//
//  RecipeStore.swift
//  Focale
//
//  Author: Simon-Pierre Boucher
//  Contact: contact@spboucher.ai
//

import Foundation
import Observation

@MainActor
@Observable
final class RecipeStore {
    private(set) var recipes: [Recipe] = []
    var activeRecipeID: Recipe.ID? {
        didSet { save() }
    }

    private let fileURL: URL

    var activeRecipe: Recipe? {
        guard let activeRecipeID else { return nil }
        return recipes.first { $0.id == activeRecipeID }
    }

    init(directory: URL = .applicationSupportDirectory) {
        fileURL = directory.appending(path: "recipes.json")
        load()
        if recipes.isEmpty {
            recipes = Recipe.builtIns
            save()
        }
    }

    func add(_ recipe: Recipe) {
        recipes.append(recipe)
        save()
    }

    func update(_ recipe: Recipe) {
        guard let index = recipes.firstIndex(where: { $0.id == recipe.id }) else { return }
        recipes[index] = recipe
        save()
    }

    func remove(_ id: Recipe.ID) {
        recipes.removeAll { $0.id == id }
        if activeRecipeID == id { activeRecipeID = nil }
        save()
    }

    @discardableResult
    func importRecipe(from data: Data) throws -> Recipe {
        var recipe = try Recipe(importing: data)
        // Re-identify on import so two devices can hold the same shared file.
        recipe = Recipe(
            name: recipe.name,
            settings: recipe.settings,
            autoProjectName: recipe.autoProjectName,
            sceneTrigger: recipe.sceneTrigger,
            showsTimestamp: recipe.showsTimestamp,
            prioritizeOCR: recipe.prioritizeOCR
        )
        add(recipe)
        return recipe
    }

    // MARK: - Persistence

    private struct Snapshot: Codable {
        var recipes: [Recipe]
        var activeRecipeID: Recipe.ID?
    }

    private func load() {
        guard let data = try? Data(contentsOf: fileURL),
              let snapshot = try? JSONDecoder().decode(Snapshot.self, from: data)
        else { return }
        recipes = snapshot.recipes
        activeRecipeID = snapshot.activeRecipeID
    }

    private func save() {
        let snapshot = Snapshot(recipes: recipes, activeRecipeID: activeRecipeID)
        guard let data = try? JSONEncoder().encode(snapshot) else { return }
        try? FileManager.default.createDirectory(
            at: fileURL.deletingLastPathComponent(),
            withIntermediateDirectories: true
        )
        try? data.write(to: fileURL, options: .atomic)
    }
}