//
//  CommandPalette.swift
//  Zyquo Router
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//
//  ⌘K: fuzzy access to everything — start/stop, sections, copy endpoint,
//  and copy any model ID. Return runs the highlighted action.
//

import SwiftUI

struct CommandPalette: View {
    @Binding var isPresented: Bool
    @EnvironmentObject private var server: ServerController
    @EnvironmentObject private var catalog: ModelCatalog

    @State private var query = ""
    @State private var highlighted = 0
    @FocusState private var fieldFocused: Bool

    private struct Action: Identifiable {
        let id: String
        let title: String
        let subtitle: String?
        let systemImage: String
        let run: () -> Void
    }

    private var actions: [Action] {
        var all: [Action] = [
            Action(
                id: "server",
                title: server.isRunning ? "Stop Server" : "Start Server",
                subtitle: server.isRunning ? "Port \(server.port)" : nil,
                systemImage: "power",
                run: { server.toggle() }
            ),
            Action(
                id: "copy-endpoint",
                title: "Copy Endpoint URL",
                subtitle: server.endpointURL,
                systemImage: "doc.on.doc",
                run: {
                    NSPasteboard.general.clearContents()
                    NSPasteboard.general.setString(server.endpointURL, forType: .string)
                }
            ),
        ]
        for section in AppSection.allCases {
            all.append(Action(
                id: "go-\(section.rawValue)",
                title: "Go to \(section.rawValue)",
                subtitle: nil,
                systemImage: section.systemImage,
                run: { UserDefaults.standard.set(section.rawValue, forKey: "selectedSection") }
            ))
        }
        for model in catalog.all {
            let id = RequestRouter.namespacedID(for: model)
            all.append(Action(
                id: "model-\(id)",
                title: id,
                subtitle: "Copy model ID",
                systemImage: "square.grid.2x2",
                run: {
                    NSPasteboard.general.clearContents()
                    NSPasteboard.general.setString(id, forType: .string)
                }
            ))
        }
        return all
    }

    private var filtered: [Action] {
        let trimmed = query.trimmingCharacters(in: .whitespaces)
        guard !trimmed.isEmpty else {
            return Array(actions.prefix(9))
        }
        return Array(actions.filter {
            $0.title.localizedCaseInsensitiveContains(trimmed)
        }.prefix(9))
    }

    var body: some View {
        VStack(spacing: 0) {
            TextField("Type a command or model…", text: $query)
                .textFieldStyle(.plain)
                .font(ZyquoFont.body(size: 15))
                .padding(ZyquoSpacing.md)
                .focused($fieldFocused)
                .onSubmit { runHighlighted() }
                .onChange(of: query) { _ in highlighted = 0 }

            ZyquoHairline()

            VStack(spacing: 0) {
                ForEach(Array(filtered.enumerated()), id: \.element.id) { index, action in
                    HStack(spacing: ZyquoSpacing.sm) {
                        Image(systemName: action.systemImage)
                            .font(.system(size: 12))
                            .foregroundStyle(index == highlighted ? ZyquoColor.accent : ZyquoColor.textSecondary)
                            .frame(width: 18)
                        Text(action.title)
                            .font(action.id.hasPrefix("model-") ? ZyquoFont.mono(size: 12.5) : ZyquoFont.body())
                            .foregroundStyle(ZyquoColor.textPrimary)
                            .lineLimit(1)
                            .truncationMode(.middle)
                        Spacer()
                        if let subtitle = action.subtitle {
                            Text(subtitle)
                                .font(ZyquoFont.caption)
                                .foregroundStyle(ZyquoColor.textTertiary)
                                .lineLimit(1)
                        }
                    }
                    .padding(.horizontal, ZyquoSpacing.md)
                    .padding(.vertical, ZyquoSpacing.xs)
                    .background(index == highlighted ? ZyquoColor.accentSubtle : .clear)
                    .contentShape(Rectangle())
                    .onTapGesture {
                        action.run()
                        isPresented = false
                    }
                    .onHover { hover in
                        if hover { highlighted = index }
                    }
                }
            }
            .padding(.vertical, ZyquoSpacing.xxs)
        }
        .frame(width: 520)
        .background(
            RoundedRectangle(cornerRadius: ZyquoRadius.large, style: .continuous)
                .fill(ZyquoColor.surface)
                .overlay(
                    RoundedRectangle(cornerRadius: ZyquoRadius.large, style: .continuous)
                        .strokeBorder(ZyquoColor.border, lineWidth: ZyquoMetrics.hairline)
                )
        )
        .zyquoSoftShadow()
        .onAppear { fieldFocused = true }
        .background(paletteKeyHandlers)
    }

    /// Hidden buttons carrying the arrow-key/escape shortcuts.
    private var paletteKeyHandlers: some View {
        Group {
            Button("") { highlighted = min(highlighted + 1, filtered.count - 1) }
                .keyboardShortcut(.downArrow, modifiers: [])
            Button("") { highlighted = max(highlighted - 1, 0) }
                .keyboardShortcut(.upArrow, modifiers: [])
            Button("") { isPresented = false }
                .keyboardShortcut(.escape, modifiers: [])
        }
        .hidden()
    }

    private func runHighlighted() {
        guard filtered.indices.contains(highlighted) else { return }
        filtered[highlighted].run()
        isPresented = false
    }
}