import { TRPCError } from "@trpc/server";
import { z } from "zod/v4";

import { decryptSecret } from "@homarr/common/server";
import {
  collectCustomWidgetRequestReferences,
  customWidgetAuthoringDefinitionSchema,
  customWidgetSecretsInputSchema,
  getCustomWidgetConfirmation,
  getCustomWidgetDefaultOptions,
  normalizeCustomWidgetAuthoringDefinition,
  validateCustomWidgetOptions,
} from "@homarr/custom-widgets/core";
import { eq } from "@homarr/db";
import { customWidgetDefinitions } from "@homarr/db/schema";

import { permissionRequiredProcedure } from "../../trpc";
import { parseCustomWidgetAuthoringInput } from "./authoring-validation";
import { createPreviewSession, getPreviewSession } from "./preview-sessions";
import { hasSameSecretBinding, requiredSecretKinds } from "./secret-policy";
import { parseStoredCustomWidgetDefinition } from "./stored-definition";

const previewCreateInputSchema = z.object({
  definition: customWidgetAuthoringDefinitionSchema,
  secrets: customWidgetSecretsInputSchema.default([]),
  definitionId: z.string().optional(),
  options: z.record(z.string(), z.unknown()).optional(),
});

const previewCreateProcedure = permissionRequiredProcedure
  .requiresPermission("admin")
  .meta({
    mcp: {
      enabled: true,
      description:
        "Create a short-lived preview for an unsaved custom widget after validation. Prefer templateLines for multiline JSX. The result lists every query that must be tested with customWidget_previewQuery before saving.",
    },
  })
  .input(previewCreateInputSchema)
  .mutation(async ({ ctx, input }) => {
    const definition = parseCustomWidgetAuthoringInput(() =>
      normalizeCustomWidgetAuthoringDefinition(input.definition),
    );
    const options = input.options ?? getCustomWidgetDefaultOptions(definition.options);
    const optionIssues = validateCustomWidgetOptions(definition.options, options);
    if (optionIssues.length > 0) {
      const issue = optionIssues[0];
      throw new TRPCError({
        code: "BAD_REQUEST",
        message: issue ? `${issue.path}: ${issue.message}` : "Preview options are invalid",
      });
    }

    const secrets = [...input.secrets];
    if (input.definitionId) {
      const existing = await ctx.db.query.customWidgetDefinitions.findFirst({
        where: eq(customWidgetDefinitions.id, input.definitionId),
        with: { secrets: true },
      });
      if (!existing) throw new TRPCError({ code: "NOT_FOUND", message: "Custom widget definition not found" });
      const existingDefinition = parseStoredCustomWidgetDefinition(existing);
      for (const [sourceId, existingSource] of Object.entries(existingDefinition.sources)) {
        const submittedSource = definition.sources[sourceId];
        const hasStoredSecrets = existing.secrets.some((secret) => secret.sourceId === sourceId);
        if (!submittedSource || !hasStoredSecrets || hasSameSecretBinding(existingSource, submittedSource)) continue;

        const authType = typeof submittedSource.auth === "string" ? submittedSource.auth : submittedSource.auth.type;
        const missingReplacement = requiredSecretKinds(authType).some(
          (kind) => !secrets.some((secret) => secret.sourceId === sourceId && secret.kind === kind),
        );
        if (missingReplacement) {
          throw new TRPCError({
            code: "BAD_REQUEST",
            message: "Source security settings changed; re-enter its credentials to preview this definition",
          });
        }
      }
      for (const secret of existing.secrets) {
        const existingSource = existingDefinition.sources[secret.sourceId];
        const submittedSource = definition.sources[secret.sourceId];
        if (
          existingSource &&
          submittedSource &&
          hasSameSecretBinding(existingSource, submittedSource) &&
          !secrets.some((candidate) => candidate.sourceId === secret.sourceId && candidate.kind === secret.kind)
        ) {
          secrets.push({ sourceId: secret.sourceId, kind: secret.kind, value: decryptSecret(secret.encryptedValue) });
        }
      }
    }

    const invalid = secrets.find((secret) => {
      const source = definition.sources[secret.sourceId];
      const authType = typeof source?.auth === "string" ? source.auth : source?.auth.type;
      const kinds =
        authType === "basic"
          ? ["username", "password"]
          : source && authType && ["bearer", "apiKeyHeader", "apiKeyQuery"].includes(authType)
            ? ["apiKey"]
            : [];
      return !source || !kinds.includes(secret.kind);
    });
    if (invalid) {
      throw new TRPCError({ code: "BAD_REQUEST", message: `Unknown secret source '${invalid.sourceId}'` });
    }

    const previewSession = await createPreviewSession({
      userId: ctx.session.user.id,
      sources: definition.sources,
      requests: definition.requests,
      name: definition.name,
      template: definition.template,
      optionDefinitions: definition.options,
      options,
      secrets,
      definitionId: input.definitionId,
    });
    const previewPath = `/manage/custom-widgets/preview/${previewSession.id}`;
    return {
      success: true as const,
      previewSession,
      previewPath,
      previewUrl: new URL(previewPath, ctx.baseUrl ?? "http://localhost").toString(),
      queries: Object.entries(definition.requests).flatMap(([requestId, request]) => {
        if (request.kind !== "query") return [];
        return [
          {
            requestId,
            trigger: request.trigger,
            parameterNames: [...collectCustomWidgetRequestReferences(request).params],
            nextStep: `Call customWidget_previewQuery with sessionId '${previewSession.id}' and requestId '${requestId}'.`,
          },
        ];
      }),
    };
  });

export const previewBaseProcedures = {
  previewCreate: previewCreateProcedure,
  previewGet: permissionRequiredProcedure
    .requiresPermission("admin")
    .input(z.object({ sessionId: z.string() }))
    .query(async ({ ctx, input }) => {
      const session = await getPreviewSession(input.sessionId, ctx.session.user.id);
      return {
        id: session.id,
        name: session.name,
        expiresAt: session.expiresAt,
        template: session.template,
        optionDefinitions: session.optionDefinitions,
        options: session.options,
        requests: Object.entries(session.requests).map(([id, request]) => ({
          id,
          kind: request.kind,
          method: request.method,
          minimumBoardPermission: request.permission,
          trigger: request.trigger,
          confirmation: getCustomWidgetConfirmation(request),
          invalidates: request.invalidates,
        })),
        liveActions: session.liveActions,
      };
    }),
};