//
//  MessageRow.swift
//  Zyquo Local
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//

import SwiftUI

/// One transcript message: bubble, hover timestamp + actions, thinking
/// disclosure and the stats caption line for assistant messages.
struct MessageRow: View {
    let message: Message
    let conversation: Conversation
    @Environment(AppModel.self) private var app
    @State private var hovering = false
    @State private var editing = false
    @State private var editText = ""

    var body: some View {
        HStack(alignment: .top, spacing: 0) {
            if message.role == .user { Spacer(minLength: ZyquoTheme.Spacing.xxl) }

            VStack(alignment: message.role == .user ? .trailing : .leading, spacing: ZyquoTheme.Spacing.xxs) {
                bubble
                captionLine
            }
            .frame(
                maxWidth: ZyquoTheme.messageColumnMaxWidth * 0.86,
                alignment: message.role == .user ? .trailing : .leading
            )

            if message.role == .assistant { Spacer(minLength: ZyquoTheme.Spacing.xxl) }
        }
        .onHover { hovering = $0 }
        .transition(.opacity.combined(with: .offset(y: 6)))
    }

    @ViewBuilder
    private var bubble: some View {
        VStack(alignment: .leading, spacing: ZyquoTheme.Spacing.xs) {
            if let thinking = message.thinking, !thinking.isEmpty {
                ThinkingDisclosure(thinking: thinking, isLive: false)
            }
            if editing {
                editor
            } else {
                MarkdownText(message.content)
                    .textSelection(.enabled)
            }
        }
        .padding(ZyquoTheme.Spacing.s)
        .background(bubbleBackground, in: RoundedRectangle(cornerRadius: ZyquoTheme.Radius.m))
        .overlay(
            RoundedRectangle(cornerRadius: ZyquoTheme.Radius.m)
                .stroke(message.role == .assistant ? ZyquoTheme.border : .clear, lineWidth: ZyquoTheme.hairline)
        )
        .contextMenu { actions }
    }

    private var bubbleBackground: Color {
        message.role == .user ? ZyquoTheme.accentSubtle : ZyquoTheme.surface
    }

    private var editor: some View {
        VStack(alignment: .trailing, spacing: ZyquoTheme.Spacing.xs) {
            TextEditor(text: $editText)
                .font(ZyquoTheme.chatBody)
                .frame(minHeight: 60, maxHeight: 160)
                .scrollContentBackground(.hidden)
            HStack {
                Button("Cancel") { editing = false }
                    .buttonStyle(.bordered)
                Button("Resend") {
                    editing = false
                    app.chat.editAndResend(messageID: message.id, newText: editText, in: conversation)
                }
                .buttonStyle(.borderedProminent)
                .tint(ZyquoTheme.accent)
                .disabled(editText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
            }
        }
        .frame(width: 420)
    }

    @ViewBuilder
    private var actions: some View {
        Button("Copy") {
            NSPasteboard.general.clearContents()
            NSPasteboard.general.setString(message.content, forType: .string)
        }
        if message.role == .user {
            Button("Edit & Resend") {
                editText = message.content
                editing = true
            }
        }
        if message.role == .assistant {
            Button("Regenerate") {
                app.chat.regenerate(in: conversation)
            }
            .disabled(app.chat.isGenerating)
        }
        Button("Quote Reply") {
            let quoted = message.content
                .split(separator: "\n", omittingEmptySubsequences: false)
                .map { "> \($0)" }
                .joined(separator: "\n")
            NotificationCenter.default.post(name: .zyquoQuoteReply, object: quoted + "\n\n")
        }
        Divider()
        Button("Delete", role: .destructive) {
            var c = conversation
            c.messages.removeAll { $0.id == message.id }
            app.update(c, touch: false)
        }
    }

    @ViewBuilder
    private var captionLine: some View {
        HStack(spacing: ZyquoTheme.Spacing.xs) {
            if message.role == .assistant, let stats = message.stats {
                Text(String(
                    format: "⚡ %.1f tok/s · %d tokens · %.1fs to first token",
                    stats.tokensPerSecond, stats.generationTokenCount, stats.timeToFirstToken
                ))
                .font(ZyquoTheme.caption)
                .foregroundStyle(ZyquoTheme.textTertiary)
            }
            if hovering {
                Text(message.date, format: .dateTime.hour().minute())
                    .font(ZyquoTheme.caption)
                    .foregroundStyle(ZyquoTheme.textTertiary)
                    .transition(.opacity)
            }
        }
        .animation(.easeOut(duration: 0.08), value: hovering)
    }
}

/// Collapsible "Thinking…" section for reasoning models.
struct ThinkingDisclosure: View {
    let thinking: String
    let isLive: Bool
    @State private var expanded = false

    var body: some View {
        VStack(alignment: .leading, spacing: ZyquoTheme.Spacing.xxs) {
            Button {
                withAnimation(.snappy(duration: 0.2)) { expanded.toggle() }
            } label: {
                HStack(spacing: ZyquoTheme.Spacing.xxs) {
                    Image(systemName: "brain")
                        .font(.system(size: 10))
                    Text(isLive ? "Thinking…" : "Thought process")
                        .font(ZyquoTheme.caption.weight(.medium))
                    Image(systemName: "chevron.right")
                        .font(.system(size: 8, weight: .semibold))
                        .rotationEffect(.degrees(expanded ? 90 : 0))
                }
                .foregroundStyle(ZyquoTheme.textSecondary)
            }
            .buttonStyle(.plain)

            if expanded || isLive {
                Text(thinking)
                    .font(ZyquoTheme.caption)
                    .foregroundStyle(ZyquoTheme.textSecondary)
                    .lineSpacing(3)
                    .textSelection(.enabled)
                    .padding(ZyquoTheme.Spacing.xs)
                    .frame(maxWidth: .infinity, alignment: .leading)
                    .background(ZyquoTheme.surfaceSecondary, in: RoundedRectangle(cornerRadius: ZyquoTheme.Radius.s))
                    .frame(maxHeight: isLive && !expanded ? 96 : .infinity)
                    .clipped()
            }
        }
    }
}

extension Notification.Name {
    static let zyquoQuoteReply = Notification.Name("zyquoQuoteReply")
}