// MacDictationPipeline.swift
// OSGKeyboard · Mac
//
// Dictation pipeline: samples → ASR (cloud or local) → polish.
// Cloud path reuses `CloudASRClientFactory`; local path uses Qwen3-ASR (MLX)
// with Apple Speech fallback when weights are missing.

import Foundation

enum MacDictationError: Error, LocalizedError {
    case noAudio
    case providerHasNoCloudASR
    case emptyTranscript

    var errorDescription: String? {
        switch self {
        case .noAudio:
            return MacL10n.string("mac.error.noAudio")
        case .providerHasNoCloudASR:
            return MacL10n.string("mac.error.noCloudASR")
        case .emptyTranscript:
            return MacL10n.string("mac.error.emptyTranscript")
        }
    }
}

enum MacDictationPipeline {
    /// Runs ASR then best-effort polish. Polish failures fall back to raw text.
    static func run(samples: [Float], store: AppGroupStore) async throws -> String {
        guard !samples.isEmpty else { throw MacDictationError.noAudio }

        let locale = Locale(identifier: store.localeId.isEmpty ? "zh-CN" : store.localeId)
        let raw: String

        if store.engineMode == "local" {
            raw = try await MacLocalASRService.transcribe(samples: samples, locale: locale)
        } else {
            let strategy = CloudASRModelCatalog.strategy(for: store.providerId)
            guard strategy != .localFallback else { throw MacDictationError.providerHasNoCloudASR }

            let client = CloudASRClientFactory.make(store: store)
            try? await client.prepare(dictionary: store.personalDictionary)
            raw = try await client.transcribe(
                samples: samples,
                sampleRate: 16_000,
                locale: locale,
                dictionary: store.personalDictionary
            )
        }

        let trimmed = raw.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !trimmed.isEmpty else { throw MacDictationError.emptyTranscript }

        if let polished = try? await PolishingService(store: store).polish(
            trimmed,
            mode: store.polishModeForPipeline
        ),
           !polished.isEmpty {
            return polished
        }
        return trimmed
    }
}