//
//  InputBarView.swift
//  Zyquo Cloud
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//
//  Floating input card docked at the bottom: auto-growing multiline editor,
//  attach button, parameter quick-toggle, circular send button (⌘↩),
//  attachment thumbnails, drag-and-drop with dashed accent highlight.
//

import SwiftUI
import UniformTypeIdentifiers

struct InputBarView: View {
    @Binding var text: String
    @Binding var attachments: [Attachment]
    let isStreaming: Bool
    let supportsVision: Bool
    var onSend: () -> Void
    var onStop: () -> Void
    var parametersContent: () -> AnyView

    @State private var dropTargeted = false
    @State private var showingParameters = false
    @EnvironmentObject private var appearance: AppearanceStore
    @FocusState private var editorFocused: Bool

    private var canSend: Bool {
        !text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty || !attachments.isEmpty
    }

    var body: some View {
        VStack(spacing: ZyquoSpacing.xs) {
            if !attachments.isEmpty {
                attachmentStrip
            }
            HStack(alignment: .bottom, spacing: ZyquoSpacing.xs) {
                attachButton
                editor
                parameterToggle
                sendButton
            }
        }
        .padding(ZyquoSpacing.sm)
        .background(
            RoundedRectangle(cornerRadius: ZyquoRadius.large, style: .continuous)
                .fill(ZyquoColor.surface)
                .overlay(
                    RoundedRectangle(cornerRadius: ZyquoRadius.large, style: .continuous)
                        .strokeBorder(
                            dropTargeted ? ZyquoColor.accent : ZyquoColor.border,
                            style: StrokeStyle(
                                lineWidth: dropTargeted ? 1.5 : ZyquoMetrics.hairline,
                                dash: dropTargeted ? [6, 4] : []
                            )
                        )
                )
        )
        .zyquoSoftShadow()
        .padding(.horizontal, ZyquoSpacing.sm)
        .padding(.bottom, ZyquoSpacing.sm)
        .onDrop(of: [.fileURL, .image], isTargeted: $dropTargeted) { providers in
            handleDrop(providers)
        }
    }

    // MARK: - Pieces

    private var editor: some View {
        ZStack(alignment: .topLeading) {
            if text.isEmpty {
                Text("Message…")
                    .font(ZyquoFont.body(size: appearance.chatFontSize))
                    .foregroundStyle(ZyquoColor.textTertiary)
                    .padding(.top, 2)
                    .allowsHitTesting(false)
            }
            TextEditor(text: $text)
                .font(ZyquoFont.body(size: appearance.chatFontSize))
                .foregroundStyle(ZyquoColor.textPrimary)
                .scrollContentBackground(.hidden)
                .frame(minHeight: 22, maxHeight: 200)
                .fixedSize(horizontal: false, vertical: text.count < 2000)
                .focused($editorFocused)
                .onAppear { editorFocused = true }
        }
    }

    private var attachButton: some View {
        Button {
            presentFilePicker()
        } label: {
            Image(systemName: "paperclip")
                .font(.system(size: 14))
                .foregroundStyle(ZyquoColor.textSecondary)
                .frame(width: 26, height: 26)
        }
        .buttonStyle(.plain)
        .zyquoHoverHighlight()
        .help(supportsVision ? "Attach images or text files" : "Attach text files")
    }

    private var parameterToggle: some View {
        Button {
            showingParameters.toggle()
        } label: {
            Image(systemName: "slider.horizontal.3")
                .font(.system(size: 13))
                .foregroundStyle(ZyquoColor.textSecondary)
                .frame(width: 26, height: 26)
        }
        .buttonStyle(.plain)
        .zyquoHoverHighlight()
        .help("Generation parameters")
        .popover(isPresented: $showingParameters, arrowEdge: .top) {
            parametersContent()
        }
    }

    private var sendButton: some View {
        Button {
            isStreaming ? onStop() : (canSend ? onSend() : ())
        } label: {
            Image(systemName: isStreaming ? "stop.fill" : "arrow.up")
                .font(.system(size: 13, weight: .semibold))
                .foregroundStyle(.white)
                .frame(width: 28, height: 28)
                .background(
                    Circle().fill(
                        isStreaming
                            ? ZyquoColor.danger
                            : (canSend ? ZyquoColor.accent : ZyquoColor.textTertiary)
                    )
                )
        }
        .buttonStyle(PressableButtonStyle())
        .keyboardShortcut(.return, modifiers: .command)
        .help(isStreaming ? "Stop generating" : "Send (⌘↩)")
    }

    private var attachmentStrip: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: ZyquoSpacing.xs) {
                ForEach(attachments) { attachment in
                    AttachmentThumbnail(attachment: attachment) {
                        attachments.removeAll { $0.id == attachment.id }
                    }
                }
            }
        }
        .frame(height: ZyquoMetrics.attachmentThumbnail + 8)
    }

    // MARK: - Attachment intake

    private static let textExtensions: Set<String> = [
        "txt", "md", "markdown", "csv", "json", "yaml", "yml", "xml", "log",
        "swift", "py", "js", "ts", "jsx", "tsx", "html", "css", "sh", "zsh",
        "bash", "sql", "go", "rs", "c", "h", "cpp", "hpp", "m", "mm", "java",
        "rb", "php", "toml", "ini", "cfg", "tex",
    ]
    private static let imageExtensions: Set<String> = ["png", "jpg", "jpeg", "webp", "gif"]

    private func presentFilePicker() {
        let panel = NSOpenPanel()
        panel.allowsMultipleSelection = true
        panel.canChooseDirectories = false
        panel.begin { response in
            guard response == .OK else { return }
            for url in panel.urls { ingest(url: url) }
        }
    }

    private func handleDrop(_ providers: [NSItemProvider]) -> Bool {
        var handled = false
        for provider in providers where provider.hasItemConformingToTypeIdentifier(UTType.fileURL.identifier) {
            handled = true
            provider.loadItem(forTypeIdentifier: UTType.fileURL.identifier) { item, _ in
                guard let data = item as? Data,
                      let url = URL(dataRepresentation: data, relativeTo: nil) else { return }
                DispatchQueue.main.async { ingest(url: url) }
            }
        }
        return handled
    }

    private func ingest(url: URL) {
        let ext = url.pathExtension.lowercased()
        guard let data = try? Data(contentsOf: url) else { return }
        if Self.imageExtensions.contains(ext) {
            let mime = ext == "jpg" ? "image/jpeg" : "image/\(ext)"
            attachments.append(
                Attachment(kind: .image, fileName: url.lastPathComponent, data: data, mimeType: mime)
            )
        } else if Self.textExtensions.contains(ext) || (String(data: data, encoding: .utf8) != nil && data.count < 512_000) {
            attachments.append(
                Attachment(kind: .textFile, fileName: url.lastPathComponent, data: data, mimeType: "text/plain")
            )
        }
    }
}

/// 56pt thumbnail with a remove button; images preview, text files show an icon.
private struct AttachmentThumbnail: View {
    let attachment: Attachment
    var onRemove: () -> Void

    var body: some View {
        ZStack(alignment: .topTrailing) {
            Group {
                if attachment.kind == .image, let image = NSImage(data: attachment.data) {
                    Image(nsImage: image)
                        .resizable()
                        .aspectRatio(contentMode: .fill)
                } else {
                    VStack(spacing: 2) {
                        Image(systemName: "doc.text")
                            .font(.system(size: 16))
                            .foregroundStyle(ZyquoColor.textSecondary)
                        Text(attachment.fileName)
                            .font(.system(size: 8))
                            .foregroundStyle(ZyquoColor.textTertiary)
                            .lineLimit(1)
                    }
                    .padding(4)
                }
            }
            .frame(width: ZyquoMetrics.attachmentThumbnail, height: ZyquoMetrics.attachmentThumbnail)
            .background(ZyquoColor.surfaceSecondary)
            .clipShape(RoundedRectangle(cornerRadius: ZyquoRadius.small, style: .continuous))

            Button(action: onRemove) {
                Image(systemName: "xmark.circle.fill")
                    .font(.system(size: 12))
                    .foregroundStyle(ZyquoColor.textSecondary)
                    .background(Circle().fill(ZyquoColor.surface))
            }
            .buttonStyle(.plain)
            .offset(x: 5, y: -5)
        }
        .padding(.top, 4)
    }
}