// Theme.swift
// Jarvis — shared design tokens, signal-score fade math, formatting, nav routes.
// Every hex value here is from the spec; nothing is invented.

import SwiftUI

// MARK: - Hex colors

extension Color {
    init(hex: String) {
        let s = hex.trimmingCharacters(in: CharacterSet(charactersIn: "#"))
        var v: UInt64 = 0
        Scanner(string: s).scanHexInt64(&v)
        let r, g, b: Double
        switch s.count {
        case 6:
            r = Double((v >> 16) & 0xFF) / 255
            g = Double((v >> 8) & 0xFF) / 255
            b = Double(v & 0xFF) / 255
        default:
            r = 0; g = 0; b = 0
        }
        self = Color(.sRGB, red: r, green: g, blue: b, opacity: 1)
    }
}

// MARK: - Palette

enum Palette {
    static let orange   = Color("KisaniOrange")     // #FF5C00
    static let black    = Color.black               // #000000
    static let surface  = Color(hex: "111111")
    static let surface2 = Color(hex: "1A1A1A")
    static let hairline = Color(hex: "1A1A1A")

    // health
    static let healthActive  = Color(hex: "2A5A2A")
    static let healthFailing = Color(hex: "AA6600")
    static let healthDead     = Color(hex: "5A1A1A")

    // blocks
    static let consensusBorder = Color(hex: "FF5C00")
    static let consensusFill    = Color(hex: "1F1206")   // dark orange
    static let conflictBorder   = Color(hex: "5A1A1A")   // dark red
    static let conflictFill     = Color(hex: "1A0C0C")   // dark red

    static let cachedGreen = Color(hex: "2A5A2A")
    static let bodyText    = Color(hex: "4A4A4A")
}

// MARK: - Signal-score fade
//
// Spec anchors:
//   stripe : 97 → #FF5C00, fades to #1A1A1A at 0
//   title  : 97 → white,   20 → #444444, 0–19 near invisible
//   score  : 80–100 full orange · 50–79 dimmed orange · 20–49 dark brown · 0–19 near invisible

enum Signal {
    private static func lerp(_ a: (Double, Double, Double),
                             _ b: (Double, Double, Double),
                             _ t: Double) -> Color {
        let t = max(0, min(1, t))
        return Color(.sRGB,
                     red:   a.0 + (b.0 - a.0) * t,
                     green: a.1 + (b.1 - a.1) * t,
                     blue:  a.2 + (b.2 - a.2) * t,
                     opacity: 1)
    }

    /// 3pt left stripe color: #1A1A1A (0) → #FF5C00 (97+).
    static func stripeColor(_ score: Int) -> Color {
        let t = Double(score) / 97.0
        return lerp((0x1A/255, 0x1A/255, 0x1A/255),   // #1A1A1A
                    (0xFF/255, 0x5C/255, 0x00/255),    // #FF5C00
                    t)
    }

    /// Story title color: white (97+) → #444444 (20) → near invisible (0).
    static func titleColor(_ score: Int) -> Color {
        if score >= 97 { return .white }
        if score >= 20 {
            let t = Double(score - 20) / Double(97 - 20)
            return lerp((0x44/255, 0x44/255, 0x44/255), // #444444
                        (1, 1, 1),                       // white
                        t)
        }
        // 0–19 near invisible: #1C1C1C → #444444
        let t = Double(score) / 20.0
        return lerp((0x1C/255, 0x1C/255, 0x1C/255),
                    (0x44/255, 0x44/255, 0x44/255),
                    t)
    }

    /// Signal score number color: stays in orange/brown hue, fades with score.
    /// near-invisible brown (0) → full #FF5C00 (100).
    static func scoreColor(_ score: Int) -> Color {
        let t = Double(score) / 100.0
        return lerp((0x2A/255, 0x18/255, 0x10/255),    // near-invisible brown
                    (0xFF/255, 0x5C/255, 0x00/255),     // #FF5C00
                    t)
    }
}

// MARK: - Topic display

enum Topic {
    static func label(_ slug: String) -> String {
        switch slug.lowercased() {
        case "ai", "artificial-intelligence": return "AI"
        case "us", "united-states":           return "US"
        case "formula-1":                     return "Formula 1"
        case "ui-ux", "web-design-and-ui-ux": return "Web Design"
        default:
            // Slug → Title Case, e.g. "cloud-computing" → "Cloud Computing".
            return slug.split(separator: "-")
                .map { $0.prefix(1).uppercased() + $0.dropFirst() }
                .joined(separator: " ")
        }
    }

    /// Topic pills shown on the home screen.
    static let filters: [(label: String, slug: String?)] = [
        ("All", nil),
        ("Finance", "finance"),
        ("Tech", "tech"),
        ("Politics", "politics"),
        ("Africa", "africa"),
    ]
}

// MARK: - Time formatting

extension Date {
    /// Short relative string e.g. "just now", "3 min", "2 hr", "4 d".
    func timeAgoShort(reference: Date = Date()) -> String {
        let secs = max(0, Int(reference.timeIntervalSince(self)))
        switch secs {
        case 0..<60:        return "just now"
        case 60..<3600:     return "\(secs / 60) min"
        case 3600..<86400:  return "\(secs / 3600) hr"
        default:            return "\(secs / 86400) d"
        }
    }

    /// "08:03" style monospaced clock for timeline / source chips.
    var clockShort: String {
        let f = DateFormatter()
        f.dateFormat = "HH:mm"
        return f.string(from: self)
    }
}

func syncedMinutesAgo(_ date: Date?, reference: Date = Date()) -> String {
    guard let date else { return "never" }
    return date.timeAgoShort(reference: reference)
}

// MARK: - Navigation routes

/// Route into the article reader. Carries the parent story context so the
/// back button can show the truncated headline.
struct ArticleRoute: Hashable {
    let articleId: String
    let storyId: String
    let parentHeadline: String
}

// MARK: - Appearance mode

enum AppearanceMode: String, CaseIterable {
    case system, light, dark

    var colorScheme: ColorScheme? {
        switch self {
        case .system: return nil
        case .light:  return .light
        case .dark:   return .dark
        }
    }

    var label: String {
        switch self {
        case .system: return "System"
        case .light:  return "Light"
        case .dark:   return "Dark"
        }
    }

    var icon: String {
        switch self {
        case .system: return "circle.lefthalf.filled"
        case .light:  return "sun.max"
        case .dark:   return "moon.stars"
        }
    }
}

// MARK: - Stable feed ordering

extension StorySummary {
    /// Deterministic ranking: signal score descending, then id descending — the
    /// same order the backend uses (`signal_score DESC, id DESC`). Without the
    /// id tiebreaker, equal-score stories reshuffle on every (unstable) re-sort.
    static func feedOrder(_ a: StorySummary, _ b: StorySummary) -> Bool {
        a.signalScore != b.signalScore ? a.signalScore > b.signalScore : a.id > b.id
    }
}

// MARK: - Story pills (backend-tag driven)
//
// The backend classifies each story into canonical category slugs in `tags[]`.
// The client filters by pill -> slug membership only; no headline keyword
// matching. `topic` is a fallback while the backend finishes emitting `tags[]`.

enum StoryPill: String, CaseIterable, Identifiable {
    case all = "All"
    case f1 = "F1"
    case sport = "Sport"
    case tech = "Tech"          // covers AI, Cloud, HomeLab — use sub-sections inside
    case uganda = "Uganda"
    case southAfrica = "South Africa"
    case canada = "Canada"
    case unitedStates = "US"

    var id: String { rawValue }
    var label: String { rawValue }

    var slugs: Set<String> {
        switch self {
        case .all:          return []
        case .f1:           return ["formula-1"]
        case .sport:        return ["sports", "esports"]
        case .tech:         return [
            "technology", "programming-and-software-development",
            "cybersecurity", "security", "privacy-and-data-protection",
            "web-design-and-ui-ux", "wordpress-and-web-development",
            "artificial-intelligence", "machine-learning", "robotics",
            "cloud-computing", "homelab",
        ]
        case .uganda:       return ["uganda"]
        case .southAfrica:  return ["south-africa"]
        case .canada:       return ["canada"]
        case .unitedStates: return ["united-states"]
        }
    }

    /// Sub-sections to show inside the card layout for this pill (nil = flat).
    var subSections: [NewsSection]? {
        switch self {
        case .tech: return NewsSection.techSubSections
        default:    return nil
        }
    }
}

extension StorySummary {
    /// Backend `tags[]` are the source of truth; fall back to `topic` during the
    /// transition while the backend finishes emitting tags.
    var effectiveTags: Set<String> {
        let clean = Set((tags ?? []).filter { !$0.isEmpty })
        return clean.isEmpty ? [topic] : clean
    }

    func matches(_ pill: StoryPill) -> Bool {
        pill == .all || !effectiveTags.isDisjoint(with: pill.slugs)
    }

    func inSection(_ section: NewsSection) -> Bool {
        !effectiveTags.isDisjoint(with: section.slugs)
    }
}

// MARK: - Wordmark

struct JarvisWordmark: View {
    var size: CGFloat = 30
    private var font: Font { .custom("Courier New", size: size).bold() }
    var body: some View {
        HStack(spacing: 0) {
            Text("j").font(font).foregroundStyle(Palette.orange)
            Text("arvis").font(font).foregroundStyle(.white)
        }
    }
}

// MARK: - News sections (the "All" front page)
//
// Groups the firehose into Apple/Google-News-style sections. A story lands in
// the first section (by this order) whose slugs it carries; `pill` powers "See all".

struct NewsSection: Identifiable {
    let id: String
    let label: String
    let slugs: Set<String>
    let pill: StoryPill?

    static let sections: [NewsSection] = [
        .init(id: "us",            label: "US",           slugs: ["united-states"], pill: .unitedStates),
        .init(id: "world",         label: "World",        slugs: ["world-news", "news", "news-and-current-affairs"], pill: nil),
        .init(id: "politics",      label: "Politics",     slugs: ["politics", "human-rights", "investigative"], pill: nil),
        .init(id: "business",      label: "Business",     slugs: ["business", "finance", "fintech", "cryptocurrency", "blockchain", "entrepreneur", "startups", "real-estate"], pill: nil),
        .init(id: "tech",          label: "Tech",         slugs: ["technology", "programming-and-software-development", "cybersecurity", "security", "web-design-and-ui-ux", "wordpress-and-web-development", "privacy-and-data-protection", "cloud-computing", "artificial-intelligence", "machine-learning", "robotics", "homelab"], pill: .tech),
        .init(id: "africa",        label: "Africa",       slugs: ["africa", "east-africa", "south-africa", "uganda"], pill: nil),
        .init(id: "sport",         label: "Sport",        slugs: ["sports", "esports", "formula-1"], pill: .sport),
        .init(id: "science",       label: "Science",      slugs: ["science", "astronomy", "environment", "green-technology", "sustainability"], pill: nil),
        .init(id: "entertainment", label: "Entertainment",slugs: ["entertainment", "music", "pop-culture", "video-game", "arts-and-culture", "books-and-literature"], pill: nil),
        .init(id: "health",        label: "Health",       slugs: ["health", "health-and-wellness", "mental-health"], pill: nil),
        .init(id: "lifestyle",     label: "Lifestyle",    slugs: ["lifestyle", "food-and-drink", "travel", "gardening", "outdoor-and-hiking", "parenting-and-family", "interior-design-and-home-decor", "photography", "self-improvement-and-personal-development", "education", "e-learning"], pill: nil),
    ]

    /// Sub-sections shown inside the Tech pill view.
    static let techSubSections: [NewsSection] = [
        .init(id: "t-ai",       label: "AI",         slugs: ["artificial-intelligence", "machine-learning", "robotics"], pill: nil),
        .init(id: "t-cloud",    label: "Cloud",      slugs: ["cloud-computing"], pill: nil),
        .init(id: "t-homelab",  label: "HomeLab",    slugs: ["homelab"], pill: nil),
        .init(id: "t-security", label: "Security",   slugs: ["cybersecurity", "security", "privacy-and-data-protection"], pill: nil),
        .init(id: "t-dev",      label: "Dev",        slugs: ["programming-and-software-development", "web-design-and-ui-ux", "wordpress-and-web-development"], pill: nil),
        .init(id: "t-tech",     label: "Technology", slugs: ["technology"], pill: nil),
    ]
}