//
//  ThumbnailProvider.swift
//  honeyDueQLThumbnail
//
//  Created by Trey Tartt on 12/6/25.
//

import UIKit
import QuickLookThumbnailing

class ThumbnailProvider: QLThumbnailProvider {

    /// Represents the type of .honeydue package
    private enum PackageType {
        case contractor
        case residence
    }

    override func provideThumbnail(for request: QLFileThumbnailRequest, _ handler: @escaping (QLThumbnailReply?, Error?) -> Void) {

        let thumbnailSize = request.maximumSize

        // Detect package type from file
        let packageType = detectPackageType(at: request.fileURL)

        handler(QLThumbnailReply(contextSize: thumbnailSize, currentContextDrawing: { () -> Bool in
            // Draw background
            let backgroundColor = UIColor(red: 7/255, green: 160/255, blue: 195/255, alpha: 1)
            backgroundColor.setFill()
            UIRectFill(CGRect(origin: .zero, size: thumbnailSize))

            // Choose icon based on package type
            let iconName: String
            switch packageType {
            case .contractor:
                iconName = "person.crop.rectangle.stack"
            case .residence:
                iconName = "house.fill"
            }

            // Draw icon
            let config = UIImage.SymbolConfiguration(pointSize: min(thumbnailSize.width, thumbnailSize.height) * 0.5, weight: .regular)
            if let icon = UIImage(systemName: iconName, withConfiguration: config) {
                let tintedIcon = icon.withTintColor(.white, renderingMode: .alwaysOriginal)
                let iconSize = tintedIcon.size
                let iconOrigin = CGPoint(
                    x: (thumbnailSize.width - iconSize.width) / 2,
                    y: (thumbnailSize.height - iconSize.height) / 2
                )
                tintedIcon.draw(at: iconOrigin)
            }

            return true
        }), nil)
    }

    /// Lightweight struct to detect the package type via Codable instead of JSONSerialization
    private struct PackageTypeEnvelope: Decodable {
        let type: String?
    }

    /// Detects the package type by reading the "type" field from the JSON
    private func detectPackageType(at url: URL) -> PackageType {
        do {
            let data = try Data(contentsOf: url)
            let envelope = try JSONDecoder().decode(PackageTypeEnvelope.self, from: data)
            if envelope.type == "residence" {
                return .residence
            }
        } catch {
            // Default to contractor on error
        }
        return .contractor
    }
}