import { Save } from "lucide-react";
import { useCallback, useEffect, useMemo, useState } from "react";
import {
  Button,
  Dialog,
  DialogForm,
  DialogSection,
  DismissibleAlert,
  FormField,
  FormGrid,
  LoadingIndicator,
  StatusBadge,
  ToggleSwitch,
  type PlatformRouteContext
} from "@govoplan/core-webui";
import {
  listFormIntakeDefinitions,
  listFormStatusAccessPolicies,
  saveFormStatusAccessPolicy,
  type FormDefinition,
  type FormStatusAccessMode,
  type FormStatusAccessPolicy
} from "../../api/formsRuntime";


type StatusAccessPoliciesDialogProps = {
  open: boolean;
  settings: PlatformRouteContext["settings"];
  onClose: () => void;
};

export default function StatusAccessPoliciesDialog({
  open,
  settings,
  onClose
}: StatusAccessPoliciesDialogProps) {
  const [definitions, setDefinitions] = useState<FormDefinition[]>([]);
  const [policies, setPolicies] = useState<FormStatusAccessPolicy[]>([]);
  const [definitionKey, setDefinitionKey] = useState("");
  const [mode, setMode] = useState<FormStatusAccessMode>("authenticated");
  const [emailFieldKey, setEmailFieldKey] = useState("");
  const [tokenMinutes, setTokenMinutes] = useState(60);
  const [requestLimit, setRequestLimit] = useState(5);
  const [enabled, setEnabled] = useState(true);
  const [loading, setLoading] = useState(false);
  const [busyKey, setBusyKey] = useState("");
  const [error, setError] = useState("");
  const [notice, setNotice] = useState("");

  const load = useCallback(async (signal?: AbortSignal) => {
    setLoading(true);
    setError("");
    try {
      const [definitionResult, policyResult] = await Promise.all([
        listFormIntakeDefinitions(settings, signal),
        listFormStatusAccessPolicies(settings, signal)
      ]);
      setDefinitions(definitionResult.definitions);
      setPolicies(policyResult.policies);
      setDefinitionKey((current) => current || referenceKey(definitionResult.definitions[0]));
    } finally {
      setLoading(false);
    }
  }, [settings]);

  useEffect(() => {
    if (!open) return undefined;
    const controller = new AbortController();
    void load(controller.signal).catch((reason) => {
      if ((reason as Error).name !== "AbortError") {
        setError(reason instanceof Error ? reason.message : "Status access policies could not be loaded.");
      }
    });
    return () => controller.abort();
  }, [load, open]);

  const definition = useMemo(
    () => definitions.find((item) => referenceKey(item) === definitionKey),
    [definitionKey, definitions]
  );
  const policy = useMemo(
    () => policies.find((item) => referenceKey(item) === definitionKey),
    [definitionKey, policies]
  );

  useEffect(() => {
    if (!definitionKey) return;
    if (policy) {
      setMode(policy.mode);
      setEmailFieldKey(policy.email_field_key ?? "");
      setTokenMinutes(Math.max(5, Math.round(policy.token_ttl_seconds / 60)));
      setRequestLimit(policy.request_limit_per_hour);
      setEnabled(policy.enabled);
      return;
    }
    setMode("authenticated");
    setEmailFieldKey("");
    setTokenMinutes(60);
    setRequestLimit(5);
    setEnabled(true);
  }, [definitionKey, policy]);

  async function save() {
    if (!definition || (mode === "email_link" && !emailFieldKey)) return;
    setBusyKey(definitionKey);
    setError("");
    setNotice("");
    try {
      await saveFormStatusAccessPolicy(settings, {
        definitionRef: definition.reference,
        mode,
        enabled,
        emailFieldKey,
        tokenTtlSeconds: tokenMinutes * 60,
        requestLimitPerHour: requestLimit,
        expectedRevision: policy?.revision
      });
      await load();
      setNotice("The applicant status access policy was saved.");
    } catch (reason) {
      setError(reason instanceof Error ? reason.message : "The status access policy could not be saved.");
    } finally {
      setBusyKey("");
    }
  }

  async function toggle(item: FormStatusAccessPolicy, nextEnabled: boolean) {
    const exactDefinition = definitions.find((candidate) => referenceKey(candidate) === referenceKey(item));
    if (!exactDefinition) return;
    setBusyKey(item.policy_id);
    setError("");
    setNotice("");
    try {
      await saveFormStatusAccessPolicy(settings, {
        definitionRef: exactDefinition.reference,
        mode: item.mode,
        enabled: nextEnabled,
        emailFieldKey: item.email_field_key ?? undefined,
        tokenTtlSeconds: item.token_ttl_seconds,
        requestLimitPerHour: item.request_limit_per_hour,
        expectedRevision: item.revision
      });
      await load();
      setNotice(nextEnabled
        ? "Applicant status access was enabled for future submissions and existing grants."
        : "Applicant status access and all existing grants for this exact Form revision were suspended."
      );
    } catch (reason) {
      setError(reason instanceof Error ? reason.message : "The status access policy could not be changed.");
    } finally {
      setBusyKey("");
    }
  }

  return (
    <Dialog
      open={open}
      title="Applicant status access"
      description="Choose the access and disclosure profile independently for each exact published Form revision."
      size="large"
      closeDisabled={Boolean(busyKey)}
      onClose={onClose}
      helpContextId="forms_runtime.status-policy"
      helpTopicId="forms_runtime.submissions"
      footer={<Button onClick={onClose} disabled={Boolean(busyKey)}>Close</Button>}>
      {error && <DismissibleAlert tone="danger" resetKey={error}>{error}</DismissibleAlert>}
      {notice && <DismissibleAlert tone="success" resetKey={notice}>{notice}</DismissibleAlert>}
      {loading && <LoadingIndicator label="Loading applicant status policies" />}
      {!loading && definitions.length === 0 &&
        <DismissibleAlert tone="info">Publish a Form revision before configuring applicant status.</DismissibleAlert>
      }
      {!loading && definitions.length > 0 &&
        <DialogForm onSubmit={(event) => { event.preventDefault(); void save(); }}>
          <DialogSection title={policy ? "Edit policy" : "Add policy"}>
            <FormGrid columns={2} gap="small" collapseAt="workspace">
              <FormField label="Published Form">
                <select value={definitionKey} onChange={(event) => setDefinitionKey(event.target.value)} disabled={Boolean(busyKey)}>
                  {definitions.map((item) =>
                    <option key={referenceKey(item)} value={referenceKey(item)}>
                      {item.title} · revision {item.reference.version}
                    </option>
                  )}
                </select>
              </FormField>
              <FormField label="Access profile">
                <select value={mode} onChange={(event) => setMode(event.target.value as FormStatusAccessMode)} disabled={Boolean(busyKey)}>
                  <option value="authenticated">Authenticated applicant only</option>
                  <option value="email_link">Short-lived link to linked email</option>
                  <option value="permanent_link">Permanent public bearer link</option>
                </select>
              </FormField>
              {mode === "email_link" &&
                <FormField label="Linked email field" help="The final submitted value is compared without disclosing whether a request matched.">
                  <select value={emailFieldKey} onChange={(event) => setEmailFieldKey(event.target.value)} disabled={Boolean(busyKey)} required>
                    <option value="">Select a field</option>
                    {definition?.fields.filter((field) => field.value_type === "email").map((field) =>
                      <option key={field.key} value={field.key}>{field.label} ({field.key})</option>
                    )}
                  </select>
                </FormField>
              }
              {mode === "email_link" &&
                <FormField label="Link validity (minutes)">
                  <input type="number" min={5} max={10_080} value={tokenMinutes} onChange={(event) => setTokenMinutes(Number(event.target.value))} disabled={Boolean(busyKey)} />
                </FormField>
              }
              {mode === "email_link" &&
                <FormField label="Requests per hour">
                  <input type="number" min={1} max={60} value={requestLimit} onChange={(event) => setRequestLimit(Number(event.target.value))} disabled={Boolean(busyKey)} />
                </FormField>
              }
              <FormField label="Policy state">
                <ToggleSwitch label="Applicant status enabled" checked={enabled} onChange={setEnabled} disabled={Boolean(busyKey)} />
              </FormField>
            </FormGrid>
            <AccessConsequence mode={mode} />
            <div className="form-status-policy-save">
              <Button
                variant="primary"
                type="submit"
                disabled={Boolean(busyKey) || !definition || (mode === "email_link" && !emailFieldKey)}>
                <Save size={16} aria-hidden="true" />
                Save policy
              </Button>
            </div>
          </DialogSection>
          <DialogSection title="Configured policies" variant="inset">
            {policies.length === 0 && <p className="form-intake-empty">No applicant status policy has been configured.</p>}
            <div className="form-status-policy-list">
              {policies.map((item) =>
                <div className="form-status-policy-row" key={item.policy_id}>
                  <span>
                    <strong>{policyTitle(item)}</strong>
                    <small>Revision {item.definition_ref.version} · {modeLabel(item.mode)}</small>
                  </span>
                  <StatusBadge status={item.enabled ? "active" : "inactive"} label={item.enabled ? "Enabled" : "Suspended"} />
                  <ToggleSwitch
                    label="Policy enabled"
                    checked={item.enabled}
                    disabled={Boolean(busyKey)}
                    onChange={(value) => void toggle(item, value)}
                  />
                </div>
              )}
            </div>
          </DialogSection>
        </DialogForm>
      }
    </Dialog>
  );
}

function AccessConsequence({ mode }: { mode: FormStatusAccessMode }) {
  if (mode === "authenticated") {
    return <DismissibleAlert tone="info">Only the bound applicant account can view status. Assisted intake needs an explicit <code>account:</code> party reference for this profile.</DismissibleAlert>;
  }
  if (mode === "email_link") {
    return <DismissibleAlert tone="warning">A matching identifier and email request creates a new expiring secret and revokes the previous one. Notifications and Mail must be configured for delivery.</DismissibleAlert>;
  }
  return <DismissibleAlert tone="warning">The link does not expire or require sign-in. Anyone holding it can see the bounded status timeline until the policy is suspended.</DismissibleAlert>;
}

function referenceKey(value?: FormDefinition | FormStatusAccessPolicy): string {
  if (!value) return "";
  const reference = "definition_ref" in value ? value.definition_ref : value.reference;
  return `${reference.object_id}:${reference.version ?? ""}`;
}

function policyTitle(policy: FormStatusAccessPolicy): string {
  const title = policy.metadata.definition_title;
  return typeof title === "string" && title.trim()
    ? title
    : policy.definition_ref.label ?? policy.definition_ref.object_id;
}

function modeLabel(mode: FormStatusAccessMode): string {
  if (mode === "authenticated") return "Authenticated applicant";
  if (mode === "email_link") return "Short-lived email link";
  return "Permanent public link";
}