import {
  getSessionDistinctValues,
  getSessionList,
  getSessionReplayChunksFrom,
  SESSION_DISTINCT_FIELDS,
  sessionService,
} from '@openpanel/db';
import { zChartEventFilter } from '@openpanel/validation';
import { z } from 'zod';
import { createTRPCRouter, protectedProcedure } from '../trpc';

export function encodeCursor(cursor: {
  createdAt: string;
  id: string;
}): string {
  const json = JSON.stringify(cursor);
  return Buffer.from(json, 'utf8').toString('base64url'); // URL-safe
}

export function decodeCursor(
  encoded: string
): { createdAt: string; id: string } | null {
  try {
    const json = Buffer.from(encoded, 'base64url').toString('utf8');
    const obj = JSON.parse(json);
    if (typeof obj.createdAt === 'string' && typeof obj.id === 'string') {
      return obj;
    }
    return null;
  } catch {
    return null;
  }
}

export const sessionRouter = createTRPCRouter({
  list: protectedProcedure
    .input(
      z.object({
        projectId: z.string(),
        profileId: z.string().optional(),
        cursor: z.string().nullish(),
        filters: z.array(zChartEventFilter).default([]),
        startDate: z.date().optional(),
        endDate: z.date().optional(),
        search: z.string().optional(),
        take: z.number().default(50),
        minPageViews: z.number().nullish(),
        maxPageViews: z.number().nullish(),
        minEvents: z.number().nullish(),
        maxEvents: z.number().nullish(),
      })
    )
    .query(({ input }) => {
      return getSessionList({
        ...input,
        cursor: input.cursor ? new Date(input.cursor) : undefined,
      });
    }),

  distinctValues: protectedProcedure
    .input(
      z.object({
        projectId: z.string(),
        field: z.enum(SESSION_DISTINCT_FIELDS),
      })
    )
    .query(({ input }) => {
      return getSessionDistinctValues(input.projectId, input.field);
    }),

  byId: protectedProcedure
    .input(z.object({ sessionId: z.string(), projectId: z.string() }))
    .query(({ input: { sessionId, projectId } }) => {
      return sessionService.byId(sessionId, projectId);
    }),

  replayChunksFrom: protectedProcedure
    .input(
      z.object({
        sessionId: z.string(),
        projectId: z.string(),
        fromIndex: z.number().int().min(0).default(0),
      })
    )
    .query(({ input: { sessionId, projectId, fromIndex } }) => {
      return getSessionReplayChunksFrom(sessionId, projectId, fromIndex);
    }),
});