import Foundation
import SwiftParser
import SwiftSyntax

extension Scanner {
  /// Runs `scan-exports` over `paths`, prints the JSON report to stdout, and returns the exit code
  /// (`0` on success, `1` if encoding fails). The deep counterpart to `runModules`.
  public static func runExports(paths: [String]) -> Int32 {
    let result = scanExports(paths: paths)

    do {
      let encoder = JSONEncoder()
      encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
      let data = try encoder.encode(result)
      FileHandle.standardOutput.write(data)
      FileHandle.standardOutput.write(Data("\n".utf8))
      return 0
    } catch {
      FileHandle.standardError.write(Data("error: failed to encode results: \(error)\n".utf8))
      return 1
    }
  }
}

/// Scans `paths` for `@ExpoModule`, `@SharedObject`, and `@Record` types and returns their exported
/// surface plus the run's stats. Separate from the public entry so tests can drive it without
/// argv/stdout. The shared `scanFiles` walk + pre-filter selects files; a `SurfaceVisitor` extracts
/// each one.
func scanExports(paths: [String]) -> ScanExportsResult {
  var modules: [ExportedModule] = []
  var sharedObjects: [ExportedSharedObject] = []
  var records: [ExportedRecord] = []

  let stats = scanFiles(paths: paths, macros: [.expoModule, .sharedObject, .record]) { source, file in
    let tree = Parser.parse(source: source)
    let visitor = SurfaceVisitor(file: file)
    visitor.walk(tree)
    modules.append(contentsOf: visitor.modules)
    sharedObjects.append(contentsOf: visitor.sharedObjects)
    records.append(contentsOf: visitor.records)
  }

  return ScanExportsResult(
    exports: ExportedSurface(modules: modules, sharedObjects: sharedObjects, records: records),
    stats: stats
  )
}