//
//  ChapterReaderView.swift
//  Bible-Week
//
//  Seleciona o capítulo e exibe o texto dos versículos.
//

import SwiftUI

struct ChapterReaderView: View {
    let book: Book

    @State private var selectedChapter = 1
    @State private var chapter: Chapter?
    @State private var isLoading = false
    @State private var errorMessage: String?

    var body: some View {
        VStack(spacing: 0) {
            chapterPicker
            Divider()
            content
        }
        .navigationTitle(book.name)
        .navigationBarTitleDisplayMode(.inline)
        .task(id: selectedChapter) {
            await loadChapter()
        }
    }

    /// Seletor horizontal com todos os capítulos do livro.
    private var chapterPicker: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 8) {
                ForEach(1...book.chapterCount, id: \.self) { number in
                    Button {
                        selectedChapter = number
                    } label: {
                        Text("\(number)")
                            .font(.subheadline.weight(.medium))
                            .frame(minWidth: 36, minHeight: 36)
                            .background(
                                Circle()
                                    .fill(number == selectedChapter ? Color.accentColor : Color(.secondarySystemBackground))
                            )
                            .foregroundStyle(number == selectedChapter ? .white : .primary)
                    }
                }
            }
            .padding(.horizontal)
            .padding(.vertical, 8)
        }
    }

    @ViewBuilder
    private var content: some View {
        if isLoading {
            Spacer()
            ProgressView("Carregando capítulo...")
            Spacer()
        } else if let errorMessage {
            Spacer()
            ContentUnavailableView {
                Label("Erro ao carregar", systemImage: "exclamationmark.triangle")
            } description: {
                Text(errorMessage)
            } actions: {
                Button("Tentar novamente") { Task { await loadChapter() } }
            }
            Spacer()
        } else if let chapter {
            ScrollView {
                VStack(alignment: .leading, spacing: 12) {
                    ForEach(chapter.verses) { verse in
                        Text("\(Text("\(verse.verse)").font(.caption2).foregroundColor(.accentColor).baselineOffset(4)) \(verse.text)")
                            .font(.body)
                            .fixedSize(horizontal: false, vertical: true)
                    }
                }
                .padding()
                .frame(maxWidth: .infinity, alignment: .leading)
            }
        }
    }

    private func loadChapter() async {
        isLoading = true
        errorMessage = nil
        defer { isLoading = false }
        do {
            chapter = try await BibleAPI.chapter(book: book.code, chapter: selectedChapter)
        } catch {
            errorMessage = "Verifique sua conexão e tente novamente."
        }
    }
}