self.saveFilePosition()
        locator = self.navHistory.navigateDelta(delta)
        if not locator:
            return
        revision = self.model.revList.revisionForCommit(locator.commit)
        self.showRevision(revision, saveAndTransposePosition=False)

    def onScrubberActivated(self, index: int):
        revision = self.getRevisionFromScrubberRow(index)
        self.showRevision(revision)

    def getRevisionFromScrubberRow(self, index: int) -> Revision:
        return self.scrubber.itemData(index, CommitLogModel.Role.BlameRevision)

    def jumpToCommit(self, locator: NavLocator = NavLocator.Empty):
        if locator == NavLocator.Empty:
            locator = self.model.currentRevision.toLocator()
        locator = locator.withExtraFlags(NavFlags.ActivateWindow)
        self.exploreCommit.emit(locator)
