//
//  StartPageView.swift
//  Zyquo Atlas
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//
//  The customizable new-tab / start page (Phase 4.2). Shows the theme
//  background, a greeting, a prominent AI-or-search ask box, and a favorites
//  quick grid. Bookmarks/history widgets and per-user layout of these sections
//  fill in with the bookmark & history services in Phase 6.
//

import SwiftUI

struct StartPageView: View {
    let onNavigate: (String) -> Void
    let onAsk: () -> Void
    @EnvironmentObject private var themeEngine: ThemeEngine
    private var theme: AtlasTheme { themeEngine.theme }

    @State private var query = ""

    // Placeholder favorites until BookmarksService (Phase 6).
    private let quickLinks: [(String, String)] = [
        ("Wikipedia", "https://en.wikipedia.org"),
        ("DuckDuckGo", "https://duckduckgo.com"),
        ("GitHub", "https://github.com"),
        ("Hacker News", "https://news.ycombinator.com"),
        ("MDN", "https://developer.mozilla.org"),
        ("arXiv", "https://arxiv.org"),
    ]

    var body: some View {
        ZStack {
            theme.backgroundView.ignoresSafeArea()

            VStack(spacing: ZyquoSpacing.xl) {
                Spacer()

                VStack(spacing: ZyquoSpacing.xs) {
                    Text("Zyquo Atlas")
                        .font(themeEngine.layout.font(34, weight: .bold))
                        .foregroundStyle(theme.textPrimary)
                    Text("Explore the web, with AI everywhere.")
                        .font(themeEngine.layout.font(14))
                        .foregroundStyle(theme.textSecondary)
                }

                askBox
                    .frame(maxWidth: 620)

                favoritesGrid
                    .frame(maxWidth: 620)

                Spacer()
                Spacer()
            }
            .padding(ZyquoSpacing.xxl)
        }
    }

    private var askBox: some View {
        HStack(spacing: ZyquoSpacing.sm) {
            Image(systemName: "magnifyingglass")
                .foregroundStyle(theme.textTertiary)
            TextField("Search, enter a URL, or ask AI…", text: $query)
                .textFieldStyle(.plain)
                .font(themeEngine.layout.font(15))
                .foregroundStyle(theme.textPrimary)
                .onSubmit {
                    let q = query.trimmingCharacters(in: .whitespacesAndNewlines)
                    guard !q.isEmpty else { return }
                    onNavigate(q); query = ""
                }
            Button(action: onAsk) {
                Label("Ask AI", systemImage: "sparkles")
                    .font(themeEngine.layout.font(12, weight: .medium))
                    .padding(.horizontal, ZyquoSpacing.sm)
                    .padding(.vertical, ZyquoSpacing.xxs)
                    .background(RoundedRectangle(cornerRadius: ZyquoRadius.small).fill(theme.accentSubtle))
                    .foregroundStyle(theme.accentIndigo)
            }
            .buttonStyle(.plain)
        }
        .padding(.horizontal, ZyquoSpacing.md)
        .frame(height: 52)
        .background(
            RoundedRectangle(cornerRadius: ZyquoRadius.large)
                .fill(theme.surface)
                .shadow(color: ZyquoShadow.soft.color, radius: ZyquoShadow.soft.radius,
                        y: ZyquoShadow.soft.y)
        )
        .overlay(
            RoundedRectangle(cornerRadius: ZyquoRadius.large)
                .strokeBorder(theme.border, lineWidth: ZyquoMetrics.hairline)
        )
    }

    private var favoritesGrid: some View {
        LazyVGrid(columns: Array(repeating: GridItem(.flexible(), spacing: ZyquoSpacing.sm), count: 3),
                  spacing: ZyquoSpacing.sm) {
            ForEach(quickLinks, id: \.0) { name, url in
                Button { onNavigate(url) } label: {
                    HStack(spacing: ZyquoSpacing.xs) {
                        Image(systemName: "globe").foregroundStyle(theme.accent)
                        Text(name)
                            .font(themeEngine.layout.font(12.5, weight: .medium))
                            .foregroundStyle(theme.textPrimary)
                            .lineLimit(1)
                        Spacer(minLength: 0)
                    }
                    .padding(.horizontal, ZyquoSpacing.sm)
                    .frame(height: 40)
                    .background(RoundedRectangle(cornerRadius: ZyquoRadius.medium).fill(theme.surface))
                    .overlay(RoundedRectangle(cornerRadius: ZyquoRadius.medium)
                        .strokeBorder(theme.border, lineWidth: ZyquoMetrics.hairline))
                }
                .buttonStyle(.plain)
            }
        }
    }
}