{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:opencourse:course:1.8",
  "title": "OpenCourse course manifest v1.8",
  "type": "object",
  "required": [
    "schema_version",
    "slug",
    "title",
    "modules"
  ],
  "additionalProperties": false,
  "properties": {
    "schema_version": {
      "enum": [
        "1.0",
        "1.1",
        "1.2",
        "1.3",
        "1.4",
        "1.5",
        "1.6",
        "1.7",
        "1.8"
      ]
    },
    "slug": {
      "$ref": "#/$defs/slug"
    },
    "title": {
      "type": "string",
      "minLength": 1
    },
    "version": {
      "$ref": "#/$defs/courseVersion"
    },
    "uid": {
      "$ref": "#/$defs/uid"
    },
    "description": {
      "type": "string"
    },
    "author": {
      "type": "string"
    },
    "difficulty": {
      "enum": [
        "beginner",
        "intermediate",
        "advanced"
      ]
    },
    "estimated_hours": {
      "type": "integer",
      "minimum": 0
    },
    "subject": {
      "type": "string",
      "minLength": 1
    },
    "runtime": {
      "$ref": "#/$defs/runtime"
    },
    "python_version": {
      "type": "string",
      "minLength": 1,
      "pattern": "^(?:>=\\s*)?\\d+\\.\\d+(?:\\.\\d+)?$"
    },
    "prerequisites": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "tags": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "cover_image": {
      "$ref": "#/$defs/assetPath"
    },
    "modules": {
      "type": "array",
      "minItems": 1,
      "items": {
        "$ref": "#/$defs/module"
      }
    },
    "notebook": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "cells": {
          "type": "array",
          "maxItems": 500,
          "items": {
            "type": "object",
            "required": [
              "content"
            ],
            "additionalProperties": false,
            "properties": {
              "content": {
                "type": "string",
                "maxLength": 1048576
              }
            }
          }
        }
      }
    }
  },
  "$defs": {
    "courseVersion": {
      "type": "string",
      "pattern": "^(0|[1-9][0-9]{0,8})\\.(0|[1-9][0-9]{0,8})\\.(0|[1-9][0-9]{0,8})$",
      "description": "The course's own version, MAJOR.MINOR.PATCH. Required from schema 1.5. A server only accepts a version higher than any it has published for the course."
    },
    "uid": {
      "type": "string",
      "pattern": "^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$",
      "description": "Server identity (UUID v4). Present on every element of an archive served by an OpenCourse server, so progress follows elements across versions. Ignored, and replaced, when an archive is imported as a local course; never written by Export ZIP."
    },
    "slug": {
      "type": "string",
      "pattern": "^[a-z0-9]+(?:-[a-z0-9]+)*$"
    },
    "runtime": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "language": {
          "enum": [
            "python"
          ]
        },
        "version": {
          "type": "string",
          "minLength": 1,
          "pattern": "^(?:>=\\s*)?\\d+\\.\\d+(?:\\.\\d+)?$"
        },
        "packages": {
          "type": "array",
          "items": {
            "type": "string",
            "minLength": 1
          }
        },
        "flags": {
          "type": "array",
          "items": {
            "type": "string",
            "minLength": 1
          }
        }
      },
      "description": "Python exercises use the bundled interpreter. version is a minimum; packages are pip requirements. Projects manage their own tools."
    },
    "extraFilePath": {
      "type": "string",
      "minLength": 1,
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._-]*(?:/[A-Za-z0-9][A-Za-z0-9._-]*)*$",
      "not": {
        "pattern": "\\.[cC][oO][mM][mM][aA][nN][dD]$"
      },
      "description": "Relative to the exercise directory. Every segment must start with a letter or digit, which rules out '..', absolute paths and dotfiles."
    },
    "extraFile": {
      "type": "object",
      "required": [
        "path",
        "content"
      ],
      "additionalProperties": false,
      "properties": {
        "path": {
          "$ref": "#/$defs/extraFilePath"
        },
        "content": {
          "type": "string"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "assetPath": {
      "type": "string",
      "minLength": 1,
      "not": {
        "pattern": "(^/)|(^[a-zA-Z]:)|(\\.\\.)|(^~)"
      },
      "description": "Relative to the course root. No absolute paths, no '..' segments."
    },
    "lesson": {
      "type": "object",
      "required": [
        "slug",
        "title",
        "blocks"
      ],
      "additionalProperties": false,
      "properties": {
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "title": {
          "type": "string",
          "minLength": 1
        },
        "objectives": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "estimated_minutes": {
          "type": "integer",
          "minimum": 1,
          "maximum": 600
        },
        "blocks": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/block"
          }
        },
        "flashcards": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/flashcard"
          }
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "block": {
      "oneOf": [
        {
          "$ref": "#/$defs/blockMarkdown"
        },
        {
          "$ref": "#/$defs/blockImage"
        },
        {
          "$ref": "#/$defs/blockVideo"
        },
        {
          "$ref": "#/$defs/blockVisualization"
        },
        {
          "$ref": "#/$defs/blockQuiz"
        },
        {
          "$ref": "#/$defs/blockExercise"
        },
        {
          "$ref": "#/$defs/pythonCell"
        }
      ]
    },
    "blockMarkdown": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "content"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "markdown"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "content": {
          "type": "string"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "blockImage": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "src"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "image"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "src": {
          "$ref": "#/$defs/assetPath"
        },
        "alt": {
          "type": "string"
        },
        "caption": {
          "type": "string"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        },
        "attribution": {
          "$ref": "#/$defs/imageAttribution"
        }
      }
    },
    "blockVideo": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "src"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "video"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "src": {
          "$ref": "#/$defs/assetPath"
        },
        "poster": {
          "$ref": "#/$defs/assetPath"
        },
        "caption": {
          "type": "string"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "blockVisualization": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "src"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "visualization"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "src": {
          "$ref": "#/$defs/assetPath"
        },
        "title": {
          "type": "string"
        },
        "height": {
          "type": "integer",
          "minimum": 100,
          "maximum": 2000
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "blockQuiz": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "id",
        "kind",
        "question"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "quiz"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "id": {
          "type": "string",
          "minLength": 1
        },
        "kind": {
          "enum": [
            "single",
            "multiple",
            "text"
          ]
        },
        "question": {
          "type": "string",
          "minLength": 1
        },
        "options": {
          "type": "array",
          "minItems": 2,
          "items": {
            "$ref": "#/$defs/quizOption"
          }
        },
        "answers": {
          "type": "array",
          "minItems": 1,
          "items": {
            "type": "string"
          }
        },
        "explanation": {
          "type": "string"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      },
      "allOf": [
        {
          "if": {
            "properties": {
              "kind": {
                "enum": [
                  "single",
                  "multiple"
                ]
              }
            }
          },
          "then": {
            "required": [
              "options"
            ]
          }
        },
        {
          "if": {
            "properties": {
              "kind": {
                "const": "text"
              }
            }
          },
          "then": {
            "required": [
              "answers"
            ]
          }
        }
      ]
    },
    "quizOption": {
      "type": "object",
      "required": [
        "id",
        "text",
        "correct"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "minLength": 1
        },
        "text": {
          "type": "string"
        },
        "correct": {
          "type": "boolean"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "blockExercise": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "id",
        "title",
        "prompt",
        "verification_instructions"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "exercise"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "id": {
          "type": "string",
          "minLength": 1
        },
        "title": {
          "type": "string",
          "minLength": 1
        },
        "prompt": {
          "type": "string",
          "minLength": 1
        },
        "runtime": {
          "$ref": "#/$defs/runtime"
        },
        "starter_code": {
          "type": "string"
        },
        "solution": {
          "type": "string"
        },
        "tests": {
          "type": "string"
        },
        "test_command": {
          "type": "string",
          "minLength": 1
        },
        "extra_files": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/extraFile"
          }
        },
        "expected_output": {
          "type": "string"
        },
        "stdin": {
          "type": "string"
        },
        "match": {
          "enum": [
            "exact",
            "trimmed",
            "lines"
          ]
        },
        "packages": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "verification_instructions": {
          "type": "string"
        },
        "hints": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "lessonModule": {
      "type": "object",
      "required": [
        "slug",
        "title",
        "lessons"
      ],
      "additionalProperties": false,
      "properties": {
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "title": {
          "type": "string",
          "minLength": 1
        },
        "lessons": {
          "type": "array",
          "minItems": 1,
          "items": {
            "$ref": "#/$defs/lesson"
          }
        },
        "type": {
          "const": "lessons"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "module": {
      "oneOf": [
        {
          "$ref": "#/$defs/lessonModule"
        },
        {
          "$ref": "#/$defs/projectModule"
        }
      ]
    },
    "projectModule": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "title",
        "project"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "project"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "title": {
          "type": "string",
          "minLength": 1,
          "maxLength": 500
        },
        "project": {
          "$ref": "#/$defs/projectDefinition"
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "projectDefinition": {
      "type": "object",
      "required": [
        "definition",
        "requirements",
        "deliverables"
      ],
      "additionalProperties": false,
      "properties": {
        "definition": {
          "type": "string",
          "minLength": 1,
          "maxLength": 20000
        },
        "objectives": {
          "type": "array",
          "minItems": 1,
          "maxItems": 30,
          "items": {
            "type": "string",
            "minLength": 1,
            "maxLength": 1000
          }
        },
        "estimated_minutes": {
          "type": "integer",
          "minimum": 1,
          "maximum": 10000
        },
        "requirements": {
          "type": "array",
          "minItems": 1,
          "maxItems": 50,
          "items": {
            "type": "object",
            "required": [
              "id",
              "description"
            ],
            "additionalProperties": false,
            "properties": {
              "id": {
                "$ref": "#/$defs/slug"
              },
              "description": {
                "type": "string",
                "minLength": 1,
                "maxLength": 2000
              },
              "uid": {
                "$ref": "#/$defs/uid"
              }
            }
          }
        },
        "deliverables": {
          "type": "array",
          "minItems": 1,
          "maxItems": 30,
          "items": {
            "type": "object",
            "required": [
              "id",
              "title",
              "description",
              "acceptance_criteria"
            ],
            "additionalProperties": false,
            "properties": {
              "id": {
                "$ref": "#/$defs/slug"
              },
              "title": {
                "type": "string",
                "minLength": 1,
                "maxLength": 500
              },
              "description": {
                "type": "string",
                "minLength": 1,
                "maxLength": 2000
              },
              "paths": {
                "type": "array",
                "minItems": 1,
                "maxItems": 30,
                "items": {
                  "$ref": "#/$defs/extraFilePath"
                }
              },
              "acceptance_criteria": {
                "type": "array",
                "minItems": 1,
                "maxItems": 30,
                "items": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 1000
                }
              },
              "uid": {
                "$ref": "#/$defs/uid"
              }
            }
          }
        },
        "starter_files": {
          "type": "array",
          "maxItems": 100,
          "items": {
            "$ref": "#/$defs/extraFile"
          }
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "flashcard": {
      "type": "object",
      "required": [
        "id",
        "question",
        "answer"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "pattern": "\\S"
        },
        "question": {
          "type": "string",
          "pattern": "\\S"
        },
        "answer": {
          "type": "string",
          "pattern": "\\S"
        },
        "image": {
          "type": "object",
          "required": [
            "src"
          ],
          "additionalProperties": false,
          "properties": {
            "src": {
              "$ref": "#/$defs/assetPath"
            },
            "alt": {
              "type": "string"
            }
          }
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "pythonCell": {
      "type": "object",
      "required": [
        "type",
        "slug",
        "content"
      ],
      "additionalProperties": false,
      "properties": {
        "type": {
          "const": "python-cell"
        },
        "slug": {
          "$ref": "#/$defs/slug"
        },
        "content": {
          "type": "string",
          "maxLength": 1048576
        },
        "uid": {
          "$ref": "#/$defs/uid"
        }
      }
    },
    "imageAttribution": {
      "type": "object",
      "required": [
        "source_url"
      ],
      "additionalProperties": false,
      "properties": {
        "source_url": {
          "type": "string",
          "minLength": 1,
          "maxLength": 2048,
          "pattern": "^https?://[^\\s]+$"
        },
        "title": {
          "type": "string",
          "minLength": 1,
          "maxLength": 1000
        },
        "author": {
          "type": "string",
          "minLength": 1,
          "maxLength": 1000
        },
        "author_url": {
          "type": "string",
          "minLength": 1,
          "maxLength": 2048,
          "pattern": "^https?://[^\\s]+$"
        },
        "license": {
          "type": "string",
          "minLength": 1,
          "maxLength": 1000
        },
        "license_url": {
          "type": "string",
          "minLength": 1,
          "maxLength": 2048,
          "pattern": "^https?://[^\\s]+$"
        }
      }
    }
  },
  "if": {
    "properties": {
      "schema_version": {
        "enum": [
          "1.5",
          "1.6",
          "1.7",
          "1.8"
        ]
      }
    },
    "required": [
      "schema_version"
    ]
  },
  "then": {
    "required": [
      "version"
    ]
  },
  "allOf": [
    {
      "if": {
        "properties": {
          "schema_version": {
            "enum": [
              "1.0",
              "1.1",
              "1.2",
              "1.3",
              "1.4",
              "1.5",
              "1.6"
            ]
          }
        },
        "required": [
          "schema_version"
        ]
      },
      "then": {
        "properties": {
          "notebook": false,
          "modules": {
            "items": {
              "properties": {
                "lessons": {
                  "items": {
                    "properties": {
                      "blocks": {
                        "items": {
                          "not": {
                            "properties": {
                              "type": {
                                "const": "python-cell"
                              }
                            },
                            "required": [
                              "type"
                            ]
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  ]
}