//
//  CaptureContext.swift
//  Focale
//
//  Author: Simon-Pierre Boucher
//  Contact: contact@spboucher.ai
//
//  The differentiating piece of the whole project (CLAUDE.md §4):
//  everything we know about a photo at the moment the shutter fires,
//  captured for free, with zero inference cost.
//

import Foundation

/// Context recorded at shutter time. Written both to the local index and
/// into the asset's own metadata, so the information survives an uninstall.
struct CaptureContext: Codable, Sendable {
    var recipe: Recipe.ID?          // active preset
    var project: Project.ID?        // project declared by the user
    var projectName: String?        // denormalized for metadata embedding
    var subjectHint: String?        // typed or dictated before/after the shot
    var settings: ManualSettings    // ISO, shutter, lens, focus
    var scene: SceneSignal          // luminance, motion, distance (LiDAR if available)
    var burstRole: BurstRole?       // selection within a burst
    var place: PlaceRef?            // place, never raw coordinates

    /// Compact JSON used when embedding into asset metadata (EXIF UserComment).
    func metadataJSON() -> String? {
        let encoder = JSONEncoder()
        encoder.outputFormatting = [.sortedKeys, .withoutEscapingSlashes]
        guard let data = try? encoder.encode(self) else { return nil }
        return String(data: data, encoding: .utf8)
    }

    static func decode(fromMetadataJSON json: String) -> CaptureContext? {
        guard let data = json.data(using: .utf8) else { return nil }
        return try? JSONDecoder().decode(CaptureContext.self, from: data)
    }
}

/// Snapshot of the manual settings applied when the photo was taken.
struct ManualSettings: Codable, Sendable, Hashable {
    var iso: Float?                 // nil = auto
    var shutterSeconds: Double?     // nil = auto
    var lensPosition: Float?        // 0...1, nil = autofocus
    var whiteBalanceKelvin: Float?  // nil = auto WB
    var exposureBias: Float
    var lens: LensKind
    var zoomFactor: Double
    var format: CaptureFormat
    /// Optional so recipes saved before this field existed still decode.
    /// nil = auto.
    var flashMode: FlashMode?

    static let automatic = ManualSettings(
        iso: nil, shutterSeconds: nil, lensPosition: nil,
        whiteBalanceKelvin: nil, exposureBias: 0,
        lens: .wide, zoomFactor: 1.0, format: .heic, flashMode: nil
    )
}

enum FlashMode: String, Codable, Sendable, CaseIterable {
    case auto, on, off

    var displayName: String {
        switch self {
        case .auto: "Flash auto"
        case .on: "Flash activé"
        case .off: "Flash désactivé"
        }
    }

    var symbolName: String {
        switch self {
        case .auto: "bolt.badge.a"
        case .on: "bolt.fill"
        case .off: "bolt.slash.fill"
        }
    }

    var next: FlashMode {
        switch self {
        case .auto: .on
        case .on: .off
        case .off: .auto
        }
    }
}

enum LensKind: String, Codable, Sendable, CaseIterable {
    case ultraWide, wide, telephoto

    /// User-facing name, in French (code stays in English).
    var displayName: String {
        switch self {
        case .ultraWide: "Ultra grand-angle"
        case .wide: "Grand-angle"
        case .telephoto: "Téléobjectif"
        }
    }
}

enum CaptureFormat: String, Codable, Sendable, CaseIterable {
    case heic
    case proRAW

    var displayName: String {
        switch self {
        case .heic: "HEIC"
        case .proRAW: "ProRAW"
        }
    }
}

enum BurstRole: String, Codable, Sendable {
    case selected   // user's pick within the burst
    case member
}

/// A place, deliberately coarse. Never raw coordinates (CLAUDE.md §4).
struct PlaceRef: Codable, Sendable {
    var name: String?         // "Chalet", "Garage Marcel"
    var locality: String?     // "Québec"
    var countryCode: String?  // "CA"
}