//
//  SharedInbox.swift
//  Poche
//
//  Author:  Simon-Pierre Boucher
//  Contact: contact@spboucher.ai
//
//  Compiled into BOTH the app and the Share Extension: the extension
//  appends, the app drains. Everything stays inside the app group —
//  shared content never touches the network (CLAUDE.md §7).
//

import Foundation

struct SharedInboxItem: Codable, Sendable {
    let title: String
    let content: String
    let date: Date
}

enum SharedInbox {
    static let groupID = "group.ai.spboucher.poche"

    static var url: URL? {
        FileManager.default
            .containerURL(forSecurityApplicationGroupIdentifier: groupID)?
            .appendingPathComponent("inbox.json")
    }

    static func append(_ item: SharedInboxItem, at url: URL? = SharedInbox.url) {
        guard let url else { return }
        var items = read(at: url)
        items.append(item)
        let encoder = JSONEncoder()
        encoder.dateEncodingStrategy = .iso8601
        if let data = try? encoder.encode(items) {
            try? data.write(to: url, options: .atomic)
        }
    }

    /// Returns all pending items and empties the inbox.
    static func drain(at url: URL? = SharedInbox.url) -> [SharedInboxItem] {
        guard let url else { return [] }
        let items = read(at: url)
        if !items.isEmpty {
            try? FileManager.default.removeItem(at: url)
        }
        return items
    }

    private static func read(at url: URL) -> [SharedInboxItem] {
        guard let data = try? Data(contentsOf: url) else { return [] }
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        return (try? decoder.decode([SharedInboxItem].self, from: data)) ?? []
    }
}