//// Public API: turn a set of parsed `atproto_lexicon/ast.LexiconDoc`
//// values into a single OpenAPI 3.1.0 document. See
//// `docs/lexicon-openapi.md` for the mapping this implements and
//// `atproto_openapi/emit` for the assembly logic this delegates to.
//// `main` runs the CLI (`atproto_openapi/cli`), which walks a directory of
//// lexicon JSON files and writes the generated document to disk.

import atproto_lexicon/ast.{type LexiconDoc}
import atproto_openapi/cli
import atproto_openapi/emit
import atproto_openapi/refs
import gleam/json
import gleam/result

/// Per-run document metadata. A CLI invocation fills this from flags with
/// sane defaults; a library caller builds it directly.
pub type Options {
  Options(title: String, version: String, servers: List(String))
}

pub type Generated {
  Generated(
    json: String,
    operation_count: Int,
    schema_count: Int,
    subscriptions_skipped: List(String),
  )
}

pub type Error {
  RefError(refs.RefError)
}

/// Assemble `docs` into one OpenAPI 3.1.0 document. Fails only when a ref
/// is malformed or two distinct lexicon refs derive the same
/// `components/schemas` key; see `atproto_openapi/refs`. Every other input
/// shape has a defined mapping per the design doc.
pub fn generate(
  docs: List(LexiconDoc),
  options: Options,
) -> Result(Generated, Error) {
  emit.assemble(docs, options.title, options.version, options.servers)
  |> result.map(fn(document) {
    Generated(
      json: json.to_string(document.json),
      operation_count: document.operation_count,
      schema_count: document.schema_count,
      subscriptions_skipped: document.subscriptions_skipped,
    )
  })
  |> result.map_error(RefError)
}

/// `gleam run -m atproto_openapi -- <lexicons-dir> <out-file> [--title T]
/// [--version V] [--server URL]`. See `atproto_openapi/cli`.
pub fn main() -> Nil {
  cli.main()
}