//
//  HeaderView.swift
//  oAI
//
//  Slim header — provider, model name, star only.
//  Status pills and stats live in SidebarView and FooterView respectively.
//
// SPDX-License-Identifier: AGPL-3.0-or-later
// Copyright (C) 2026 Rune Olsen
//
// This file is part of oAI.
//
// oAI is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// oAI is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General
// Public License for more details.
//
// You should have received a copy of the GNU Affero General Public
// License along with oAI. If not, see <https://www.gnu.org/licenses/>.


import SwiftUI

struct HeaderView: View {
    let provider: Settings.Provider
    let model: ModelInfo?
    let onModelSelect: () -> Void
    let onProviderChange: (Settings.Provider) -> Void
    var conversationName: String? = nil
    var hasUnsavedChanges: Bool = false
    var onQuickSave: (() -> Void)? = nil
    private let settings = SettingsService.shared
    private let registry = ProviderRegistry.shared

    var body: some View {
        ZStack {
            // Left: provider + model + star
            HStack(spacing: 12) {
                providerMenu
                modelButton
                starButton
                Spacer()
            }

            // Center: conversation title (macOS document-title style)
            conversationTitle
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 8)
        .background(.ultraThinMaterial)
        .overlay(
            Rectangle()
                .fill(Color.oaiBorder.opacity(0.5))
                .frame(height: 1),
            alignment: .bottom
        )
    }

    // MARK: - Conversation title (center)

    @ViewBuilder
    private var conversationTitle: some View {
        if let name = conversationName {
            Button(action: { if hasUnsavedChanges { onQuickSave?() } }) {
                HStack(spacing: 5) {
                    if hasUnsavedChanges {
                        Circle()
                            .fill(Color.orange)
                            .frame(width: 6, height: 6)
                    }
                    Text(name)
                        .font(.system(size: settings.guiTextSize - 1, weight: .medium))
                        .foregroundColor(.oaiPrimary)
                        .lineLimit(1)
                        .frame(maxWidth: 300)
                }
            }
            .buttonStyle(.plain)
            .disabled(!hasUnsavedChanges)
            .help(hasUnsavedChanges ? "Unsaved changes — click to save" : "Saved")
            .animation(.easeInOut(duration: 0.2), value: hasUnsavedChanges)
            .animation(.easeInOut(duration: 0.2), value: name)
        }
    }

    // MARK: - Subviews (extracted so ZStack stays readable)

    private var providerMenu: some View {
        Menu {
            ForEach(registry.configuredProviders, id: \.self) { p in
                Button {
                    onProviderChange(p)
                } label: {
                    HStack {
                        Image(systemName: p.iconName)
                        Text(p.displayName)
                        if p == provider { Image(systemName: "checkmark") }
                    }
                }
            }
        } label: {
            HStack(spacing: 4) {
                Image(systemName: provider.iconName)
                    .font(.system(size: settings.guiTextSize - 2))
                Text(provider.displayName)
                    .font(.system(size: settings.guiTextSize - 2, weight: .medium))
                Image(systemName: "chevron.up.chevron.down")
                    .font(.system(size: 8))
                    .opacity(0.7)
            }
            .foregroundColor(.white)
            .padding(.horizontal, 8)
            .padding(.vertical, 4)
            .background(Color.providerColor(provider))
            .cornerRadius(4)
        }
        .menuStyle(.borderlessButton)
        .fixedSize()
        .help("Switch provider")
    }

    private var modelButton: some View {
        Button(action: onModelSelect) {
            if let model = model {
                HStack(spacing: 6) {
                    Text(model.name)
                        .font(.system(size: settings.guiTextSize, weight: .medium))
                        .foregroundColor(.oaiPrimary)
                    HStack(spacing: 3) {
                        if model.capabilities.vision {
                            Image(systemName: "eye").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                        }
                        if model.capabilities.tools {
                            Image(systemName: "wrench").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                        }
                        if model.capabilities.online {
                            Image(systemName: "globe").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                        }
                        if model.capabilities.imageGeneration {
                            Image(systemName: "paintbrush").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                        }
                    }
                    Image(systemName: "chevron.down").font(.caption2).foregroundColor(.oaiSecondary)
                }
            } else {
                HStack(spacing: 4) {
                    Text("No model selected")
                        .font(.system(size: settings.guiTextSize))
                        .foregroundColor(.oaiSecondary)
                    Image(systemName: "chevron.down").font(.caption2).foregroundColor(.oaiSecondary)
                }
            }
        }
        .buttonStyle(.plain)
        .help("Select model")
    }

    @ViewBuilder
    private var starButton: some View {
        if let model = model {
            let isFav = settings.favoriteModelIds.contains(model.id)
            Button(action: { settings.toggleFavoriteModel(model.id) }) {
                Image(systemName: isFav ? "star.fill" : "star")
                    .font(.system(size: settings.guiTextSize - 3))
                    .foregroundColor(isFav ? .yellow : .oaiSecondary)
            }
            .buttonStyle(.plain)
            .help(isFav ? "Remove from favorites" : "Add to favorites")
        }
    }
}

// MARK: - Status Pills (used by SidebarView)

struct StatusPill: View {
    let icon: String
    let label: LocalizedStringKey
    let color: Color

    var body: some View {
        HStack(spacing: 3) {
            Circle()
                .fill(color)
                .frame(width: 6, height: 6)
            Text(label)
                .font(.system(size: 10, weight: .medium))
                .foregroundColor(.oaiSecondary)
        }
        .padding(.horizontal, 6)
        .padding(.vertical, 2)
        .background(color.opacity(0.1), in: Capsule())
    }
}

struct SyncStatusPill: View {
    private let gitSync = GitSyncService.shared

    private enum SyncPillState { case notConfigured, syncing, error(String), synced(Date?) }
    @State private var syncState: SyncPillState = .notConfigured
    @State private var syncColor: Color = .secondary

    private var syncLabel: LocalizedStringKey {
        switch syncState {
        case .notConfigured:  return "Sync"
        case .syncing:        return "Syncing"
        case .error:          return "Error"
        case .synced:         return "Synced"
        }
    }

    private var tooltipText: LocalizedStringKey {
        switch syncState {
        case .notConfigured:       return "Sync not configured"
        case .syncing:             return "Syncing..."
        case .error(let msg):      return "Sync failed: \(msg)"
        case .synced(let date):
            guard let date else { return "Synced" }
            let rel = RelativeDateTimeFormatter().localizedString(for: date, relativeTo: .now)
            return "Last synced: \(rel)"
        }
    }

    var body: some View {
        HStack(spacing: 3) {
            Circle()
                .fill(syncColor)
                .frame(width: 6, height: 6)
            Text(syncLabel)
                .font(.system(size: 10, weight: .medium))
                .foregroundColor(.oaiSecondary)
        }
        .padding(.horizontal, 6)
        .padding(.vertical, 2)
        .background(syncColor.opacity(0.1), in: Capsule())
        .help(tooltipText)
        .onAppear { updateState() }
        .onChange(of: gitSync.syncStatus)     { updateState() }
        .onChange(of: gitSync.isSyncing)      { updateState() }
        .onChange(of: gitSync.lastSyncError)  { updateState() }
    }

    private func updateState() {
        if let error = gitSync.lastSyncError {
            syncState = .error(error); syncColor = .red
        } else if gitSync.isSyncing {
            syncState = .syncing;      syncColor = .orange
        } else if gitSync.syncStatus.isCloned {
            syncState = .synced(gitSync.syncStatus.lastSyncTime); syncColor = .green
        } else {
            syncState = .notConfigured; syncColor = .secondary
        }
    }
}

#Preview {
    VStack {
        HeaderView(
            provider: .openrouter,
            model: ModelInfo.mockModels.first,
            onModelSelect: {},
            onProviderChange: { _ in }
        )
        Spacer()
    }
    .background(Color.oaiBackground)
}