# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

openapi: "3.1.2"

info:
  title: Apache Nutch REST API
  description: >-
    REST API for managing Apache Nutch crawl jobs, configurations, seed lists,
    database queries, and data readers.
  version: "1.0.0"
  license:
    name: Apache 2.0
    identifier: Apache-2.0
  contact:
    name: Apache Nutch
    url: https://nutch.apache.org

servers:
  - url: "{protocol}://localhost:{port}"
    description: Nutch REST server
    variables:
      protocol:
        default: http
        enum:
          - http
          - https
        description: The protocol used to access the Nutch server.
      port:
        default: "8081"
        description: >-
          The port the Nutch server listens on. Configurable via the --port
          command-line argument.

security:
  - basicAuth: []

tags:
  - name: Admin
    description: Server administration operations
  - name: Configuration
    description: Manage Nutch configurations
  - name: Job
    description: Manage crawl jobs
  - name: Database
    description: Query the CrawlDB and FetchDB
  - name: Seed
    description: Manage seed URL lists
  - name: Reader
    description: Read sequence files and webgraph data
  - name: Services
    description: Auxiliary service operations such as CommonCrawl data dumps

paths:
  # ---------------------------------------------------------------------------
  # Admin
  # ---------------------------------------------------------------------------
  /admin/:
    get:
      tags:
        - Admin
      summary: Get server status
      description: >-
        Returns the current status of the Nutch server including start date,
        known configurations, all jobs, and currently running jobs.
      operationId: getServerStatus
      responses:
        "200":
          description: Server status retrieved successfully.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/NutchServerInfo"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /admin/stop:
    get:
      tags:
        - Admin
      summary: Stop the Nutch server
      description: >-
        Initiates a graceful shutdown of the Nutch server. If jobs are still
        running and force is not set, the server will refuse to stop.
      operationId: stopServer
      parameters:
        - name: force
          in: query
          required: false
          description: >-
            If true, kills any running jobs before stopping the server.
          schema:
            type: boolean
            default: false
      responses:
        "200":
          description: Shutdown status message.
          content:
            application/json:
              schema:
                type: string
              examples:
                stopping:
                  value: "Stopping in server on port 8081"
                busy:
                  value: "Jobs still running -- Cannot stop server now"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Configuration
  # ---------------------------------------------------------------------------
  /config/:
    get:
      tags:
        - Configuration
      summary: List all configuration IDs
      description: Returns the set of all known configuration identifiers.
      operationId: getConfigs
      responses:
        "200":
          description: A JSON array of configuration ID strings.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: string
                uniqueItems: true
              example:
                - default
                - my-custom-config
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /config/{configId}:
    get:
      tags:
        - Configuration
      summary: Get configuration properties
      description: Returns all key-value properties for the specified configuration.
      operationId: getConfig
      parameters:
        - $ref: "#/components/parameters/configId"
      responses:
        "200":
          description: A JSON object of configuration property key-value pairs.
          content:
            application/json:
              schema:
                type: object
                additionalProperties:
                  type: string
              example:
                http.agent.name: "NutchBot"
                http.robots.agents: "NutchBot,*"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"
    delete:
      tags:
        - Configuration
      summary: Delete a configuration
      description: >-
        Removes the specified configuration from the list of known
        configurations.
      operationId: deleteConfig
      parameters:
        - $ref: "#/components/parameters/configId"
      responses:
        "204":
          description: Configuration deleted successfully.
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /config/{configId}/{propertyId}:
    get:
      tags:
        - Configuration
      summary: Get a single configuration property
      description: >-
        Returns the value of a specific property within the given
        configuration.
      operationId: getProperty
      parameters:
        - $ref: "#/components/parameters/configId"
        - $ref: "#/components/parameters/propertyId"
      responses:
        "200":
          description: The property value as plain text.
          content:
            text/plain:
              schema:
                type: string
              example: "NutchBot"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"
    put:
      tags:
        - Configuration
      summary: Update a configuration property
      description: >-
        Adds or updates the value of a property in the specified
        configuration.
      operationId: updateProperty
      parameters:
        - $ref: "#/components/parameters/configId"
        - $ref: "#/components/parameters/propertyId"
      requestBody:
        required: true
        description: The new property value as plain text.
        content:
          text/plain:
            schema:
              type: string
            example: "MyNewBot"
      responses:
        "200":
          description: Property updated successfully.
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /config/create:
    post:
      tags:
        - Configuration
      summary: Create a new configuration
      description: >-
        Creates a new Nutch configuration with the specified parameters.
        Returns the configuration ID on success.
      operationId: createConfig
      requestBody:
        required: true
        description: The configuration to create.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/NutchConfig"
      responses:
        "200":
          description: Configuration created. Returns the configuration ID.
          content:
            text/plain:
              schema:
                type: string
              example: "my-custom-config"
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Job
  # ---------------------------------------------------------------------------
  /job/:
    get:
      tags:
        - Job
      summary: List all jobs
      description: >-
        Returns job history for all jobs or filtered by crawl ID, regardless
        of job state.
      operationId: getJobs
      parameters:
        - name: crawlId
          in: query
          required: false
          description: Optional crawl ID to filter jobs by.
          schema:
            type: string
      responses:
        "200":
          description: A JSON array of job information objects.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/JobInfo"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /job/{id}:
    get:
      tags:
        - Job
      summary: Get job info
      description: Returns detailed information for a specific job.
      operationId: getJobInfo
      parameters:
        - $ref: "#/components/parameters/jobId"
        - name: crawlId
          in: query
          required: false
          description: The crawl ID associated with the job.
          schema:
            type: string
      responses:
        "200":
          description: Job details.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/JobInfo"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /job/{id}/stop:
    get:
      tags:
        - Job
      summary: Stop a running job
      description: Attempts to gracefully stop a running job.
      operationId: stopJob
      parameters:
        - $ref: "#/components/parameters/jobId"
        - name: crawlId
          in: query
          required: false
          description: The crawl ID associated with the job.
          schema:
            type: string
      responses:
        "200":
          description: Whether the job was successfully stopped.
          content:
            application/json:
              schema:
                type: boolean
              example: true
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /job/{id}/abort:
    get:
      tags:
        - Job
      summary: Abort a job
      description: >-
        Forcefully aborts a job. Unlike stop, this kills the job immediately.
      operationId: abortJob
      parameters:
        - $ref: "#/components/parameters/jobId"
        - name: crawlId
          in: query
          required: false
          description: The crawl ID associated with the job.
          schema:
            type: string
      responses:
        "200":
          description: Whether the job was successfully aborted.
          content:
            application/json:
              schema:
                type: boolean
              example: true
        "401":
          $ref: "#/components/responses/Unauthorized"
        "404":
          $ref: "#/components/responses/NotFound"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /job/create:
    post:
      tags:
        - Job
      summary: Create a new job
      description: >-
        Creates and enqueues a new Nutch job (e.g., inject, generate, fetch,
        parse, updatedb, index).
      operationId: createJob
      requestBody:
        required: true
        description: The job configuration specifying type, crawl ID, and arguments.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/JobConfig"
      responses:
        "200":
          description: Job created. Returns the job information.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/JobInfo"
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Database
  # ---------------------------------------------------------------------------
  /db/crawldb:
    post:
      tags:
        - Database
      summary: Query the CrawlDB
      description: >-
        Executes a query against the Nutch CrawlDB. The type field in the
        request body determines the operation: stats, dump, topN, or url.
        The stats and url types return JSON; dump and topN return binary
        octet-stream data.
      operationId: readCrawlDb
      requestBody:
        required: true
        description: The database query parameters.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/DbQuery"
      responses:
        "200":
          description: >-
            Query results. Content type varies by query type: application/json
            for stats and url queries; application/octet-stream for dump and
            topN queries.
          content:
            application/json:
              schema:
                type: object
                description: >-
                  CrawlDB query result (returned for stats and url query
                  types).
            application/octet-stream:
              schema:
                type: string
                format: binary
                description: >-
                  Binary data stream (returned for dump and topN query types).
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /db/fetchdb:
    get:
      tags:
        - Database
      summary: Get FetchDB node information
      description: >-
        Returns fetch node database entries for the specified index range.
        Both from and to default to 0; if to is 0 or exceeds the total
        number of entries, all entries from the starting index are returned.
      operationId: fetchDb
      parameters:
        - name: from
          in: query
          required: false
          description: Starting index (inclusive). Defaults to 0.
          schema:
            type: integer
            format: int32
            minimum: 0
            maximum: 2147483647
            default: 0
        - name: to
          in: query
          required: false
          description: Ending index (inclusive). Defaults to 0 (returns all).
          schema:
            type: integer
            format: int32
            minimum: 0
            maximum: 2147483647
            default: 0
      responses:
        "200":
          description: A JSON array of fetch node information objects.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/FetchNodeDbInfo"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Seed
  # ---------------------------------------------------------------------------
  /seed/:
    get:
      tags:
        - Seed
      summary: List all seed lists
      description: Returns a map of all created seed files keyed by name.
      operationId: getSeedLists
      responses:
        "200":
          description: A JSON object mapping seed list names to SeedList objects.
          content:
            application/json:
              schema:
                type: object
                additionalProperties:
                  $ref: "#/components/schemas/SeedList"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /seed/create:
    post:
      tags:
        - Seed
      summary: Create a seed list file
      description: >-
        Creates a seed list file from the provided URLs and writes it to
        HDFS. Returns the path to the created seed file directory.
      operationId: createSeedFile
      requestBody:
        required: true
        description: The seed list containing URLs to write.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/SeedList"
      responses:
        "200":
          description: Path to the created seed file directory.
          content:
            text/plain:
              schema:
                type: string
              example: "seedFiles/seed-1700000000000"
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Reader
  # ---------------------------------------------------------------------------
  /reader/sequence/read:
    post:
      tags:
        - Reader
      summary: Read a sequence file
      description: >-
        Reads key-value pairs from a Hadoop sequence file. Supports reading
        all rows, a limited number of rows, a row range, or counting the
        total number of rows.
      operationId: seqRead
      parameters:
        - $ref: "#/components/parameters/nrows"
        - $ref: "#/components/parameters/start"
        - $ref: "#/components/parameters/end"
        - $ref: "#/components/parameters/count"
      requestBody:
        required: true
        description: Reader configuration specifying the file path.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/ReaderConfig"
      responses:
        "200":
          description: >-
            Sequence file data. Returns application/json when reading rows,
            or text/plain when count=true.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
            text/plain:
              schema:
                type: integer
                format: int32
                minimum: 0
                maximum: 2147483647
                description: Number of rows in the sequence file.
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /reader/link:
    get:
      tags:
        - Reader
      summary: Get link reader schema
      description: >-
        Returns the schema describing the fields in link reader responses.
      operationId: getLinkSchema
      responses:
        "200":
          description: Link reader response schema.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/LinkSchema"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /reader/link/read:
    post:
      tags:
        - Reader
      summary: Read link objects
      description: >-
        Reads link data (LinkDatum) from the Nutch webgraph. Supports
        reading all rows, a limited number of rows, a row range, or
        counting the total number of rows.
      operationId: linkRead
      parameters:
        - $ref: "#/components/parameters/nrows"
        - $ref: "#/components/parameters/start"
        - $ref: "#/components/parameters/end"
        - $ref: "#/components/parameters/count"
      requestBody:
        required: true
        description: Reader configuration specifying the file path.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/ReaderConfig"
      responses:
        "200":
          description: >-
            Link data. Returns application/json when reading rows, or
            text/plain when count=true.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
            text/plain:
              schema:
                type: integer
                format: int32
                minimum: 0
                maximum: 2147483647
                description: Number of link entries.
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /reader/node:
    get:
      tags:
        - Reader
      summary: Get node reader schema
      description: >-
        Returns the schema describing the fields in node reader responses.
      operationId: getNodeSchema
      responses:
        "200":
          description: Node reader response schema.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/NodeSchema"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /reader/node/read:
    post:
      tags:
        - Reader
      summary: Read node objects
      description: >-
        Reads Node objects from the Nutch webgraph. Supports reading all
        rows, a limited number of rows, a row range, or counting the total
        number of rows.
      operationId: nodeRead
      parameters:
        - $ref: "#/components/parameters/nrows"
        - $ref: "#/components/parameters/start"
        - $ref: "#/components/parameters/end"
        - $ref: "#/components/parameters/count"
      requestBody:
        required: true
        description: Reader configuration specifying the file path.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/ReaderConfig"
      responses:
        "200":
          description: >-
            Node data. Returns application/json when reading rows, or
            text/plain when count=true.
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
            text/plain:
              schema:
                type: integer
                format: int32
                minimum: 0
                maximum: 2147483647
                description: Number of node entries.
        "400":
          $ref: "#/components/responses/BadRequest"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  # ---------------------------------------------------------------------------
  # Services
  # ---------------------------------------------------------------------------
  /services/commoncrawldump/{crawlId}:
    get:
      tags:
        - Services
      summary: List CommonCrawl dump paths
      description: >-
        Lists the dump file paths for a given crawl ID.
      operationId: listDumpPaths
      parameters:
        - name: crawlId
          in: path
          required: true
          description: The crawl ID whose dump paths to list.
          schema:
            type: string
      responses:
        "200":
          description: Service information containing the list of dump paths.
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/ServiceInfo"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

  /services/commoncrawldump:
    post:
      tags:
        - Services
      summary: Create a CommonCrawl data dump
      description: >-
        Executes a CommonCrawl data dump job for the specified crawl and
        returns the output directory path.
      operationId: commoncrawlDump
      requestBody:
        required: true
        description: Service configuration specifying crawl ID and arguments.
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/ServiceConfig"
      responses:
        "200":
          description: The output directory path for the dump.
          content:
            text/plain:
              schema:
                type: string
              example: "myCrawl/dump/commoncrawl-20260213120000"
        "401":
          $ref: "#/components/responses/Unauthorized"
        "500":
          $ref: "#/components/responses/InternalServerError"

# =============================================================================
# Components
# =============================================================================
components:

  # ---------------------------------------------------------------------------
  # Security Schemes
  # ---------------------------------------------------------------------------
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: HTTP Basic Authentication.

  # ---------------------------------------------------------------------------
  # Reusable Parameters
  # ---------------------------------------------------------------------------
  parameters:
    configId:
      name: configId
      in: path
      required: true
      description: The unique identifier for the configuration.
      schema:
        type: string
    propertyId:
      name: propertyId
      in: path
      required: true
      description: The name (key) of the configuration property.
      schema:
        type: string
    jobId:
      name: id
      in: path
      required: true
      description: The unique identifier for the job.
      schema:
        type: string
    nrows:
      name: nrows
      in: query
      required: false
      description: >-
        Number of rows to read. If not specified (or -1), all rows are
        returned.
      schema:
        type: integer
        format: int32
        minimum: -1
        maximum: 2147483647
        default: -1
    start:
      name: start
      in: query
      required: false
      description: Starting line number for a range read.
      schema:
        type: integer
        format: int32
        minimum: -1
        maximum: 2147483647
        default: -1
    end:
      name: end
      in: query
      required: false
      description: Ending line number for a range read.
      schema:
        type: integer
        format: int32
        minimum: 0
        maximum: 2147483647
    count:
      name: count
      in: query
      required: false
      description: >-
        If true, returns the number of lines instead of the data itself.
        When set, the response content type is text/plain.
      schema:
        type: boolean
        default: false

  # ---------------------------------------------------------------------------
  # Schemas
  # ---------------------------------------------------------------------------
  schemas:
    # -- Request Models -------------------------------------------------------
    NutchConfig:
      type: object
      description: Configuration for creating a new Nutch configuration.
      properties:
        configId:
          type: string
          description: The identifier for this configuration.
        force:
          type: boolean
          description: >-
            If true, overwrites an existing configuration with the same ID.
          default: false
        params:
          type: object
          additionalProperties:
            type: string
          description: Key-value pairs of Nutch configuration properties.
      example:
        configId: "my-config"
        force: false
        params:
          http.agent.name: "MyBot"
          http.robots.agents: "MyBot,*"

    JobConfig:
      type: object
      description: Configuration for creating a new crawl job.
      required:
        - type
      properties:
        crawlId:
          type: string
          description: The crawl identifier.
        type:
          $ref: "#/components/schemas/JobType"
        confId:
          type: string
          description: >-
            The configuration ID to use for this job. Defaults to "default"
            if not specified.
        jobClassName:
          type: string
          description: >-
            Fully qualified class name when type is CLASS.
        args:
          type: object
          additionalProperties: true
          description: Additional arguments for the job.
      example:
        crawlId: "crawl-01"
        type: "INJECT"
        confId: "default"
        args:
          seedDir: "seedFiles/seed-1700000000000"

    DbQuery:
      type: object
      description: Parameters for a CrawlDB query.
      required:
        - crawlId
        - type
      properties:
        confId:
          type: string
          description: >-
            Configuration ID. Falls back to "default" if not provided.
        type:
          type: string
          description: The type of CrawlDB query to execute.
          enum:
            - stats
            - dump
            - topN
            - url
        args:
          type: object
          additionalProperties:
            type: string
          description: Additional arguments for the query.
        crawlId:
          type: string
          description: The crawl identifier.
      example:
        confId: "default"
        type: "stats"
        crawlId: "crawl-01"
        args: {}

    ReaderConfig:
      type: object
      description: Configuration specifying a file path for reader operations.
      required:
        - path
      properties:
        path:
          type: string
          description: >-
            The path to the sequence file, link data, or node data to read.
      example:
        path: "crawl-01/crawldb/current/part-00000/data"

    SeedList:
      type: object
      description: A named list of seed URLs.
      required:
        - seedUrls
      properties:
        id:
          type: integer
          format: int64
          minimum: 0
          maximum: 9007199254740991
          description: The seed list identifier.
          readOnly: true
        name:
          type: string
          description: A human-readable name for this seed list.
        seedFilePath:
          type: string
          description: >-
            The HDFS path where the seed file is stored. Populated after
            creation.
          readOnly: true
        seedUrls:
          type: array
          items:
            $ref: "#/components/schemas/SeedUrl"
          description: The collection of seed URLs in this list.
      example:
        name: "my-seeds"
        seedUrls:
          - url: "https://example.com"
          - url: "https://nutch.apache.org"

    SeedUrl:
      type: object
      description: A single seed URL entry.
      properties:
        id:
          type: integer
          format: int64
          minimum: 0
          maximum: 9007199254740991
          description: The seed URL identifier.
          readOnly: true
        url:
          type: string
          description: The seed URL.
      example:
        url: "https://example.com"

    ServiceConfig:
      type: object
      description: >-
        Configuration for service operations such as CommonCrawl data dumps.
      required:
        - crawlId
      properties:
        crawlId:
          type: string
          description: The crawl identifier.
        confId:
          type: string
          description: The configuration ID.
        args:
          type: object
          additionalProperties: true
          description: Additional arguments for the service operation.
      example:
        crawlId: "crawl-01"
        confId: "default"
        args: {}

    # -- Response Models ------------------------------------------------------
    NutchServerInfo:
      type: object
      description: Status information about the running Nutch server.
      required:
        - configuration
        - jobs
        - runningJobs
      properties:
        startDate:
          type: string
          format: date-time
          description: The date and time the server was started.
        configuration:
          type: array
          items:
            type: string
          uniqueItems: true
          description: Set of known configuration IDs.
        jobs:
          type: array
          items:
            $ref: "#/components/schemas/JobInfo"
          description: All jobs (any state).
        runningJobs:
          type: array
          items:
            $ref: "#/components/schemas/JobInfo"
          description: Currently running jobs.

    JobInfo:
      type: object
      description: Information about a crawl job.
      required:
        - type
        - state
      properties:
        id:
          type: string
          description: The unique job identifier.
        type:
          $ref: "#/components/schemas/JobType"
        confId:
          type: string
          description: The configuration ID used for this job.
        args:
          type: object
          additionalProperties: true
          description: Arguments passed to the job.
        result:
          type: object
          additionalProperties: true
          description: Result data returned after job completion.
        state:
          $ref: "#/components/schemas/State"
        msg:
          type: string
          description: A human-readable status or error message.
        crawlId:
          type: string
          description: The crawl identifier associated with this job.

    FetchNodeDbInfo:
      type: object
      description: Information about a fetched node in the FetchDB.
      required:
        - children
      properties:
        url:
          type: string
          description: The URL of the fetched node.
        status:
          type: integer
          format: int32
          minimum: 0
          maximum: 2147483647
          description: The HTTP status code of the fetch.
        numOfOutlinks:
          type: integer
          format: int32
          minimum: 0
          maximum: 2147483647
          description: The number of outgoing links discovered.
        children:
          type: array
          items:
            $ref: "#/components/schemas/ChildNode"
          description: The outgoing links from this node.

    ChildNode:
      type: object
      description: A child (outlink) of a fetched node.
      properties:
        childUrl:
          type: string
          description: The URL of the child node.
        anchorText:
          type: string
          description: The anchor text of the link.

    ServiceInfo:
      type: object
      description: Information returned by service operations.
      required:
        - dumpPaths
      properties:
        dumpPaths:
          type: array
          items:
            type: string
          description: List of file paths for the dump output.

    # -- Schema Objects (Reader) ----------------------------------------------
    LinkSchema:
      type: object
      description: Schema describing the fields in a link reader response.
      properties:
        key_url:
          type: string
          example: "string"
        timestamp:
          type: string
          example: "int"
        score:
          type: string
          example: "float"
        anchor:
          type: string
          example: "string"
        linktype:
          type: string
          example: "string"
        url:
          type: string
          example: "string"

    NodeSchema:
      type: object
      description: Schema describing the fields in a node reader response.
      properties:
        key_url:
          type: string
          example: "string"
        num_inlinks:
          type: string
          example: "int"
        num_outlinks:
          type: string
          example: "int"
        inlink_score:
          type: string
          example: "float"
        outlink_score:
          type: string
          example: "float"
        metadata:
          type: string
          example: "string"

    # -- Enums ----------------------------------------------------------------
    JobType:
      type: string
      description: The type of Nutch crawl job.
      enum:
        - INJECT
        - GENERATE
        - FETCH
        - PARSE
        - UPDATEDB
        - INDEX
        - READDB
        - CLASS
        - INVERTLINKS
        - DEDUP

    State:
      type: string
      description: The current state of a job.
      enum:
        - IDLE
        - RUNNING
        - FINISHED
        - FAILED
        - KILLED
        - STOPPING
        - KILLING
        - ANY

  # ---------------------------------------------------------------------------
  # Reusable Responses
  # ---------------------------------------------------------------------------
  responses:
    BadRequest:
      description: >-
        Bad request. The request body is missing, malformed, or contains
        invalid parameters.
      content:
        text/plain:
          schema:
            type: string
          example: "Nutch configuration cannot be empty!"

    Unauthorized:
      description: >-
        Unauthorized. Basic authentication credentials are missing or
        invalid.
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
            example:
              message: "Authentication required."

    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            type: object
            properties:
              message:
                type: string
            example:
              message: "Resource not found."

    InternalServerError:
      description: An unexpected server error occurred.
      content:
        text/plain:
          schema:
            type: string
          example: "Internal server error."