import SwiftUI

/// T-iOS-31 · 语音 PTT 的 SwiftUI 状态卡。逻辑全在 `VoicePTT.swift` 的
/// `VoicePTTViewModel` 里 —— 本文件只渲染，从 `VoicePTT.swift` 拆出是为了守住
/// 800 行硬上限（plan §4）。

/// PTT 状态卡：听写中 / 待确认 / 撤销窗口 / 被拒 / 失败 / 结果提示。
/// 底部对齐（贴着麦克风键所在的键栏）；nil 状态不渲染任何东西。
struct VoicePTTBanner: View {
    let model: VoicePTTViewModel

    /// `.idle` 且没有结果提示 ⇒ 整张卡不渲染（终端全屏不被占）。
    private var hasCard: Bool {
        if case .idle = model.phase { return model.noticeText != nil }
        return true
    }

    var body: some View {
        if hasCard {
            card
                .padding(DS.Space.md12)
                .background(.regularMaterial, in: RoundedRectangle(cornerRadius: DS.Radius.md12))
                .overlay(
                    RoundedRectangle(cornerRadius: DS.Radius.md12)
                        .strokeBorder(DS.Palette.hairline, lineWidth: DS.Stroke.hairline)
                )
                .accessibilityIdentifier("terminal.voice.card")
        }
    }

    @ViewBuilder private var card: some View {
        switch model.phase {
        case .requestingPermission:
            label(VoicePTTViewModel.Copy.requesting, systemImage: "mic.badge.plus")
        case .listening(let partial):
            listening(partial: partial)
        case .confirming(let pending):
            confirming(pending)
        case .undoWindow(let pending):
            undoWindow(pending)
        case .denied(let reason):
            notice(reason.message, systemImage: "mic.slash")
        case .failed(let message):
            notice(message, systemImage: "exclamationmark.triangle")
        case .idle:
            if let text = model.noticeText {
                notice(text, systemImage: "info.circle")
            }
        }
    }

    private func label(_ text: String, systemImage: String) -> some View {
        Label(text, systemImage: systemImage)
            .font(DS.Typography.callout)
            .foregroundStyle(DS.Palette.textPrimary)
    }

    private func listening(partial: String) -> some View {
        VStack(alignment: .leading, spacing: DS.Space.xs4) {
            label(VoicePTTViewModel.Copy.listening, systemImage: "waveform")
            if !partial.isEmpty {
                Text(partial)
                    .font(DS.Typography.mono(.callout))
                    .foregroundStyle(DS.Palette.textSecondary)
                    .accessibilityIdentifier("terminal.voice.partial")
            }
            Text(VoicePTTViewModel.Copy.listeningHint)
                .font(DS.Typography.caption)
                .foregroundStyle(DS.Palette.textTertiary)
        }
    }

    private func confirming(_ pending: VoicePendingAction) -> some View {
        VStack(alignment: .leading, spacing: DS.Space.sm8) {
            Text(title(for: pending.intent))
                .font(DS.Typography.callout.weight(.semibold))
                .foregroundStyle(DS.Palette.textPrimary)
            Text(pending.preview)
                .font(DS.Typography.mono(.callout))
                .foregroundStyle(DS.Palette.textPrimary)
                .accessibilityIdentifier("terminal.voice.preview")
            HStack(spacing: DS.Space.sm8) {
                Button(VoicePTTViewModel.Copy.cancel) { model.cancel() }
                    .buttonStyle(.bordered)
                    .accessibilityIdentifier("terminal.voice.cancelButton")
                Button(VoicePTTViewModel.Copy.send) { model.confirm() }
                    .buttonStyle(.borderedProminent)
                    .accessibilityIdentifier("terminal.voice.confirmButton")
            }
            .frame(minHeight: DS.Layout.minHitTarget)
        }
    }

    private func undoWindow(_ pending: VoicePendingAction) -> some View {
        HStack(spacing: DS.Space.sm8) {
            VStack(alignment: .leading, spacing: DS.Space.xs2) {
                Text(pending.intent.isDecision
                    ? VoicePTTViewModel.Copy.deciding
                    : VoicePTTViewModel.Copy.sending)
                    .font(DS.Typography.caption)
                    .foregroundStyle(DS.Palette.textSecondary)
                Text(pending.preview)
                    .font(DS.Typography.mono(.callout))
                    .foregroundStyle(DS.Palette.textPrimary)
            }
            Spacer(minLength: DS.Space.sm8)
            Button(VoicePTTViewModel.Copy.undo) { model.undo() }
                .buttonStyle(.borderedProminent)
                .frame(minHeight: DS.Layout.minHitTarget)
                .accessibilityIdentifier("terminal.voice.undoButton")
        }
    }

    private func notice(_ text: String, systemImage: String) -> some View {
        HStack(spacing: DS.Space.sm8) {
            label(text, systemImage: systemImage)
            Spacer(minLength: DS.Space.sm8)
            Button {
                model.clearNotice()
            } label: {
                Image(systemName: "xmark")
                    .frame(minWidth: DS.Layout.minHitTarget, minHeight: DS.Layout.minHitTarget)
            }
            .buttonStyle(.plain)
            .accessibilityLabel(VoicePTTViewModel.Copy.dismissNotice)
        }
    }

    private func title(for intent: VoiceIntent) -> String {
        switch intent {
        case .text: VoicePTTViewModel.Copy.confirmTitle
        case .decision(.approve): VoicePTTViewModel.Copy.approveTitle
        case .decision(.reject): VoicePTTViewModel.Copy.rejectTitle
        }
    }
}

extension VoiceIntent {
    var isDecision: Bool {
        if case .decision = self { return true }
        return false
    }
}