import Foundation

/// Only read formatting from a selection whose projection has caught up with
/// native text input. While it catches up, the toolbar keeps its last valid state.
struct DocumentToolbarSelection: Equatable {
    var marks: Set<String> = []
    var blocks: Set<String> = []
    var style = "paragraph"
    var font = "sans"
    var size = 12
    var alignment = "left"
    var canUndo = false
    var canRedo = false
    var hasSelection = false

    var styleLabel: String {
        if style.hasPrefix("heading"), let level = Int(style.dropFirst(7)) {
            return String(format: docsMacString("Heading %d"), level)
        }
        return String(localized: "docs.editor.toolbar.block.paragraph", bundle: DocsResources.bundle)
    }
    init() {}

    @MainActor init?(commands: DocumentCommands) {
        guard commands.isEnabled else { return nil }
        marks = Set(["strong", "em", "code"].filter { commands.hasMark($0) })
        blocks = Set(["bullet_list", "ordered_list", "blockquote"].filter { commands.hasBlock($0) })
        if let block = commands.selectedBlock {
            style = block.type == "heading" ? "heading" + (block.attrs?["level"] ?? "1") : "paragraph"
            alignment = block.attrs?["align"] ?? "left"
        }
        font = ["serif", "mono"].first { commands.hasMark("font_" + $0) } ?? "sans"
        size = [8,9,10,11,12,14,18,24,36,48,72].first { commands.hasMark("size_\($0)") } ?? (commands.hasMark("size_sm") ? 10 : commands.hasMark("size_lg") ? 14 : commands.hasMark("size_xl") ? 18 : 12)
        canUndo = commands.model.projection?.canUndo == true
        canRedo = commands.model.projection?.canRedo == true
        hasSelection = commands.model.selection.length > 0
    }
}