import {
  BookOpen,
  CircleDot,
  Files as FilesIcon,
  GitCommitHorizontal,
  GitPullRequest,
  Hash,
  RefreshCw,
  SquareTerminal,
  Users,
} from "lucide-react";
import * as React from "react";

import type {
  Project,
  ProjectLocalRepoSnapshot,
  ProjectPullRequest,
  ProjectPullRequestCommentAnchor,
  ProjectRepoContributor,
  ProjectRepoDiff,
  ProjectRepoSnapshot,
  Repository,
} from "@/features/projects/hooks";
import {
  commitAuthorPubkeysFromPullRequests,
  type ViewerGitIdentity,
} from "@/features/projects/lib/projectContributorMatching";
import { repositoryDiscussionQuery } from "@/features/projects/lib/discussionChannels";
import type { ProjectRepoHost } from "@/features/projects/lib/projectRepoHost";
import {
  projectRepoUnavailableReason,
  refineRepoUnavailableReason,
} from "@/features/projects/lib/projectRepoAvailability";
import { useMemberChannelIds } from "@/features/projects/useRepositoryAccess";
import type { UserProfileLookup } from "@/features/profile/lib/identity";
import { cn } from "@/shared/lib/cn";
import { Button } from "@/shared/ui/button";
import { Tabs, TabsContent } from "@/shared/ui/tabs";
import { findReadmeFile } from "./ProjectReadmePanel";
import { RepositoryFilesPanel } from "./ProjectRepositoryPanel";
import {
  type RepoSourceHeaderControls,
  RepoSourceDropdown,
  RepoSyncActionButton,
  RepositoryBranchDropdown,
} from "./ProjectRepositorySource";
import { DiscussionChannelsPanel } from "./DiscussionChannels";
import { ProjectCommitDetailPanel } from "./ProjectCommitDetailPanel";
import { ActivityPanel, ContributorsPanel } from "./ProjectDetailFeedPanels";
import { ProjectIssuesPanel } from "./ProjectIssuesPanel";
import type { OpenMergeRecoveryTerminal } from "./MergePullRequestButton";
import {
  type GitDataState,
  ProjectOverviewPanel,
} from "./ProjectOverviewPanel";
import {
  PullRequestDetailHeader,
  PullRequestMetaRail,
  PullRequestsPanel,
} from "./ProjectPullRequestsPanel";
import {
  ProjectTabsList,
  PullRequestTabsList,
} from "./ProjectWorkspaceTabList";
import { ProjectPullRequestFilesChangedPanel } from "./ProjectPullRequestFilesChangedPanel";
import {
  PROJECT_DETAIL_PANEL_CLASS,
  PROJECT_DETAIL_PANEL_MESSAGE_CLASS,
} from "./projectPanelStyles";
import { ProjectSectionHeader } from "./ProjectSectionHeader";
import { CreatePullRequestDialog } from "./CreatePullRequestDialog";
import {
  CreateIssueDialog,
  type CreateIssueDialogInput,
} from "./CreateIssueDialog";

type CreatePullRequestAction = {
  projects: Project[];
  reposDir?: string | null;
  onCreated: (
    project: Project,
    repository: Repository,
    pullRequestId: string,
  ) => void | Promise<void>;
};

type CreateIssueAction = {
  onCreate: (input: CreateIssueDialogInput) => Promise<void>;
  pending: boolean;
};

type UpdatePullRequestAction = {
  onUpdate: () => void;
  pending: boolean;
};

export function WorkspaceTabs({
  commitDiff,
  commitDiffError,
  commitDiffLoading,
  createIssueAction,
  createPullRequestAction,
  updatePullRequestAction,
  initialTab,
  initialTabRequestKey,
  localSnapshot,
  localSnapshotError,
  localSnapshotLoading,
  project,
  projectId,
  repoDiff,
  repoDiffError,
  repoDiffLoading,
  selectedCommitHash,
  selectedIssueId,
  selectedPullRequestId,
  pullRequests,
  pullRequestsError,
  pullRequestsLoading,
  onSelectedCommitHashChange,
  onSelectedIssueIdChange,
  onSelectedPullRequestIdChange,
  onSelectedTabChange,
  onBranchChange,
  onOpenMergeRecoveryTerminal,
  onOpenTerminal,
  snapshot,
  snapshotError,
  snapshotLoading,
  profiles,
  repoContributors,
  repoSource,
  repoHost,
  repositoryControls,
  sourceControls,
  terminalTitle,
  viewerGitIdentity,
}: {
  commitDiff: ProjectRepoDiff | null | undefined;
  commitDiffError: unknown;
  commitDiffLoading: boolean;
  createIssueAction: CreateIssueAction;
  createPullRequestAction?: CreatePullRequestAction;
  updatePullRequestAction?: UpdatePullRequestAction;
  /** Tab to open on mount (workspace vocabulary), e.g. from a share link. */
  initialTab?: string;
  /** Changes for every entity-link activation, including repeated links. */
  initialTabRequestKey?: string;
  localSnapshot: ProjectLocalRepoSnapshot | null | undefined;
  localSnapshotError: unknown;
  localSnapshotLoading: boolean;
  project: Repository;
  projectId: string;
  repoDiff: ProjectRepoDiff | null | undefined;
  repoDiffError: unknown;
  repoDiffLoading: boolean;
  selectedCommitHash: string | null;
  selectedIssueId: string | null;
  selectedPullRequestId: string | null;
  pullRequests: ProjectPullRequest[];
  pullRequestsError: unknown;
  pullRequestsLoading: boolean;
  onSelectedCommitHashChange: (hash: string | null) => void;
  onSelectedIssueIdChange: (id: string | null) => void;
  onSelectedPullRequestIdChange: (id: string | null) => void;
  /** Reports the active tab so the screen breadcrumb can mirror it. */
  onSelectedTabChange?: (tab: string) => void;
  onBranchChange: (branch: string | null) => void;
  onOpenMergeRecoveryTerminal?: OpenMergeRecoveryTerminal;
  onOpenTerminal?: () => void;
  snapshot: ProjectRepoSnapshot | null | undefined;
  snapshotError: unknown;
  snapshotLoading: boolean;
  profiles?: UserProfileLookup;
  repoContributors: ProjectRepoContributor[];
  repoSource: "remote" | "local";
  repoHost: ProjectRepoHost;
  /** Repository picker (and related actions) for the selection header row. */
  repositoryControls?: React.ReactNode;
  /** Branch picker + remote/local toggle for the selection header row. */
  sourceControls?: RepoSourceHeaderControls;
  terminalTitle?: string;
  viewerGitIdentity?: ViewerGitIdentity | null;
}) {
  const localCheckoutSnapshot = localSnapshot?.snapshot ?? null;
  const displayedSnapshot =
    repoSource === "local" ? localCheckoutSnapshot : snapshot;
  const displayedSnapshotError =
    repoSource === "local" ? localSnapshotError : snapshotError;
  const displayedSnapshotLoading =
    repoSource === "local" ? localSnapshotLoading : snapshotLoading;
  const displayedContributors =
    displayedSnapshot?.contributors ?? repoContributors;
  const files = displayedSnapshot?.files ?? [];
  const readmeFile = React.useMemo(() => findReadmeFile(files), [files]);
  const externalHost =
    repoSource === "remote" && repoHost.kind === "external"
      ? repoHost.host
      : undefined;
  const gitDataState: GitDataState = displayedSnapshotLoading
    ? "checking"
    : externalHost || displayedSnapshotError || !displayedSnapshot
      ? "unavailable"
      : files.length === 0
        ? "empty"
        : "available";
  // The relay masks channel-ACL denials as 404 (anti-enumeration), so a
  // "missing" git result is re-classified with the repository's channel
  // binding and the viewer's memberships before it reaches the UI copy.
  const memberChannelIds = useMemberChannelIds();
  const unavailableReason =
    gitDataState === "unavailable" && !externalHost
      ? refineRepoUnavailableReason({
          reason: projectRepoUnavailableReason(displayedSnapshotError),
          repositoryChannelId: project.channelId,
          memberChannelIds,
        })
      : undefined;
  const repositoryLoaded =
    gitDataState === "available" || gitDataState === "empty";
  const commitAuthorPubkeys = React.useMemo(
    () => commitAuthorPubkeysFromPullRequests(pullRequests),
    [pullRequests],
  );
  const selectedPullRequest =
    pullRequests.find(
      (pullRequest) => pullRequest.id === selectedPullRequestId,
    ) ?? null;
  const selectedCommitPullRequest = React.useMemo(
    () =>
      pullRequests.find(
        (pullRequest) =>
          pullRequest.commit === selectedCommitHash ||
          pullRequest.initialCommit === selectedCommitHash,
      ),
    [pullRequests, selectedCommitHash],
  );
  const isPullRequestSelected = Boolean(selectedPullRequest);
  const isDetailSelected = Boolean(
    selectedPullRequestId || selectedIssueId || selectedCommitHash,
  );
  const [selectedTab, setSelectedTab] = React.useState(
    initialTab ?? "overview",
  );
  // Follow later share-link navigations to the same project (the search
  // param changes without a remount).
  // biome-ignore lint/correctness/useExhaustiveDependencies: request key intentionally retriggers an unchanged tab.
  React.useEffect(() => {
    if (initialTab) setSelectedTab(initialTab);
  }, [initialTab, initialTabRequestKey]);
  const [pullRequestCommentTarget, setPullRequestCommentTarget] =
    React.useState<{
      anchor: ProjectPullRequestCommentAnchor;
      pullRequestId: string;
    } | null>(null);
  const [createIssueOpen, setCreateIssueOpen] = React.useState(false);
  const [createPullRequestOpen, setCreatePullRequestOpen] =
    React.useState(false);

  React.useEffect(() => {
    onSelectedTabChange?.(selectedTab);
  }, [onSelectedTabChange, selectedTab]);

  React.useEffect(() => {
    if (isPullRequestSelected) {
      setSelectedTab((currentTab) =>
        currentTab.startsWith("pr-") ? currentTab : "pr-conversation",
      );
      if (selectedPullRequest?.branchName) {
        onBranchChange(selectedPullRequest.branchName);
      }
    } else {
      setSelectedTab((currentTab) =>
        currentTab.startsWith("pr-") ? "prs" : currentTab,
      );
    }
  }, [isPullRequestSelected, onBranchChange, selectedPullRequest?.branchName]);

  React.useEffect(() => {
    if (selectedIssueId) {
      setSelectedTab("issues");
    }
  }, [selectedIssueId]);

  React.useEffect(() => {
    if (selectedCommitHash) {
      setSelectedTab("activity");
    }
  }, [selectedCommitHash]);

  const handleTabChange = React.useCallback(
    (nextTab: string) => {
      setSelectedTab(nextTab);
      if (!nextTab.startsWith("pr-")) {
        onSelectedPullRequestIdChange(null);
      }
      if (nextTab !== "issues") {
        onSelectedIssueIdChange(null);
      }
      if (nextTab !== "activity") {
        onSelectedCommitHashChange(null);
      }
    },
    [
      onSelectedCommitHashChange,
      onSelectedIssueIdChange,
      onSelectedPullRequestIdChange,
    ],
  );
  const handleOpenPullRequestComment = React.useCallback(
    (anchor: ProjectPullRequestCommentAnchor) => {
      if (!selectedPullRequestId) return;
      setPullRequestCommentTarget({
        anchor: { ...anchor },
        pullRequestId: selectedPullRequestId,
      });
      setSelectedTab("pr-files");
    },
    [selectedPullRequestId],
  );
  const showRepositorySelection =
    selectedTab === "overview" || selectedTab === "files";
  const sectionHeader =
    selectedTab === "overview" ? (
      <ProjectSectionHeader icon={BookOpen} title="README" />
    ) : selectedTab === "files" ? (
      <ProjectSectionHeader icon={FilesIcon} title="Files" />
    ) : selectedTab === "activity" && !selectedCommitHash ? (
      <ProjectSectionHeader icon={GitCommitHorizontal} title="Commits" />
    ) : selectedTab === "issues" && !selectedIssueId ? (
      <ProjectSectionHeader
        action={{
          disabled: createIssueAction.pending,
          label: "New issue",
          onClick: () => setCreateIssueOpen(true),
        }}
        icon={CircleDot}
        title="Issues"
      />
    ) : selectedTab === "prs" ? (
      <ProjectSectionHeader
        action={{
          disabled:
            !createPullRequestAction ||
            createPullRequestAction.projects.length === 0,
          label: "New pull request",
          onClick: () => setCreatePullRequestOpen(true),
          title:
            "New pull request — choose a repository and branches to compare",
        }}
        icon={GitPullRequest}
        title="Pull Requests"
      />
    ) : selectedTab === "channels" ? (
      <ProjectSectionHeader icon={Hash} title="Channels" />
    ) : selectedTab === "contributors" ? (
      <ProjectSectionHeader icon={Users} title="Contributors" />
    ) : null;

  return (
    <Tabs
      className="min-w-0 space-y-3"
      onValueChange={handleTabChange}
      value={selectedTab}
    >
      {repositoryLoaded && !isDetailSelected ? (
        <div
          className="flex h-10 min-w-0 items-center gap-1"
          data-testid="project-workspace-tab-menu"
        >
          <ProjectTabsList prsActive={isPullRequestSelected} />
          {onOpenTerminal ? (
            <Button
              aria-label="Open terminal"
              className="h-8 w-8 shrink-0 text-muted-foreground hover:text-foreground"
              onClick={() => onOpenTerminal()}
              size="icon"
              title={terminalTitle ?? "Open terminal"}
              variant="ghost"
            >
              <SquareTerminal className="h-[1.125rem] w-[1.125rem]" />
            </Button>
          ) : null}
          {updatePullRequestAction ? (
            <Button
              className="h-8 shrink-0 gap-1.5"
              disabled={updatePullRequestAction.pending}
              onClick={updatePullRequestAction.onUpdate}
              size="sm"
              title="Publish the pushed commit to this pull request"
              variant="outline"
            >
              <RefreshCw className="h-4 w-4" />
              {updatePullRequestAction.pending ? "Updating…" : "Update PR"}
            </Button>
          ) : null}
        </div>
      ) : null}
      {/* The bordered workspace starts with repository / source / branch
          controls only for README and Files, then the active panel. Inner
          panels retain standalone chrome, neutralized here. */}
      <div
        className={cn(
          PROJECT_DETAIL_PANEL_CLASS,
          "[&_[data-project-detail-panel]]:rounded-none [&_[data-project-detail-panel]]:border-0",
        )}
        data-project-detail-panel
        data-testid="project-workspace-panel"
      >
        {showRepositorySelection && (repositoryControls || sourceControls) ? (
          <div
            className="flex min-h-12 min-w-0 flex-wrap items-center gap-1.5 border-border/50 border-b px-3 py-2"
            data-testid="project-repository-selection-row"
          >
            {repositoryControls}
            {sourceControls ? (
              <>
                <RepoSourceDropdown controls={sourceControls} />
                <RepositoryBranchDropdown
                  branch={sourceControls.branch}
                  branchOptions={sourceControls.branchOptions}
                  createBranchDisabled={sourceControls.createBranchDisabled}
                  createBranchTitle={sourceControls.createBranchTitle}
                  deleteBranchDisabled={sourceControls.deleteBranchDisabled}
                  deleteBranchTitle={sourceControls.deleteBranchTitle}
                  onBranchChange={sourceControls.onBranchChange}
                  onCreateBranch={sourceControls.onCreateBranch}
                  onDeleteBranch={sourceControls.onDeleteBranch}
                  onTagChange={sourceControls.onTagChange}
                  selectedTag={sourceControls.selectedTag}
                  tagOptions={sourceControls.tagOptions}
                />
                <div className="ml-auto flex shrink-0 items-center">
                  <RepoSyncActionButton controls={sourceControls} />
                </div>
              </>
            ) : null}
          </div>
        ) : null}
        {sectionHeader}
        {selectedPullRequest ? (
          <div className={PROJECT_DETAIL_PANEL_CLASS} data-project-detail-panel>
            {/* Two full-height columns: the meta rail runs all the way to the
              top of the card, alongside the header and tabs. */}
            <div className="grid xl:grid-cols-[minmax(0,1fr)_18rem]">
              <div className="min-w-0">
                <PullRequestDetailHeader
                  profiles={profiles}
                  pullRequest={selectedPullRequest}
                />
                <div className="border-b border-border/60 px-4">
                  <PullRequestTabsList
                    filesCount={repoDiff?.files.length ?? files.length}
                    pullRequest={selectedPullRequest}
                  />
                </div>
                {(["conversation", "commits", "checks"] as const).map(
                  (mode) => (
                    <TabsContent
                      className="m-0"
                      key={mode}
                      value={`pr-${mode}`}
                    >
                      <PullRequestsPanel
                        error={pullRequestsError}
                        isLoading={pullRequestsLoading}
                        mode={mode}
                        onOpenInlineComment={handleOpenPullRequestComment}
                        onOpenCommit={onSelectedCommitHashChange}
                        onOpenTerminal={onOpenMergeRecoveryTerminal}
                        onSelectedPullRequestIdChange={
                          onSelectedPullRequestIdChange
                        }
                        profiles={profiles}
                        project={project}
                        pullRequests={pullRequests}
                        selectedPullRequestId={selectedPullRequestId}
                      />
                    </TabsContent>
                  ),
                )}
                <TabsContent className="m-0" value="pr-files">
                  <ProjectPullRequestFilesChangedPanel
                    diff={repoDiff}
                    error={repoDiffError}
                    focusedAnchor={
                      pullRequestCommentTarget?.pullRequestId ===
                      selectedPullRequestId
                        ? pullRequestCommentTarget.anchor
                        : null
                    }
                    isLoading={repoDiffLoading}
                    profiles={profiles}
                    project={project}
                    pullRequest={selectedPullRequest}
                  />
                </TabsContent>
              </div>
              <PullRequestMetaRail
                profiles={profiles}
                project={project}
                pullRequest={selectedPullRequest}
              />
            </div>
          </div>
        ) : null}

        <TabsContent className="m-0" value="overview">
          <ProjectOverviewPanel
            accessChannelId={project.channelId}
            contributors={displayedContributors}
            externalHost={externalHost}
            externalUrl={externalHost ? sourceControls?.externalUrl : null}
            files={files}
            gitDataState={gitDataState}
            hideReadmeHeader
            onViewContributors={() => setSelectedTab("contributors")}
            profiles={profiles}
            project={project}
            pullRequests={pullRequests}
            readmeFile={readmeFile}
            snapshot={displayedSnapshot}
            sourceControls={sourceControls}
            unavailableReason={unavailableReason}
          />
        </TabsContent>

        <TabsContent className="m-0" value="activity">
          {selectedCommitHash ? (
            <ProjectCommitDetailPanel
              commit={
                displayedSnapshot?.commits.find(
                  (commit) => commit.hash === selectedCommitHash,
                ) ?? null
              }
              commitAuthorPubkeys={commitAuthorPubkeys}
              commitHash={selectedCommitHash}
              viewerGitIdentity={viewerGitIdentity}
              diff={commitDiff}
              diffError={commitDiffError}
              diffLoading={commitDiffLoading}
              originAgentName={selectedCommitPullRequest?.originAgentName}
              originChannelId={selectedCommitPullRequest?.channelId}
              profiles={profiles}
            />
          ) : (
            <ActivityPanel
              branch={sourceControls?.branch}
              error={displayedSnapshotError}
              isLoading={displayedSnapshotLoading}
              onSelectCommit={(commit) =>
                onSelectedCommitHashChange(commit.hash)
              }
              profiles={profiles}
              pullRequests={pullRequests}
              repoContributors={displayedContributors}
              snapshot={displayedSnapshot}
              viewerGitIdentity={viewerGitIdentity}
            />
          )}
        </TabsContent>

        <TabsContent
          className={`m-0 ${PROJECT_DETAIL_PANEL_CLASS}`}
          data-project-detail-panel
          value="prs"
        >
          <PullRequestsPanel
            error={pullRequestsError}
            isLoading={pullRequestsLoading}
            onOpenCommit={onSelectedCommitHashChange}
            onOpenTerminal={onOpenMergeRecoveryTerminal}
            onSelectedPullRequestIdChange={onSelectedPullRequestIdChange}
            profiles={profiles}
            project={project}
            pullRequests={pullRequests}
            selectedPullRequestId={selectedPullRequestId}
          />
        </TabsContent>

        <TabsContent
          className={`m-0 ${PROJECT_DETAIL_PANEL_CLASS}`}
          data-project-detail-panel
          value="issues"
        >
          <ProjectIssuesPanel
            onSelectedIssueIdChange={onSelectedIssueIdChange}
            profiles={profiles}
            project={project}
            selectedIssueId={selectedIssueId}
          />
        </TabsContent>

        <TabsContent className="m-0" value="files">
          {repoSource === "local" && !localSnapshot && !localSnapshotLoading ? (
            <div className="mb-3">
              <div
                className={PROJECT_DETAIL_PANEL_MESSAGE_CLASS}
                data-project-detail-panel
              >
                No local checkout found.
              </div>
            </div>
          ) : null}
          <RepositoryFilesPanel
            error={displayedSnapshotError}
            fallbackAuthorPubkey={project.owner}
            files={files}
            isLoading={displayedSnapshotLoading}
            profiles={profiles}
            snapshot={displayedSnapshot}
            unavailableMessage={
              externalHost
                ? `Not mirrored on Buzz. Repository files are hosted on ${externalHost}.`
                : undefined
            }
          />
        </TabsContent>

        <TabsContent className="m-0" value="channels">
          <DiscussionChannelsPanel query={repositoryDiscussionQuery(project)} />
        </TabsContent>

        <TabsContent className="m-0" value="contributors">
          <ContributorsPanel
            profiles={profiles}
            repoContributors={displayedContributors}
          />
        </TabsContent>
      </div>
      {createPullRequestAction && createPullRequestOpen ? (
        <CreatePullRequestDialog
          initialProjectId={projectId}
          onCreated={createPullRequestAction.onCreated}
          onOpenChange={setCreatePullRequestOpen}
          open
          projects={createPullRequestAction.projects}
          reposDir={createPullRequestAction.reposDir}
        />
      ) : null}
      <CreateIssueDialog
        isCreating={createIssueAction.pending}
        onCreate={createIssueAction.onCreate}
        onOpenChange={setCreateIssueOpen}
        open={createIssueOpen}
        projectName={project.name}
      />
    </Tabs>
  );
}