import AppKit
import SwiftUI
import UniformTypeIdentifiers

// MARK: - Page Boundary

struct PostPageBoundary<Content: View>: View {
    @ViewBuilder let content: Content

    var body: some View {
        content
            .padding(20)
            .background(
                RoundedRectangle(cornerRadius: AppTheme.cornerRadius)
                    .fill(AppTheme.panelBackground)
            )
            .overlay(
                RoundedRectangle(cornerRadius: AppTheme.cornerRadius)
                    .stroke(AppTheme.cardBorder, lineWidth: 1)
            )
    }
}

// MARK: - Shared Form Components

struct PostFormCard<Content: View>: View {
    let title: String
    var subtitle: String?
    @ViewBuilder let content: Content

    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            VStack(alignment: .leading, spacing: 2) {
                Text(title)
                    .font(.system(size: 12, weight: .semibold))
                    .foregroundStyle(AppTheme.textPrimary)
                if let subtitle {
                    Text(subtitle)
                        .font(.system(size: 10))
                        .foregroundStyle(AppTheme.textSecondary)
                }
            }

            content
        }
        .padding(14)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(
            RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                .fill(AppTheme.cardBackground)
                .overlay(
                    RoundedRectangle(cornerRadius: AppTheme.cornerRadiusSmall)
                        .stroke(AppTheme.cardBorder, lineWidth: 1)
                )
        )
    }
}

struct PostFormField: View {
    let label: String
    var placeholder: String = ""
    @Binding var text: String
    var prefix: String?

    var body: some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(label)
                .font(.system(size: 10, weight: .medium))
                .foregroundStyle(AppTheme.textTertiary)

            HStack(spacing: 0) {
                if let prefix {
                    Text(prefix)
                        .font(.system(size: 12, weight: .medium))
                        .foregroundStyle(AppTheme.textSecondary)
                        .padding(.leading, 10)
                }

                TextField(placeholder, text: $text)
                    .textFieldStyle(.plain)
                    .font(.system(size: 12))
                    .foregroundStyle(AppTheme.textPrimary)
                    .padding(.horizontal, prefix == nil ? 10 : 4)
                    .padding(.vertical, 8)
            }
            .background(AppTheme.panelBackground)
            .clipShape(RoundedRectangle(cornerRadius: 8))
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(AppTheme.cardBorder, lineWidth: 1)
            )
        }
    }
}

struct PostFormTextEditor: View {
    let label: String
    var placeholder: String = ""
    @Binding var text: String
    var minHeight: CGFloat = 120

    var body: some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(label)
                .font(.system(size: 10, weight: .medium))
                .foregroundStyle(AppTheme.textTertiary)

            ZStack(alignment: .topLeading) {
                if text.isEmpty {
                    Text(placeholder)
                        .font(.system(size: 12))
                        .foregroundStyle(AppTheme.textTertiary.opacity(0.7))
                        .padding(.horizontal, 8)
                        .padding(.vertical, 10)
                }

                TextEditor(text: $text)
                    .font(.system(size: 12))
                    .foregroundStyle(AppTheme.textPrimary)
                    .scrollContentBackground(.hidden)
                    .padding(.horizontal, 4)
                    .padding(.vertical, 4)
            }
            .frame(minHeight: minHeight)
            .background(AppTheme.panelBackground)
            .clipShape(RoundedRectangle(cornerRadius: 8))
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(AppTheme.cardBorder, lineWidth: 1)
            )
        }
    }
}

struct PostTypePicker: View {
    @Binding var selectedType: RedditPostType

    var body: some View {
        LazyVGrid(
            columns: [GridItem(.flexible()), GridItem(.flexible())],
            spacing: 8
        ) {
            ForEach(RedditPostType.allCases) { type in
                PostTypeButton(type: type, isSelected: selectedType == type) {
                    selectedType = type
                }
            }
        }
    }
}

private struct PostTypeButton: View {
    let type: RedditPostType
    let isSelected: Bool
    let action: () -> Void

    var body: some View {
        Button(action: action) {
            HStack(spacing: 8) {
                Image(systemName: type.systemImage)
                    .font(.system(size: 12, weight: .semibold))
                    .foregroundStyle(isSelected ? AppTheme.accentPurpleLight : AppTheme.textSecondary)
                    .frame(width: 16)

                VStack(alignment: .leading, spacing: 1) {
                    Text(type.title)
                        .font(.system(size: 11, weight: .semibold))
                        .foregroundStyle(AppTheme.textPrimary)
                    Text(type.subtitle)
                        .font(.system(size: 9))
                        .foregroundStyle(AppTheme.textTertiary)
                        .lineLimit(1)
                }

                Spacer(minLength: 0)
            }
            .padding(.horizontal, 10)
            .padding(.vertical, 8)
            .background(
                RoundedRectangle(cornerRadius: 8)
                    .fill(isSelected ? AppTheme.accentPurple.opacity(0.15) : AppTheme.panelBackground)
            )
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(
                        isSelected ? AppTheme.accentPurple.opacity(0.5) : AppTheme.cardBorder,
                        lineWidth: 1
                    )
            )
        }
        .buttonStyle(.plain)
    }
}

struct PostTagToggle: View {
    let title: String
    let systemImage: String
    let activeColor: Color
    @Binding var isOn: Bool

    var body: some View {
        Button {
            isOn.toggle()
        } label: {
            HStack(spacing: 5) {
                Image(systemName: systemImage)
                    .font(.system(size: 10, weight: .semibold))
                Text(title)
                    .font(.system(size: 10, weight: .semibold))
            }
            .foregroundStyle(isOn ? activeColor : AppTheme.textSecondary)
            .padding(.horizontal, 10)
            .padding(.vertical, 6)
            .background(
                RoundedRectangle(cornerRadius: 6)
                    .fill(isOn ? activeColor.opacity(0.15) : AppTheme.panelBackground)
            )
            .overlay(
                RoundedRectangle(cornerRadius: 6)
                    .stroke(isOn ? activeColor.opacity(0.4) : AppTheme.cardBorder, lineWidth: 1)
            )
        }
        .buttonStyle(.plain)
    }
}

struct TonePicker: View {
    @Binding var selectedTone: PostTone

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 6) {
                ForEach(PostTone.allCases) { tone in
                    Button {
                        selectedTone = tone
                    } label: {
                        Text(tone.title)
                            .font(.system(size: 10, weight: .semibold))
                            .foregroundStyle(selectedTone == tone ? .white : AppTheme.textSecondary)
                            .padding(.horizontal, 10)
                            .padding(.vertical, 6)
                            .background(
                                Capsule()
                                    .fill(selectedTone == tone ? AppTheme.accentPurple : AppTheme.panelBackground)
                            )
                            .overlay(
                                Capsule()
                                    .stroke(
                                        selectedTone == tone ? AppTheme.accentPurple.opacity(0.5) : AppTheme.cardBorder,
                                        lineWidth: 1
                                    )
                            )
                    }
                    .buttonStyle(.plain)
                }
            }
        }
    }
}

struct PostGeneratorMessageBanner: View {
    let message: String
    let isError: Bool

    var body: some View {
        HStack(spacing: 8) {
            Image(systemName: isError ? "exclamationmark.circle.fill" : "checkmark.circle.fill")
                .font(.system(size: 12))
            Text(message)
                .font(.system(size: 11))
        }
        .foregroundStyle(isError ? Color(hex: 0xF87171) : AppTheme.accentGreen)
        .padding(.horizontal, 12)
        .padding(.vertical, 8)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(
            RoundedRectangle(cornerRadius: 8)
                .fill((isError ? Color(hex: 0xF87171) : AppTheme.accentGreen).opacity(0.1))
        )
    }
}

// MARK: - Markdown

struct PostMarkdownText: View {
    let text: String
    var fontSize: CGFloat = 12
    var color: Color = AppTheme.textSecondary
    var lineSpacing: CGFloat = 3

    var body: some View {
        if let attributed = try? AttributedString(
            markdown: text,
            options: AttributedString.MarkdownParsingOptions(interpretedSyntax: .inlineOnlyPreservingWhitespace)
        ) {
            Text(attributed)
                .font(.system(size: fontSize))
                .foregroundStyle(color)
                .lineSpacing(lineSpacing)
                .fixedSize(horizontal: false, vertical: true)
                .textSelection(.enabled)
        } else {
            Text(text)
                .font(.system(size: fontSize))
                .foregroundStyle(color)
                .lineSpacing(lineSpacing)
                .fixedSize(horizontal: false, vertical: true)
                .textSelection(.enabled)
        }
    }
}

// MARK: - Reddit Preview Card

struct RedditPostPreviewCard: View {
    let draft: PostDraft
    let formattedSubreddit: String

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            previewHeader
            previewContent
        }
        .background(AppTheme.panelBackground)
        .clipShape(RoundedRectangle(cornerRadius: AppTheme.cornerRadius))
        .overlay(
            RoundedRectangle(cornerRadius: AppTheme.cornerRadius)
                .stroke(AppTheme.cardBorder, lineWidth: 1)
        )
    }

    private var previewHeader: some View {
        HStack(spacing: 8) {
            Circle()
                .fill(
                    LinearGradient(
                        colors: [AppTheme.accentOrange, AppTheme.accentOrange.opacity(0.7)],
                        startPoint: .topLeading,
                        endPoint: .bottomTrailing
                    )
                )
                .frame(width: 28, height: 28)
                .overlay {
                    Image(systemName: "person.fill")
                        .font(.system(size: 12))
                        .foregroundStyle(.white)
                }

            VStack(alignment: .leading, spacing: 1) {
                HStack(spacing: 4) {
                    Text(formattedSubreddit)
                        .font(.system(size: 11, weight: .semibold))
                        .foregroundStyle(AppTheme.textPrimary)
                    if !draft.flair.isEmpty {
                        Text(draft.flair)
                            .font(.system(size: 9, weight: .semibold))
                            .foregroundStyle(AppTheme.accentBlue)
                            .padding(.horizontal, 6)
                            .padding(.vertical, 2)
                            .background(AppTheme.accentBlue.opacity(0.15))
                            .clipShape(Capsule())
                    }
                }
                Text("u/ReddoraUser · just now")
                    .font(.system(size: 9))
                    .foregroundStyle(AppTheme.textTertiary)
            }

            Spacer()

            previewTags
        }
        .padding(.horizontal, 14)
        .padding(.top, 14)
        .padding(.bottom, 10)
    }

    @ViewBuilder
    private var previewTags: some View {
        HStack(spacing: 4) {
            if draft.isNSFW {
                previewTag("NSFW", color: Color(hex: 0xEF4444))
            }
            if draft.isSpoiler {
                previewTag("Spoiler", color: AppTheme.textSecondary)
            }
            if draft.isOC {
                previewTag("OC", color: AppTheme.accentGreen)
            }
        }
    }

    private func previewTag(_ text: String, color: Color) -> some View {
        Text(text)
            .font(.system(size: 8, weight: .bold))
            .foregroundStyle(color)
            .padding(.horizontal, 5)
            .padding(.vertical, 2)
            .background(color.opacity(0.15))
            .clipShape(RoundedRectangle(cornerRadius: 3))
    }

    @ViewBuilder
    private var previewContent: some View {
        VStack(alignment: .leading, spacing: 10) {
            Text(draft.title.isEmpty ? "Your post title will appear here" : draft.title)
                .font(.system(size: 14, weight: .semibold))
                .foregroundStyle(draft.title.isEmpty ? AppTheme.textTertiary : AppTheme.textPrimary)
                .fixedSize(horizontal: false, vertical: true)

            switch draft.postType {
            case .text:
                textPreview
            case .image:
                imagePreview
            case .link:
                linkPreview
            case .video:
                videoPreview
            case .poll:
                pollPreview
            }
        }
        .padding(.horizontal, 14)
        .padding(.bottom, 14)
    }

    @ViewBuilder
    private var textPreview: some View {
        if !draft.body.isEmpty {
            PostMarkdownText(text: draft.body)
        }
    }

    @ViewBuilder
    private var imagePreview: some View {
        if let url = draft.imageFileURL, let nsImage = NSImage(contentsOf: url) {
            Image(nsImage: nsImage)
                .resizable()
                .aspectRatio(contentMode: .fit)
                .frame(maxHeight: 200)
                .clipShape(RoundedRectangle(cornerRadius: 8))
        } else {
            imagePlaceholder(icon: "photo", label: "Image preview")
        }

        if !draft.body.isEmpty {
            PostMarkdownText(text: draft.body, fontSize: 11)
        }
    }

    @ViewBuilder
    private var linkPreview: some View {
        linkCard(
            domain: linkDomain,
            title: draft.linkURL.isEmpty ? "Link preview" : draft.title,
            url: draft.linkURL
        )

        if !draft.body.isEmpty {
            PostMarkdownText(text: draft.body, fontSize: 11)
        }
    }

    @ViewBuilder
    private var videoPreview: some View {
        if draft.videoURL.isEmpty {
            imagePlaceholder(icon: "play.rectangle", label: "Video preview")
        } else {
            linkCard(
                domain: videoDomain,
                title: draft.title.isEmpty ? "Video link" : draft.title,
                url: draft.videoURL
            )
        }

        if !draft.body.isEmpty {
            PostMarkdownText(text: draft.body, fontSize: 11)
        }
    }

    @ViewBuilder
    private var pollPreview: some View {
        if !draft.body.isEmpty {
            PostMarkdownText(text: draft.body, fontSize: 11)
        }

        VStack(spacing: 6) {
            ForEach(draft.pollOptions) { option in
                HStack {
                    Text(option.text.isEmpty ? "Poll option" : option.text)
                        .font(.system(size: 11))
                        .foregroundStyle(option.text.isEmpty ? AppTheme.textTertiary : AppTheme.textPrimary)
                    Spacer()
                    Circle()
                        .stroke(AppTheme.cardBorder, lineWidth: 1.5)
                        .frame(width: 14, height: 14)
                }
                .padding(.horizontal, 10)
                .padding(.vertical, 8)
                .background(AppTheme.cardBackground)
                .clipShape(RoundedRectangle(cornerRadius: 6))
            }
        }

        Text("Poll ends in \(draft.pollDuration.label)")
            .font(.system(size: 9))
            .foregroundStyle(AppTheme.textTertiary)
    }

    private func imagePlaceholder(icon: String, label: String) -> some View {
        RoundedRectangle(cornerRadius: 8)
            .fill(AppTheme.cardBackground)
            .frame(height: 140)
            .overlay {
                VStack(spacing: 6) {
                    Image(systemName: icon)
                        .font(.system(size: 24))
                        .foregroundStyle(AppTheme.textTertiary)
                    Text(label)
                        .font(.system(size: 10))
                        .foregroundStyle(AppTheme.textTertiary)
                }
            }
    }

    private func linkCard(domain: String, title: String, url: String) -> some View {
        HStack(spacing: 10) {
            RoundedRectangle(cornerRadius: 6)
                .fill(AppTheme.cardBackground)
                .frame(width: 60, height: 60)
                .overlay {
                    Image(systemName: "link")
                        .font(.system(size: 18))
                        .foregroundStyle(AppTheme.textTertiary)
                }

            VStack(alignment: .leading, spacing: 3) {
                Text(domain.isEmpty ? "example.com" : domain)
                    .font(.system(size: 9))
                    .foregroundStyle(AppTheme.textTertiary)
                Text(title)
                    .font(.system(size: 11, weight: .medium))
                    .foregroundStyle(AppTheme.textPrimary)
                    .lineLimit(2)
            }

            Spacer(minLength: 0)
        }
        .padding(10)
        .background(AppTheme.cardBackground)
        .clipShape(RoundedRectangle(cornerRadius: 8))
        .overlay(
            RoundedRectangle(cornerRadius: 8)
                .stroke(AppTheme.cardBorder, lineWidth: 1)
        )
    }

    private var linkDomain: String {
        guard let url = URL(string: draft.linkURL), let host = url.host else { return "" }
        return host
    }

    private var videoDomain: String {
        guard let url = URL(string: draft.videoURL), let host = url.host else { return "" }
        return host
    }
}