import AppKit
import SstCore
import SstData
import SstUI
import SwiftUI

private let dutch = Locale(identifier: "nl_NL")

struct HistoryView: View {
    @EnvironmentObject private var model: AppModel
    @ObservedObject var list: HistoryViewModel
    @FocusState private var searchFocused: Bool
    @FocusState private var listFocused: Bool

    var body: some View {
        VStack(spacing: Layout.panelGap) {
            SearchField(text: $list.query, focused: $searchFocused)
            ZStack {
                PaperBackground()
                content
            }
        }
        .onChange(of: model.searchFocusTick) { _, _ in searchFocused = true }
    }

    @ViewBuilder
    private var content: some View {
        if list.days.isEmpty {
            Text(emptyMessage)
                .textStyle(Typography.body)
                .foregroundStyle(Palette.inkSecondary)
                .padding(Layout.panelPadding)
                .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .topLeading)
        } else {
            ScrollList {
                ForEach(list.days) { day in
                    Section {
                        ForEach(day.entries) { entry in
                            HistoryRow(entry: entry, isSelected: list.selection == entry.id, list: list)
                        }
                    } header: {
                        SilkLabel(day.day.formatted(Date.FormatStyle(date: .complete, time: .omitted).locale(dutch)))
                            .padding(.horizontal, Space.s4)
                            .padding(.vertical, Space.s3)
                            .frame(maxWidth: .infinity, alignment: .leading)
                            .background(Palette.surfacePaper)
                    }
                }
            }
            .focusable()
            .focused($listFocused)
            .focusEffectDisabled()
            .onChange(of: list.selection) { _, new in if new != nil { listFocused = true } }
            .onDeleteCommand {
                if let id = list.selection { list.delete(id: id) }
            }
        }
    }

    private var emptyMessage: String {
        if list.totalCount > 0 { return Strings.noResults }
        return model.settings.keepHistory ? Strings.noTranscripts : Strings.historyOff
    }
}

private struct HistoryRow: View {
    @EnvironmentObject private var model: AppModel
    let entry: HistoryEntry
    let isSelected: Bool
    @ObservedObject var list: HistoryViewModel

    var body: some View {
        HStack(alignment: .firstTextBaseline, spacing: Space.s4) {
            Text(entry.date.formatted(Date.FormatStyle().hour().minute().second().locale(dutch)))
                .textStyle(Typography.counterSmall)
                .foregroundStyle(Palette.inkSecondary)
            VStack(alignment: .leading, spacing: Space.s2) {
                Text(markedText)
                    .textStyle(Typography.reading)
                    .foregroundStyle(Palette.inkPrimary)
                    .textSelection(.enabled)
                if !entry.corrections.isEmpty {
                    SilkLabel(correctionSummary, style: Typography.labelSmall)
                }
                if isSelected && entry.rawText != entry.finalText {
                    Text("\(Strings.original): \(entry.rawText)")
                        .textStyle(Typography.meta)
                        .foregroundStyle(Palette.inkSecondary)
                }
            }
            Spacer(minLength: Space.s4)
            Button(Strings.copy) { copy(entry.finalText) }
                .buttonStyle(KeyButtonStyle())
            Button(Strings.edit) { model.edit(entry: entry.id) }
                .buttonStyle(KeyButtonStyle())
            Button(Strings.delete) { list.delete(id: entry.id) }
                .buttonStyle(KeyButtonStyle())
        }
        .padding(.horizontal, Space.s4)
        .padding(.vertical, Space.s3)
        .frame(minHeight: Size.rowHeight)
        .background(isSelected ? Palette.surfaceSelection : Color.clear)
        .contentShape(Rectangle())
        .onTapGesture { list.selection = entry.id }
        .contextMenu {
            Button(Strings.copy) { copy(entry.finalText) }
            Button(Strings.copyOriginal) { copy(entry.rawText) }
            Button(Strings.edit) { model.edit(entry: entry.id) }
            Divider()
            Button(Strings.delete, role: .destructive) { list.delete(id: entry.id) }
        }
    }

    /// The final text with every dictionary replacement highlighted.
    private var markedText: AttributedString {
        var result = AttributedString()
        for segment in CorrectionMarkup.segments(finalText: entry.finalText, corrections: entry.corrections) {
            var piece = AttributedString(segment.text)
            if segment.correction != nil {
                piece.backgroundColor = Palette.levelAmber.opacity(Opacity.mark)
            }
            result += piece
        }
        return result
    }

    private var correctionSummary: String {
        let changes = entry.corrections.map { "\($0.heard) → \($0.wrote)" }.joined(separator: ", ")
        return "\(Strings.corrections(entry.corrections.count)) · \(changes)"
    }

    private func copy(_ text: String) {
        NSPasteboard.general.clearContents()
        NSPasteboard.general.setString(text, forType: .string)
    }
}