simstudioai--sim/apps/sim/tools/posthog/evaluate_flags.ts

import { getErrorMessage } from '@sim/utils/errors'
import { getPostHogIngestBaseUrl } from '@/tools/posthog/utils'
import type { ToolConfig } from '@/tools/types'

interface EvaluateFlagsParams {
  region: 'us' | 'eu'
  host?: string
  projectApiKey: string
  distinctId: string
  groups?: string
  personProperties?: string
  groupProperties?: string
}

interface FlagEvaluation {
  [key: string]: boolean | string
}

interface EvaluateFlagsResponse {
  feature_flags: FlagEvaluation
  feature_flag_payloads: Record<string, any>
  errors_while_computing_flags: boolean
}

export const evaluateFlagsTool: ToolConfig<EvaluateFlagsParams, EvaluateFlagsResponse> = {
  id: 'posthog_evaluate_flags',
  name: 'PostHog Evaluate Feature Flags',
  description:
    'Evaluate feature flags for a specific user or group. This is a public endpoint that uses the project API key.',
  version: '1.0.0',

  params: {
    region: {
      type: 'string',
      required: true,
      visibility: 'user-only',
      description: 'PostHog cloud region: us or eu',
    },
    host: {
      type: 'string',
      required: false,
      visibility: 'user-only',
      description:
        'Self-hosted PostHog instance host (e.g., "posthog.mycompany.com"). Overrides the region setting when provided.',
    },
    projectApiKey: {
      type: 'string',
      required: true,
      visibility: 'user-only',
      description: 'PostHog Project API Key (not personal API key)',
    },
    distinctId: {
      type: 'string',
      required: true,
      visibility: 'user-or-llm',
      description: 'The distinct ID of the user to evaluate flags for (e.g., "user123" or email)',
    },
    groups: {
      type: 'string',
      required: false,
      visibility: 'user-or-llm',
      description: 'Groups as JSON string (e.g., {"company": "company_id_in_your_db"})',
    },
    personProperties: {
      type: 'string',
      required: false,
      visibility: 'user-or-llm',
      description: 'Person properties as JSON string',
    },
    groupProperties: {
      type: 'string',
      required: false,
      visibility: 'user-or-llm',
      description: 'Group properties as JSON string',
    },
  },

  request: {
    url: (params) => {
      const baseUrl = getPostHogIngestBaseUrl(params.region, params.host)
      return `${baseUrl}/flags/?v=2`
    },
    method: 'POST',
    headers: () => ({
      'Content-Type': 'application/json',
    }),
    body: (params) => {
      const body: Record<string, any> = {
        api_key: params.projectApiKey,
        distinct_id: params.distinctId,
      }

      if (params.groups) {
        try {
          body.groups = JSON.parse(params.groups)
        } catch (error) {
          throw new Error(`Invalid groups JSON: ${getErrorMessage(error)}`)
        }
      }

      if (params.personProperties) {
        try {
          body.person_properties = JSON.parse(params.personProperties)
        } catch (error) {
          throw new Error(`Invalid personProperties JSON: ${getErrorMessage(error)}`)
        }
      }

      if (params.groupProperties) {
        try {
          body.group_properties = JSON.parse(params.groupProperties)
        } catch (error) {
          throw new Error(`Invalid groupProperties JSON: ${getErrorMessage(error)}`)
        }
      }

      return body
    },
  },

  transformResponse: async (response: Response) => {
    const data = await response.json()
    const flags: Record<
      string,
      { enabled?: boolean; variant?: string; metadata?: { payload?: string } }
    > = data.flags || {}

    const feature_flags: FlagEvaluation = {}
    const feature_flag_payloads: Record<string, any> = {}

    for (const [key, flag] of Object.entries(flags)) {
      feature_flags[key] = flag.variant ?? flag.enabled ?? false
      if (flag.metadata?.payload !== undefined) {
        try {
          feature_flag_payloads[key] = JSON.parse(flag.metadata.payload)
        } catch {
          feature_flag_payloads[key] = flag.metadata.payload
        }
      }
    }

    return {
      feature_flags,
      feature_flag_payloads,
      errors_while_computing_flags: data.errorsWhileComputingFlags || false,
    }
  },

  outputs: {
    feature_flags: {
      type: 'object',
      description:
        'Feature flag evaluations (key-value pairs where values are boolean or string variants)',
    },
    feature_flag_payloads: {
      type: 'object',
      description: 'Additional payloads attached to feature flags',
    },
    errors_while_computing_flags: {
      type: 'boolean',
      description: 'Whether there were errors while computing flags',
    },
  },
}