import Foundation
import AppKit
import SwiftData

class VoiceInkCSVExportService {
    
    func exportTranscriptionsToCSV(transcriptions: [Transcription]) {
        let csvString = generateCSV(for: transcriptions)
        
        let savePanel = NSSavePanel()
        savePanel.allowedContentTypes = [.commaSeparatedText]
        savePanel.nameFieldStringValue = "VoiceInk-transcription.csv"
        
        savePanel.begin { result in
            if result == .OK, let url = savePanel.url {
                do {
                    try csvString.write(to: url, atomically: true, encoding: .utf8)
                } catch {
                    print("Error writing CSV file: \(error)")
                }
            }
        }
    }
    
    private func generateCSV(for transcriptions: [Transcription]) -> String {
        var csvString = "Original Transcript,Enhanced Transcript,Enhancement Model,Prompt Name,Transcription Model,Power Mode,Enhancement Time,Transcription Time,Timestamp,Duration\n"

        for transcription in transcriptions {
            let originalText = escapeCSVString(transcription.text)
            let enhancedText = escapeCSVString(transcription.enhancedText ?? "")
            let enhancementModel = escapeCSVString(transcription.aiEnhancementModelName ?? "")
            let promptName = escapeCSVString(transcription.promptName ?? "")
            let transcriptionModel = escapeCSVString(transcription.transcriptionModelName ?? "")
            let powerMode = escapeCSVString(powerModeDisplay(name: transcription.powerModeName, emoji: transcription.powerModeEmoji))
            let enhancementTime = transcription.enhancementDuration ?? 0
            let transcriptionTime = transcription.transcriptionDuration ?? 0
            let timestamp = transcription.timestamp.ISO8601Format()
            let duration = transcription.duration

            let row = "\(originalText),\(enhancedText),\(enhancementModel),\(promptName),\(transcriptionModel),\(powerMode),\(enhancementTime),\(transcriptionTime),\(timestamp),\(duration)\n"
            csvString.append(row)
        }

        return csvString
    }

    private func escapeCSVString(_ string: String) -> String {
        let escapedString = string.replacingOccurrences(of: "\"", with: "\"\"")
        if escapedString.contains(",") || escapedString.contains("\n") {
            return "\"\(escapedString)\""
        }
        return escapedString
    }

    private func powerModeDisplay(name: String?, emoji: String?) -> String {
        switch (emoji?.trimmingCharacters(in: .whitespacesAndNewlines), name?.trimmingCharacters(in: .whitespacesAndNewlines)) {
        case let (.some(emojiValue), .some(nameValue)) where !emojiValue.isEmpty && !nameValue.isEmpty:
            return "\(emojiValue) \(nameValue)"
        case let (.some(emojiValue), _) where !emojiValue.isEmpty:
            return emojiValue
        case let (_, .some(nameValue)) where !nameValue.isEmpty:
            return nameValue
        default:
            return ""
        }
    }
}