import Foundation
import SwiftUI
import UniformTypeIdentifiers

@MainActor
	final class ImportFlowViewModel: ObservableObject {
	@Published var template = MoodwellStateOfMindTemplate.template
	@Published var entries: [MoodwellEntry] = []
	@Published var sourceKeys: [String] = []
	@Published var mapping = MoodwellStateOfMindTemplate.defaultMapping
	@Published var moodValenceScale: [Int: Double] = [1: -0.8, 2: -0.25, 3: 0.3, 4: 0.8]
	@Published var dryRunResult: DryRunResult?
	@Published var isImporting = false
	@Published var statusMessage = ""
	@Published var errorMessage: String?

	let supportedContentTypes: [UTType] = [.json]

	private let healthKitService = HealthKitService()

	init() {
		loadBundledSample()
	}

	func loadBundledSample() {
		guard let url = Bundle.main.url(forResource: "MoodwellData", withExtension: "json") else {
			errorMessage = String(localized: "error.sample.missing")
			return
		}
		loadFile(from: url)
	}

		func loadFile(from url: URL) {
			do {
			let data = try Data(contentsOf: url)
			let payload = try JSONDecoder().decode(MoodwellPayload.self, from: data)
			entries = payload.mymoods
			if let firstEntry = payload.mymoods.first {
				sourceKeys = Array(firstEntry.sourceDictionary.keys).sorted()
			} else {
				sourceKeys = []
				}
				dryRunResult = nil
				statusMessage = String.localizedStringWithFormat(
					NSLocalizedString("status.loaded", comment: ""),
					entries.count
				)
				errorMessage = nil
			} catch {
				errorMessage = String(localized: "error.load.file") + " \(error.localizedDescription)"
			}
		}

		func runDryRun() {
			let result = MoodwellStateOfMindTemplate.makeDrafts(entries: entries, mapping: mapping, moodValenceScale: moodValenceScale)
			dryRunResult = result
			if result.errors.isEmpty {
				statusMessage = String.localizedStringWithFormat(
					NSLocalizedString("status.dryrun.success", comment: ""),
					result.drafts.count
				)
			} else {
				statusMessage = String.localizedStringWithFormat(
					NSLocalizedString("status.dryrun.withErrors", comment: ""),
					result.errors.count
				)
			}
		}

	func commitImport() async {
		guard let dryRunResult else {
			errorMessage = String(localized: "error.dryrun.required")
			return
		}
		guard dryRunResult.errors.isEmpty else {
			errorMessage = String(localized: "error.dryrun.fix")
			return
		}

		isImporting = true
		defer { isImporting = false }

			do {
				try await healthKitService.requestWriteAccessForStateOfMind()
				try await healthKitService.save(dryRunResult.drafts)
				statusMessage = String.localizedStringWithFormat(
					NSLocalizedString("status.import.success", comment: ""),
					dryRunResult.drafts.count
				)
				errorMessage = nil
			} catch {
			errorMessage = String(localized: "error.import.failed") + " \(error.localizedDescription)"
		}
	}
}