// SPDX-FileCopyrightText: 2025 The Project Pterodactyl Developers
//
// SPDX-License-Identifier: MPL-2.0

import LanguageServerProtocol
import PterodactylBuild
import TSCBasic
import llbuild2fx

actor SourceTreeManager {
	private let buildEngine: FXEngine
	private let casClient: LLBCASFSClient
	private let casContext: TSCUtility.Context
	private(set) var sourceTree: LLBCASFileTree

	init(buildEngine: FXEngine, casClient: LLBCASFSClient, casContext: TSCUtility.Context, sourceTree: LLBCASFileTree? = nil) async throws {
		self.buildEngine = buildEngine
		self.casClient = casClient
		self.casContext = casContext
		if let sourceTree {
			self.sourceTree = sourceTree
		} else {
			self.sourceTree = try await casClient.storeDir(.dir([:]), casContext).get()
		}
	}

	func setBufferText(uri: DocumentUri, text: String) async throws {
		let path = try AbsolutePath.fromDocumentUri(uri)
		let singletonDeclTree = LLBDeclFileTree.file(absolutePath: path, contents: text)
		let singletonTree: LLBCASFileTree = try await casClient.storeDir(singletonDeclTree, casContext).get()
		self.sourceTree = try await sourceTree.merge(with: singletonTree, in: casClient.db, casContext).get()
	}

	func getBufferText(uri: DocumentUri) async throws -> String? {
		let path = try AbsolutePath.fromDocumentUri(uri)
		guard let (id, _) = try await sourceTree.lookup(path: path, in: casClient.db, casContext).get() else { return nil }
		return try await buildEngine.build(key: Keys.Blob.ReadContents(blobId: id), casContext).get()
	}
}