import { useMemo, useState } from "react";
import { useQuery } from "@tanstack/react-query";
import { AlertCircle, CheckCircle2, ClipboardCheck, Download, FlaskConical, GitPullRequest, Upload, X } from "lucide-react";
import {
  asWorkspaceApiError,
  exportWorkspace,
  getWorkspace,
  getWorkspaceRegistryStatus,
  importWorkspace,
  listWorkspaces,
  pullWorkspaceRegistry,
  testWorkspace,
  validateWorkspace,
  type CanonicalWorkspace,
  type PublishWorkspaceRequest,
  type WorkspaceRecord,
  type WorkspaceSummary,
} from "../api/workspaces";
import { workspaceBootstrapDrafts, type WorkspaceBootstrapDraft } from "../workspaces/drafts";
import { Button } from "../components/ui/button";
import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from "../components/ui/dialog";
import { WorkspaceEditor } from "./WorkspaceEditor";
import { WorkspacePublishDialog } from "./WorkspacePublishDialog";

const EMPTY_COMMIT = "0".repeat(40);

function QueryError({ name, message, retryLabel, onRetry }: {
  name: string;
  message: string;
  retryLabel: string;
  onRetry: () => void;
}) {
  return <div role="alert" aria-label={name} className="grid gap-2 rounded-md border border-destructive/30 bg-destructive/5 p-3 text-sm"><p>{message}</p><div><Button size="sm" variant="outline" onClick={onRetry}>{retryLabel}</Button></div></div>;
}

function defaultBootstrapWorkspace(summary: WorkspaceSummary): CanonicalWorkspace {
  return {
    workspace: {
      schema_version: 3,
      id: summary.id,
      name: summary.displayName,
      ...(summary.description ? { description: summary.description } : {}),
      language: "en",
    },
    dwh: {
      engine: "postgres",
      database: "database",
      schema: "public",
      supported_transports: ["postgres_direct"],
    },
    semantic_index: {
      vector_store: {
        engine: "qdrant",
        collection: summary.id.replaceAll("-", "_"),
        dimensions: 1024,
        distance: "cosine",
      },
      embedding: {
        provider: "ollama_internal",
        model: "qwen3-embedding:0.6b",
        dimensions: 1024,
      },
    },
    llm_policy: { allowed: ["zai/glm-5.2"], default: "zai/glm-5.2" },
  };
}

function bootstrapDraftFor(summary: WorkspaceSummary, baseCommit: string): WorkspaceBootstrapDraft {
  return {
    workspaceId: summary.id,
    baseCommit,
    workspace: defaultBootstrapWorkspace(summary),
    updatedAt: new Date().toISOString(),
  };
}

export function WorkspaceManager({ open, onClose }: { open: boolean; onClose: () => void }) {
  const [selectedId, setSelectedId] = useState<string>();
  const [localDraft, setLocalDraft] = useState<WorkspaceBootstrapDraft>();
  const [notice, setNotice] = useState<string>();
  const [diagnostics, setDiagnostics] = useState<string[]>([]);
  const [publishRequest, setPublishRequest] = useState<PublishWorkspaceRequest>();
  const [transferring, setTransferring] = useState(false);

  const statusQuery = useQuery({ queryKey: ["workspace-registry-status"], queryFn: getWorkspaceRegistryStatus, enabled: open });
  const workspacesQuery = useQuery({ queryKey: ["workspaces"], queryFn: listWorkspaces, enabled: open });
  const workspaces = workspacesQuery.data ?? [];
  const selectedSummary = useMemo(() => workspaces.find((workspace) => workspace.id === selectedId), [selectedId, workspaces]);
  const detailQuery = useQuery({
    queryKey: ["workspace", selectedId],
    queryFn: () => getWorkspace(selectedId!),
    enabled: Boolean(open && selectedId && selectedSummary?.configurationState === "ready"),
  });
  const record = detailQuery.data;

  const activeBootstrapDraft = selectedSummary?.configurationState === "configuration_required"
    ? (localDraft?.workspaceId === selectedSummary.id ? localDraft : workspaceBootstrapDrafts.load(selectedSummary.id) ?? bootstrapDraftFor(selectedSummary, statusQuery.data?.head ?? EMPTY_COMMIT))
    : undefined;

  function resetTransientState() {
    setNotice(undefined);
    setDiagnostics([]);
    setPublishRequest(undefined);
  }

  function selectWorkspace(id: string) {
    setSelectedId(id);
    setLocalDraft(undefined);
    resetTransientState();
  }

  function saveDraft(draft: WorkspaceBootstrapDraft) {
    workspaceBootstrapDrafts.save(draft);
    setLocalDraft(draft);
    setSelectedId(draft.workspaceId);
    setNotice("Draft saved in this browser.");
    setDiagnostics([]);
  }

  function requestCreate(request: PublishWorkspaceRequest, draft: WorkspaceBootstrapDraft) {
    workspaceBootstrapDrafts.save(draft);
    setLocalDraft(draft);
    setSelectedId(draft.workspaceId);
    setNotice(undefined);
    setDiagnostics([]);
    setPublishRequest(request);
  }

  async function pullLatest() {
    setNotice(undefined);
    setDiagnostics([]);
    try {
      await pullWorkspaceRegistry();
      await Promise.all([statusQuery.refetch(), workspacesQuery.refetch()]);
      setNotice("Registry updated. Reload a workspace to review its latest revision.");
    } catch (error) {
      const safe = asWorkspaceApiError(error);
      setDiagnostics([safe ? `${safe.code}: ${safe.message}` : "git_unavailable: Registry pull could not be completed"]);
    }
  }

  async function validateSelectedWorkspace() {
    if (!record) return;
    setNotice(undefined);
    setDiagnostics([]);
    try {
      await validateWorkspace(record.workspace);
      setNotice("Workspace definition is valid.");
    } catch (error) {
      const safe = asWorkspaceApiError(error);
      setDiagnostics([safe ? `${safe.code}: ${safe.message}` : "workspace_invalid: Validation could not be completed"]);
    }
  }

  async function testSelectedWorkspace() {
    if (!record) return;
    setNotice(undefined);
    setDiagnostics([]);
    try {
      const result = await testWorkspace(record.workspace.workspace.id);
      setDiagnostics(result.diagnostics.map((diagnostic) => `${diagnostic.code}: ${diagnostic.message}`));
      if (result.diagnostics.length === 0) {
        setNotice(result.activatable ? "Installation test passed." : "Installation test completed.");
      }
    } catch (error) {
      const safe = asWorkspaceApiError(error);
      setDiagnostics([safe ? `${safe.code}: ${safe.message}` : "connector_unavailable: Installation test could not be completed"]);
    }
  }

  async function downloadBundle() {
    if (!record) return;
    setTransferring(true);
    setNotice(undefined);
    setDiagnostics([]);
    try {
      const bundle = await exportWorkspace(record.workspace.workspace.id);
      const url = URL.createObjectURL(bundle);
      const link = document.createElement("a");
      link.href = url;
      link.download = `${record.workspace.workspace.id}.zip`;
      link.click();
      URL.revokeObjectURL(url);
      setNotice("Workspace bundle downloaded.");
    } catch (error) {
      const safe = asWorkspaceApiError(error);
      setDiagnostics([safe ? `${safe.code}: ${safe.message}` : "workspace_invalid: Workspace bundle could not be exported"]);
    } finally {
      setTransferring(false);
    }
  }

  async function importBundle(file: File | undefined) {
    if (!file) return;
    setTransferring(true);
    setNotice(undefined);
    setDiagnostics([]);
    try {
      const result = await importWorkspace(file);
      const importedId = result.draft.workspace.workspace.id;
      const catalog = workspaces.length > 0 ? workspaces : ((await workspacesQuery.refetch()).data ?? []);
      const matchingSummary = catalog.find((workspace) => workspace.id === importedId && workspace.configurationState === "configuration_required");
      if (!matchingSummary) {
        setDiagnostics(["workspace_invalid: Imported bundle can only bootstrap a matching catalog slot"]);
        return;
      }
      const draft: WorkspaceBootstrapDraft = {
        workspaceId: importedId,
        baseCommit: statusQuery.data?.head ?? EMPTY_COMMIT,
        workspace: result.draft.workspace,
        updatedAt: new Date().toISOString(),
      };
      workspaceBootstrapDrafts.save(draft);
      setNotice("Imported bootstrap draft saved in this browser. Validate it before creating the descriptor.");
    } catch (error) {
      const safe = asWorkspaceApiError(error);
      setDiagnostics([safe ? `${safe.code}: ${safe.message}` : "workspace_invalid: Workspace bundle could not be imported"]);
    } finally {
      setTransferring(false);
    }
  }

  function published() {
    if (publishRequest) {
      workspaceBootstrapDrafts.discard(publishRequest.workspace.workspace.id);
      setSelectedId(publishRequest.workspace.workspace.id);
      setNotice(`To change this workspace, edit ${publishRequest.workspace.workspace.id}/workspace.yaml, commit/push, then Pull.`);
    } else {
      setNotice("Workspace created.");
    }
    setLocalDraft(undefined);
    setPublishRequest(undefined);
    setDiagnostics([]);
    void Promise.all([statusQuery.refetch(), workspacesQuery.refetch()]).then(() => detailQuery.refetch());
  }

  const titleReady = workspacesQuery.isSuccess || workspacesQuery.isError;

  return (
    <Dialog open={open} onOpenChange={(nextOpen) => { if (!nextOpen) onClose(); }}>
      <DialogContent showCloseButton={false} className="max-h-[min(90vh,54rem)] max-w-[min(94vw,74rem)] overflow-hidden p-0">
        <DialogHeader className="border-b border-border/70 px-5 pb-4 pt-5 pr-12">
          <DialogTitle>{titleReady ? "Workspace management" : ""}</DialogTitle>
          <DialogDescription>{titleReady ? "Draft bootstrap-only workspace definitions locally. Existing published descriptors stay read-only." : ""}</DialogDescription>
        </DialogHeader>
        <button type="button" aria-label="Close workspace management" onClick={onClose} className="absolute right-3 top-3 grid size-7 place-items-center rounded-md text-muted-foreground hover:bg-muted hover:text-foreground"><X className="size-4" /></button>
        <div className="grid max-h-[calc(min(90vh,54rem)-6.75rem)] min-h-[32rem] grid-cols-[14rem_minmax(0,1fr)] overflow-hidden">
          <nav aria-label="Workspaces" className="flex min-h-0 flex-col border-r border-border/70 bg-muted/30 p-3">
            <label className="mb-2 inline-flex h-7 cursor-pointer items-center justify-center gap-1 rounded-md border border-input px-3 text-[0.8rem] font-semibold text-foreground shadow-xs hover:bg-muted has-[:disabled]:cursor-not-allowed has-[:disabled]:opacity-50"><Upload className="size-3.5" />Import bundle<input aria-label="Import workspace bundle" type="file" accept="application/zip,.zip" className="sr-only" disabled={transferring} onChange={(event) => { const file = event.currentTarget.files?.[0]; event.currentTarget.value = ""; void importBundle(file); }} /></label>
            <Button size="sm" variant="outline" className="mb-3 w-full" disabled={transferring} onClick={() => { void pullLatest(); }}><GitPullRequest />Pull latest registry</Button>
            <div className="min-h-0 flex-1 overflow-y-auto">
              {workspacesQuery.isLoading ? <p className="p-2 text-xs text-muted-foreground">Loading workspaces…</p> : workspacesQuery.isError ? <QueryError name="Workspace list failed" message="Could not load workspaces." retryLabel="Retry workspace list" onRetry={() => { void workspacesQuery.refetch(); }} /> : workspaces.map((workspace) => (
                <button key={workspace.id} type="button" aria-label={workspace.displayName} aria-current={selectedId === workspace.id ? "page" : undefined} onClick={() => selectWorkspace(workspace.id)} className="mb-1 w-full rounded-md px-2.5 py-2 text-left text-sm hover:bg-muted aria-[current=page]:bg-primary/10 aria-[current=page]:font-semibold">
                  <span className="block truncate">{workspace.displayName}</span>
                  <span className="block truncate text-xs text-muted-foreground">{workspace.id}</span>
                </button>
              ))}
            </div>
          </nav>

          <div className="min-w-0 overflow-y-auto px-5 py-5">
            {notice && <p role="status" className="mb-4 flex items-center gap-2 rounded-md border border-border bg-muted/50 px-3 py-2 text-sm"><CheckCircle2 className="size-4 text-primary" />{notice}</p>}
            {diagnostics.length > 0 && <div data-testid="workspace-diagnostics" aria-live="polite" className="mb-4 grid gap-1 rounded-md border border-amber-500/30 bg-amber-500/10 px-3 py-2 text-sm">{diagnostics.map((diagnostic) => <p key={diagnostic} className="flex items-start gap-2"><AlertCircle className="mt-0.5 size-4 shrink-0 text-amber-700" />{diagnostic}</p>)}</div>}

            {!selectedSummary && !workspacesQuery.isLoading && !workspacesQuery.isError && <div className="grid min-h-64 place-items-center text-center"><div><h3 className="font-heading font-semibold">Select a workspace</h3><p className="mt-1 text-sm text-muted-foreground">Review an existing definition or bootstrap a configuration-required slot.</p></div></div>}

            {selectedSummary?.configurationState === "configuration_required" && activeBootstrapDraft && (
              <>
                <div className="mb-5 border-b border-border/70 pb-4">
                  <p className="thot-label">Bootstrap workspace</p>
                  <h2 className="font-heading text-lg font-semibold">{selectedSummary.displayName}</h2>
                  <p className="font-mono text-xs text-muted-foreground">{selectedSummary.id}</p>
                </div>
                <WorkspaceEditor
                  mode={{ kind: "bootstrap", catalog: selectedSummary, draft: activeBootstrapDraft }}
                  onSaveDraft={saveDraft}
                  onRequestCreate={publishRequest ? undefined : requestCreate}
                />
              </>
            )}

            {selectedSummary?.configurationState === "ready" && (
              detailQuery.isError ? <QueryError name="Workspace details failed" message="Could not load workspace details." retryLabel="Retry workspace details" onRetry={() => { void detailQuery.refetch(); }} /> : detailQuery.isLoading || !record ? <p className="text-sm text-muted-foreground">Loading workspace definition…</p> : (
                <>
                  <div className="mb-5 flex flex-wrap items-start justify-between gap-3 border-b border-border/70 pb-4">
                    <div>
                      <p className="thot-label">Workspace definition</p>
                      <h2 className="font-heading text-lg font-semibold">{record.workspace.workspace.name}</h2>
                      <p className="font-mono text-xs text-muted-foreground">{record.workspace.workspace.id}</p>
                    </div>
                    <div className="flex flex-wrap gap-2">
                      <Button size="sm" variant="outline" disabled={transferring} onClick={() => { void downloadBundle(); }}><Download />Export workspace bundle</Button>
                      <Button size="sm" variant="outline" onClick={() => { void validateSelectedWorkspace(); }}><ClipboardCheck />Validate workspace</Button>
                      <Button size="sm" variant="outline" onClick={() => { void testSelectedWorkspace(); }}><FlaskConical />Test on this installation</Button>
                    </div>
                  </div>
                  <WorkspaceEditor mode={{ kind: "read_only", catalog: selectedSummary, record: record as WorkspaceRecord }} />
                </>
              )
            )}
          </div>
        </div>
      </DialogContent>
      {publishRequest && <WorkspacePublishDialog open request={publishRequest} onOpenChange={(nextOpen) => { if (!nextOpen) setPublishRequest(undefined); }} onPublished={published} />}
    </Dialog>
  );
}