import { useMemo, useState } from "react";
import { useQuery, useQueryClient } from "@tanstack/react-query";
import {
  AlertCircle,
  CheckCircle2,
  ClipboardCheck,
  FlaskConical,
  GitPullRequest,
  KeyRound,
  Trash2,
  X,
} from "lucide-react";

import {
  asWorkspaceApiError,
  forgetWorkspaceSecret,
  getWorkspace,
  getWorkspaceRegistryStatus,
  getWorkspaceRuntimeConfiguration,
  listWorkspaces,
  pullWorkspaceRegistry,
  saveWorkspaceSecrets,
  testWorkspace,
  validateWorkspace,
  type WorkspaceRuntimeConfiguration,
} from "../api/workspaces";
import { Button } from "../components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogHeader,
  DialogTitle,
} from "../components/ui/dialog";

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 publicError(error: unknown, fallback: string): string {
  const safe = asWorkspaceApiError(error);
  return safe ? `${safe.code}: ${safe.message}` : fallback;
}

function stateLabel(state: "ready" | "configuration_required"): string {
  return state === "ready" ? "Ready" : "Runtime configuration required";
}

export function WorkspaceManager({ open, onClose }: { open: boolean; onClose: () => void }) {
  const queryClient = useQueryClient();
  const [selectedId, setSelectedId] = useState<string>();
  const [secretValues, setSecretValues] = useState<Record<string, string>>({});
  const [notice, setNotice] = useState<string>();
  const [diagnostics, setDiagnostics] = useState<string[]>([]);
  const [busyAction, setBusyAction] = useState<string>();

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

  const clearMessages = () => {
    setNotice(undefined);
    setDiagnostics([]);
  };

  const close = () => {
    setSecretValues({});
    clearMessages();
    onClose();
  };

  const selectWorkspace = (id: string) => {
    setSelectedId(id);
    setSecretValues({});
    clearMessages();
  };

  async function updateRepository() {
    setBusyAction("repository");
    clearMessages();
    try {
      await pullWorkspaceRegistry();
      await Promise.all([
        statusQuery.refetch(),
        workspacesQuery.refetch(),
        selectedId ? detailQuery.refetch() : Promise.resolve(),
        selectedId ? runtimeQuery.refetch() : Promise.resolve(),
      ]);
      setNotice("Workspace repository updated and validated.");
    } catch (error) {
      setDiagnostics([publicError(error, "git_unavailable: Workspace repository could not be updated")]);
    } finally {
      setBusyAction(undefined);
    }
  }

  async function validateSource() {
    if (!detailQuery.data) return;
    setBusyAction("validate");
    clearMessages();
    try {
      await validateWorkspace(detailQuery.data.workspace);
      setNotice("Workspace source is valid.");
    } catch (error) {
      setDiagnostics([publicError(error, "workspace_invalid: Workspace validation could not be completed")]);
    } finally {
      setBusyAction(undefined);
    }
  }

  async function testConnections() {
    if (!selectedId) return;
    setBusyAction("test");
    clearMessages();
    try {
      const result = await testWorkspace(selectedId);
      setDiagnostics(result.diagnostics.map(({ code, message }) => `${code}: ${message}`));
      if (result.diagnostics.length === 0) {
        setNotice(result.activatable
          ? "Workspace connections are valid."
          : "Workspace connection test completed.");
      }
    } catch (error) {
      setDiagnostics([publicError(error, "connector_unavailable: Workspace connections could not be tested")]);
    } finally {
      setBusyAction(undefined);
    }
  }

  async function saveSecrets() {
    if (!selectedId) return;
    const values = Object.fromEntries(
      Object.entries(secretValues).filter(([, value]) => value.length > 0),
    );
    if (Object.keys(values).length === 0) return;
    setBusyAction("save-secrets");
    clearMessages();
    try {
      const configuration = await saveWorkspaceSecrets(selectedId, values);
      queryClient.setQueryData(
        ["workspace-runtime-configuration", selectedId],
        configuration,
      );
      setSecretValues({});
      await workspacesQuery.refetch();
      setNotice("Runtime secrets saved. Stored values remain hidden.");
    } catch (error) {
      setDiagnostics([publicError(error, "workspace_invalid: Runtime secrets could not be saved")]);
    } finally {
      setBusyAction(undefined);
    }
  }

  async function forgetSecret(requirementId: string) {
    if (!selectedId) return;
    setBusyAction(`forget:${requirementId}`);
    clearMessages();
    try {
      const configuration = await forgetWorkspaceSecret(selectedId, requirementId);
      queryClient.setQueryData(
        ["workspace-runtime-configuration", selectedId],
        configuration,
      );
      setSecretValues((current) => ({ ...current, [requirementId]: "" }));
      await workspacesQuery.refetch();
      setNotice("Stored secret forgotten.");
    } catch (error) {
      setDiagnostics([publicError(error, "workspace_invalid: Stored secret could not be forgotten")]);
    } finally {
      setBusyAction(undefined);
    }
  }

  const repository = statusQuery.data?.repository;
  const repositoryLabel = repository
    ? `${repository.host}/${repository.repository}`
    : "the repository configured for this ThothII installation";
  const runtime = runtimeQuery.data;
  const hasEnteredSecrets = Object.values(secretValues).some((value) => value.length > 0);

  return (
    <Dialog open={open} onOpenChange={(nextOpen) => { if (!nextOpen) close(); }}>
      <DialogContent
        showCloseButton={false}
        className="h-[70vh] w-[94vw] max-h-[90vh] max-w-[94vw] grid-rows-[auto_minmax(0,1fr)] gap-0 overflow-hidden p-0 sm:w-[70vw] sm:max-w-[94vw]"
      >
        <DialogHeader className="border-b border-border/70 px-6 pb-4 pt-5 pr-12">
          <DialogTitle>Workspace management</DialogTitle>
          <DialogDescription>
            Read, validate, and complete the runtime configuration of workspaces supplied by the installation repository.
          </DialogDescription>
        </DialogHeader>
        <button type="button" aria-label="Close workspace management" onClick={close} 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 min-h-0 grid-cols-[15rem_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">
            <p className="mb-2 px-2 text-xs font-semibold uppercase tracking-wide text-muted-foreground">Available workspaces</p>
            <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>
                  <span className="mt-1 block text-[0.7rem] text-muted-foreground">{stateLabel(workspace.configurationState)}</span>
                </button>
              ))}
            </div>
          </nav>

          <main className="min-w-0 overflow-y-auto px-6 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 ? (
              <section data-testid="workspace-overview" className="mx-auto max-w-3xl space-y-5">
                <div>
                  <p className="thot-label">Level 1 · Repository</p>
                  <h2 className="font-heading text-xl font-semibold">How workspaces reach ThothII</h2>
                </div>
                <ol className="grid list-decimal gap-3 pl-5 text-sm leading-6 text-muted-foreground">
                  <li><span className="font-medium text-foreground">Create a local workspace</span> in its own source directory. It must contain <code>workspace.yaml</code> and every required subdirectory, including any versioned Evidence files.</li>
                  <li>Publish that source by committing and pushing it to a repository hosted by a Git server such as GitHub, GitLab, or Gitea.</li>
                  <li>The repository address, branch, and read-only Git credentials are configured during ThothII installation. This installation reads <span className="font-medium text-foreground">{repositoryLabel}</span> on branch <span className="font-mono text-foreground">{statusQuery.data?.branch ?? "main"}</span>.</li>
                  <li>ThothII fetches the configured branch into its managed read-only checkout, validates the complete candidate revision, and activates it only when validation succeeds. It never edits, commits, pushes, or publishes workspace source.</li>
                </ol>
                <div className="rounded-lg border border-border bg-muted/30 p-4">
                  <div className="flex flex-wrap items-start justify-between gap-4">
                    <div className="max-w-2xl">
                      <h3 className="font-heading font-semibold">Update workspace repository</h3>
                      <p className="mt-1 text-sm leading-6 text-muted-foreground">Fetches the configured branch directly into the managed read-only checkout and validates it. No workspace selection is required. If candidate validation fails, the current active revision remains unchanged.</p>
                    </div>
                    <Button disabled={busyAction === "repository"} onClick={() => { void updateRepository(); }}>
                      <GitPullRequest />Update workspace repository
                    </Button>
                  </div>
                </div>
                <p className="text-sm text-muted-foreground">Select a workspace from the left only for workspace-specific validation, runtime credentials, and connection tests.</p>
              </section>
            ) : (
              <section className="mx-auto max-w-4xl space-y-5">
                <div className="border-b border-border/70 pb-4">
                  <p className="thot-label">Level 2 · Selected workspace</p>
                  <h2 className="font-heading text-xl font-semibold">{selectedSummary.displayName}</h2>
                  <p className="font-mono text-xs text-muted-foreground">{selectedSummary.id}</p>
                </div>

                {(detailQuery.isLoading || runtimeQuery.isLoading) && <p className="text-sm text-muted-foreground">Loading workspace configuration…</p>}
                {(detailQuery.isError || runtimeQuery.isError) && (
                  <QueryError name="Workspace configuration failed" message="Could not load this workspace configuration." retryLabel="Retry workspace configuration" onRetry={() => { void Promise.all([detailQuery.refetch(), runtimeQuery.refetch()]); }} />
                )}

                {detailQuery.data && runtime && (
                  <>
                    <div>
                      <h3 className="font-heading text-lg font-semibold">Workspace-specific actions</h3>
                      <p className="mt-1 text-sm text-muted-foreground">The actions below apply only to <span className="font-medium text-foreground">{selectedSummary.displayName}</span>. ThothII reads this revision without modifying or publishing it.</p>
                    </div>

                    <dl className="grid gap-3 rounded-lg border border-border bg-muted/20 p-4 text-sm sm:grid-cols-2">
                      <div><dt className="text-xs text-muted-foreground">Source file</dt><dd className="font-mono">{selectedSummary.file}</dd></div>
                      <div><dt className="text-xs text-muted-foreground">Active revision</dt><dd className="truncate font-mono">{detailQuery.data.revision.commit}</dd></div>
                      <div><dt className="text-xs text-muted-foreground">Data warehouse</dt><dd>{detailQuery.data.workspace.dwh.engine} · {detailQuery.data.workspace.dwh.database}/{detailQuery.data.workspace.dwh.schema}</dd></div>
                      <div><dt className="text-xs text-muted-foreground">Runtime status</dt><dd>{stateLabel(runtime.configurationState)}</dd></div>
                    </dl>

                    <div className="grid gap-3 lg:grid-cols-2">
                      <div className="rounded-lg border border-border p-4">
                        <h4 className="font-heading font-semibold">Validate workspace source</h4>
                        <p className="mt-1 min-h-12 text-sm leading-5 text-muted-foreground">Checks workspace.yaml and the required workspace directories against the supported workspace schema. No source file is changed.</p>
                        <Button className="mt-3" size="sm" variant="outline" disabled={busyAction === "validate"} onClick={() => { void validateSource(); }}>
                          <ClipboardCheck />Validate workspace source
                        </Button>
                      </div>
                      <div className="rounded-lg border border-border p-4">
                        <h4 className="font-heading font-semibold">Test workspace connections</h4>
                        <p className="mt-1 min-h-12 text-sm leading-5 text-muted-foreground">Uses temporary decrypted credentials to verify the configured data warehouse and Evidence source. Temporary files are deleted after the test.</p>
                        <Button className="mt-3" size="sm" variant="outline" disabled={busyAction === "test"} onClick={() => { void testConnections(); }}>
                          <FlaskConical />Test workspace connections
                        </Button>
                      </div>
                    </div>

                    <div className="rounded-lg border border-border p-4">
                      <div className="mb-4 flex items-start gap-3">
                        <KeyRound className="mt-0.5 size-5 text-primary" />
                        <div>
                          <h3 className="font-heading font-semibold">Runtime secrets</h3>
                          <p className="mt-1 text-sm leading-5 text-muted-foreground">Enter only new or replacement values. Stored values are never displayed. Saving replaces the selected secret and clears the form field.</p>
                        </div>
                      </div>
                      {runtime.requirements.length === 0 ? (
                        <p className="text-sm text-muted-foreground">This workspace does not require user-provided runtime secrets for its selected connectors.</p>
                      ) : (
                        <div className="grid gap-4">
                          {runtime.requirements.map((requirement) => (
                            <div key={requirement.id} className="grid gap-2 rounded-md bg-muted/30 p-3">
                              <div className="flex flex-wrap items-center justify-between gap-2">
                                <label htmlFor={`workspace-secret-${requirement.id}`} className="font-medium">{requirement.label}</label>
                                <span className={requirement.configured ? "text-xs font-medium text-emerald-700" : "text-xs font-medium text-amber-700"}>
                                  {requirement.configured ? "Configured" : "Not configured"}
                                </span>
                              </div>
                              <p className="text-xs text-muted-foreground">{requirement.description}{requirement.required ? " Required for this workspace." : " Optional."}</p>
                              {requirement.input === "textarea" ? (
                                <textarea
                                  id={`workspace-secret-${requirement.id}`}
                                  value={secretValues[requirement.id] ?? ""}
                                  placeholder="Enter a new or replacement value"
                                  autoComplete="off"
                                  rows={4}
                                  onChange={(event) => setSecretValues((current) => ({ ...current, [requirement.id]: event.target.value }))}
                                  className="w-full rounded-md border border-input bg-background px-3 py-2 font-mono text-sm outline-none focus-visible:ring-2 focus-visible:ring-ring"
                                />
                              ) : (
                                <input
                                  id={`workspace-secret-${requirement.id}`}
                                  type="password"
                                  value={secretValues[requirement.id] ?? ""}
                                  placeholder="Enter a new or replacement value"
                                  autoComplete="new-password"
                                  onChange={(event) => setSecretValues((current) => ({ ...current, [requirement.id]: event.target.value }))}
                                  className="h-9 w-full rounded-md border border-input bg-background px-3 text-sm outline-none focus-visible:ring-2 focus-visible:ring-ring"
                                />
                              )}
                              {requirement.configured && (
                                <div>
                                  <Button
                                    size="sm"
                                    variant="ghost"
                                    disabled={busyAction === `forget:${requirement.id}`}
                                    aria-label={`Forget stored ${requirement.label}`}
                                    onClick={() => { void forgetSecret(requirement.id); }}
                                  >
                                    <Trash2 />Forget stored value
                                  </Button>
                                </div>
                              )}
                            </div>
                          ))}
                          <div>
                            <Button disabled={!hasEnteredSecrets || busyAction === "save-secrets"} onClick={() => { void saveSecrets(); }}>
                              <KeyRound />Save entered secrets
                            </Button>
                          </div>
                        </div>
                      )}
                    </div>
                  </>
                )}
              </section>
            )}
          </main>
        </div>
      </DialogContent>
    </Dialog>
  );
}