// p4rse, Copyright 2026, Will Hawkins
//
// This file is part of p4rse.
//
// This file is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

import Common
import SwiftTreeSitter

extension CST.Program: Parsable {
  public typealias C = CST.Program
  public static func Parse(
    node: Node, withContext context: CSTCompilerContext
  ) -> Common.Result<CST.Program> {

    var statements: [CST.Statement] = Array()

    var errors: (any Errorable)? = .none

    // Try to parse all top-level declarations.
    node.enumerateNamedChildren { (declaration_node: Node) in
      let declaration_parsers: [String: ParsableStatement.Type] = [
        "declaration": CST.Declaration.self,
        "instantiation": CST.Instantiation.self,
      ]

      if let parser = declaration_parsers[declaration_node.nodeType!] {
        let r = parser.ParseStatement(node: declaration_node, withContext: context)
        switch r {
        case .Ok(let compiled):
          statements.append(compiled)
        case .Error(let e):
          errors =
            if let errors = errors {
              errors.append(error: e)
            } else {
              e
            }

        }
      } else {
        let e = ErrorWithLocation(
          sourceLocation: declaration_node.toSourceLocation(),
          withError:
            "\(declaration_node.nodeType!) cannot be at a P4 program top level")
        errors =
          if let errors = errors {
            errors.append(error: e)
          } else {
            e
          }
      }
    }

    if let errors = errors {
      return .Error(errors)
    }
    return Result.Ok(CST.Program(CST.Statements(statements)))

  }
}