import SwiftUI

struct EditorTabBar: View {
    @ObservedObject var editorState: EditorState

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 0) {
                ForEach(editorState.tabs) { tab in
                    EditorTabCell(
                        tab: tab,
                        isActive: tab.id == editorState.activeTabId,
                        onSelect: { editorState.activeTabId = tab.id },
                        onClose:  { editorState.closeTab(id: tab.id) }
                    )
                }
            }
        }
        .frame(height: 36)
        .background(Color(.secondarySystemBackground))
        .overlay(alignment: .bottom) { Divider() }
    }
}

struct EditorTabCell: View {
    let tab:      EditorTab
    let isActive: Bool
    let onSelect: () -> Void
    let onClose:  () -> Void
    @State private var isHovered = false

    var body: some View {
        HStack(spacing: 6) {
            if tab.isDirty {
                Circle().fill(Color.accentColor).frame(width: 6, height: 6)
            } else {
                Button(action: onClose) {
                    Image(systemName: "xmark").font(.system(size: 9, weight: .semibold))
                        .frame(width: 14, height: 14).contentShape(Circle())
                }
                .buttonStyle(.plain)
                .opacity((isActive || isHovered) ? 1 : 0)
            }
            Image(systemName: fileIcon(for: tab.fileName))
                .font(.system(size: 11)).foregroundStyle(iconColor(for: tab.fileName))
            Text(tab.fileName)
                .font(.system(.caption, design: .monospaced)).lineLimit(1)
        }
        .padding(.horizontal, 10).frame(height: 36)
        .background(isActive ? Color(.systemBackground) : .clear)
        .overlay(alignment: .bottom) {
            if isActive { Rectangle().fill(Color.accentColor).frame(height: 2) }
        }
        .contentShape(Rectangle())
        .onTapGesture(perform: onSelect)
        .onHover { isHovered = $0 }
    }

    private func fileIcon(for name: String) -> String {
        switch (name as NSString).pathExtension.lowercased() {
        case "swift": return "swift"; case "json": return "curlybraces"
        case "md": return "doc.text"; case "sh": return "terminal"; default: return "doc"
        }
    }
    private func iconColor(for name: String) -> Color {
        switch (name as NSString).pathExtension.lowercased() {
        case "swift": return .orange; case "json": return .yellow
        case "md": return .blue; default: return .secondary
        }
    }
}