import Foundation

struct GeminiJSONLParser: ImportParser {
    func parse(sourceURL: URL, dedupIndex: DedupIndex) throws -> ImportParseResult {
        let files = try ImportFiles.immediateFiles(
            at: sourceURL,
            expected: "eine Gemini-.jsonl-Datei oder einen Ordner mit .jsonl-Dateien",
            directFileMatches: { $0.pathExtension.lowercased() == "jsonl" },
            directoryFileMatches: { $0.pathExtension.lowercased() == "jsonl" }
        )
        var accumulator = ImportAccumulator(
            minimumLength: 20,
            maximumLength: 10_000,
            dedupIndex: dedupIndex
        )

        for fileURL in files {
            let notebook = fileURL.deletingPathExtension().lastPathComponent
            for line in try ImportFiles.lines(from: fileURL) {
                let root: Any
                do {
                    root = try ImportJSON.object(fromLine: line)
                } catch {
                    accumulator.skipMalformed()
                    continue
                }
                guard let object = root as? [String: Any] else {
                    accumulator.skipMalformed()
                    continue
                }
                guard object["role"] as? String == "user" else { continue }
                let text: String
                if object["content"] == nil {
                    // Python's obj.get("content", "") treats a missing value
                    // as an empty prompt, which is scanned and skipped_short.
                    text = ""
                } else if let content = object["content"] as? String {
                    text = content
                } else {
                    accumulator.skipMalformed()
                    continue
                }

                accumulator.accept(
                    text,
                    sourcePrefix: "gemini-raw",
                    tags: "gemini,\(notebook.lowercased())",
                    promptedAt: firstTimestamp(in: object)
                )
            }
        }

        return accumulator.result()
    }

    private func firstTimestamp(in object: [String: Any]) -> String? {
        for key in ["timestamp", "date", "created_at", "create_time"] {
            if let timestamp = ImportTimestamp.normalize(object[key]) {
                return timestamp
            }
        }
        return nil
    }
}