//
//  HistoryView.swift
//  Zyquo Atlas
//
//  Author: Simon-Pierre Boucher
//  Mail: contact@spboucher.ai
//
//  Full-text history (⌘Y): grouped by day, searchable, with delete controls and
//  "ask AI about my history" — the model receives only titles/hosts (never page
//  content), on explicit user action, via the shared provider layer.
//

import SwiftUI

struct HistoryView: View {
    let onOpen: (String) -> Void
    @EnvironmentObject private var env: AppEnvironment
    @EnvironmentObject private var themeEngine: ThemeEngine
    @Environment(\.dismiss) private var dismiss
    private var theme: AtlasTheme { themeEngine.theme }

    @State private var query = ""
    @State private var askText = ""
    @StateObject private var ai = AIService()

    var body: some View {
        VStack(spacing: 0) {
            header
            Divider().overlay(theme.border)
            askBar
            Divider().overlay(theme.border)
            list
        }
        .frame(width: 660, height: 620)
        .background(theme.backgroundColor)
    }

    private var header: some View {
        HStack {
            Label("History", systemImage: "clock").font(ZyquoFont.title).foregroundStyle(theme.textPrimary)
            Spacer()
            searchField
            Menu {
                Button("Clear last hour") { env.history.deleteRange(since: Date().addingTimeInterval(-3600)) }
                Button("Clear today") { env.history.deleteRange(since: Calendar.current.startOfDay(for: Date())) }
                Button("Clear all", role: .destructive) { env.history.clearAll() }
            } label: { Image(systemName: "trash") }
                .menuStyle(.borderlessButton).frame(width: 44).foregroundStyle(theme.textSecondary)
            Button("Done") { dismiss() }.foregroundStyle(theme.accent)
        }
        .padding(ZyquoSpacing.md)
        .background(theme.surface)
    }

    private var searchField: some View {
        HStack(spacing: ZyquoSpacing.xs) {
            Image(systemName: "magnifyingglass").font(.system(size: 11)).foregroundStyle(theme.textTertiary)
            TextField("Search history", text: $query).textFieldStyle(.plain).font(ZyquoFont.control)
                .foregroundStyle(theme.textPrimary).frame(width: 180)
        }
        .padding(.horizontal, ZyquoSpacing.sm).frame(height: 28)
        .background(RoundedRectangle(cornerRadius: ZyquoRadius.small).fill(theme.surfaceSecondary))
    }

    private var askBar: some View {
        VStack(alignment: .leading, spacing: ZyquoSpacing.xs) {
            HStack(spacing: ZyquoSpacing.xs) {
                Image(systemName: "sparkles").foregroundStyle(theme.accentIndigo)
                TextField("Ask AI about your history (e.g. “that article about maps I read last week”)", text: $askText)
                    .textFieldStyle(.plain).font(ZyquoFont.body())
                    .foregroundStyle(theme.textPrimary)
                    .onSubmit(runAsk)
                if ai.isStreaming { Button("Stop") { ai.cancel() }.font(ZyquoFont.caption).foregroundStyle(theme.danger) }
                else { Button("Ask", action: runAsk).font(ZyquoFont.caption).foregroundStyle(theme.accent) }
            }
            if !ai.output.isEmpty || ai.errorText != nil {
                ScrollView {
                    Text(ai.errorText ?? ai.output)
                        .font(ZyquoFont.body()).foregroundStyle(ai.errorText != nil ? theme.danger : theme.textPrimary)
                        .frame(maxWidth: .infinity, alignment: .leading).textSelection(.enabled)
                }
                .frame(maxHeight: 120)
            }
        }
        .padding(ZyquoSpacing.md)
    }

    private var list: some View {
        ScrollView {
            LazyVStack(alignment: .leading, spacing: 0, pinnedViews: [.sectionHeaders]) {
                ForEach(env.history.grouped(query), id: \.day) { group in
                    Section {
                        ForEach(group.items) { entry in
                            row(entry)
                            Divider().overlay(theme.border)
                        }
                    } header: {
                        Text(dayLabel(group.day)).font(ZyquoFont.caption).foregroundStyle(theme.textTertiary)
                            .frame(maxWidth: .infinity, alignment: .leading)
                            .padding(.horizontal, ZyquoSpacing.md).padding(.vertical, ZyquoSpacing.xs)
                            .background(theme.backgroundColor)
                    }
                }
                if env.history.entries.isEmpty {
                    Text("No history yet").font(ZyquoFont.caption).foregroundStyle(theme.textTertiary)
                        .frame(maxWidth: .infinity).padding(ZyquoSpacing.xxl)
                }
            }
        }
    }

    private func row(_ entry: HistoryEntry) -> some View {
        HStack(spacing: ZyquoSpacing.sm) {
            Image(systemName: "globe").font(.system(size: 11)).foregroundStyle(theme.textTertiary)
            VStack(alignment: .leading, spacing: 1) {
                Text(entry.title).font(ZyquoFont.body(size: 12.5)).lineLimit(1).foregroundStyle(theme.textPrimary)
                Text(entry.host).font(ZyquoFont.caption).lineLimit(1).foregroundStyle(theme.textTertiary)
            }
            Spacer()
            Text(HistoryService.relative(entry.lastVisit)).font(ZyquoFont.caption).foregroundStyle(theme.textTertiary)
            Button { env.history.delete(entry.id) } label: { Image(systemName: "xmark") }
                .buttonStyle(.plain).foregroundStyle(theme.textTertiary)
        }
        .padding(.horizontal, ZyquoSpacing.md).padding(.vertical, ZyquoSpacing.xs)
        .contentShape(Rectangle())
        .onTapGesture { onOpen(entry.url); dismiss() }
    }

    private func runAsk() {
        let q = askText.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !q.isEmpty, let model = env.model(for: .standard) else { return }
        guard let key = try? env.vault.apiKey(for: model.provider) else {
            askText = ""; return
        }
        let context = env.history.aiContext()
        let prompt = """
        Here is a list of the user's recent browsing history (title — site — when). \
        Answer the user's question by pointing to the most relevant items. If none \
        match, say so. Do not invent entries.

        QUESTION: \(q)

        HISTORY:
        \(context)
        """
        ai.runRawPrompt(system: "You help the user find pages in their browsing history.",
                        userText: prompt, model: model, apiKey: key)
    }

    private func dayLabel(_ day: Date) -> String {
        let cal = Calendar.current
        if cal.isDateInToday(day) { return "Today" }
        if cal.isDateInYesterday(day) { return "Yesterday" }
        let f = DateFormatter(); f.dateStyle = .medium
        return f.string(from: day)
    }
}