@startuml gh_aw_dataset_v0_1_er
title gh-aw-dataset-builder ER

hide circle
skinparam linetype ortho
skinparam entity {
  BackgroundColor White
  BorderColor #2F5D7C
}

entity "repository" as repository {
  * repository_id : int64 <<PK>>
  --
  url : string
  license : string
  repo_full_name : string
  repo_owner : string
  repo_name : string
  main_language : string
  forks : int64
  stars : int64
  created_at : string
  updated_at : string
  pushed_at : string
}

entity "source_markdown_file_history" as source_markdown_file_history {
  * source_markdown_file_history_id : int64 <<PK>>
  --
  version_count : int64
}

entity "source_markdown_file_version" as source_markdown_file_version {
  * source_markdown_file_version_id : int64 <<PK>>
  --
  * source_markdown_file_history_id : int64 <<FK>>
  * source_markdown_file_snapshot_id : int64 <<FK>>
  commit_sha : string
  committed_at : string
  rank : int64
  predecessor_source_markdown_file_version_id : int64
  successor_source_markdown_file_version_id : int64
}

entity "source_markdown_file_snapshot" as source_markdown_file_snapshot {
  * source_markdown_file_snapshot_id : int64 <<PK>>
  --
  * repository_id : int64 <<FK>>
  path : string
  content : string
  frontmatter : string
  body : string
}

entity "lock_file_snapshot" as lock_file_snapshot {
  * lock_file_snapshot_id : int64 <<PK>>
  --
  * source_markdown_file_version_id : int64 <<FK>>
  path : string
  content : string
  file_sha : string
}

repository ||--|{ source_markdown_file_snapshot : "1 -> 1..N"
source_markdown_file_snapshot ||--|| source_markdown_file_version : "1 -> 1"
source_markdown_file_history ||--|{ source_markdown_file_version : "1 -> 1..N"
source_markdown_file_version ||--|| lock_file_snapshot : "1 -> 1"

note right of repository
  repository_id is the internal dataset PK.

  created_at, updated_at, and pushed_at are
  GitHub repository API timestamps.
end note

note right of source_markdown_file_history
  source_history groups versions.
  Path is obtained through version -> snapshot.
end note

note right of source_markdown_file_snapshot
  First observable source_history fact
  from repository.
end note

note right of lock_file_snapshot
  Lock artifact snapshot aligned to the
  source Markdown version commit.

  Published source_history requires
  exactly one lock snapshot per version.
end note

@enduml