Gamification System

Watermelon uses a dual-loop progression system to keep users engaged: XP-driven level progression and rank-tier prestige.

XP System

Earning XP

Action	XP	Note
Play a song	+5	Minimum 30s listen
Complete a song	+15	Listen to >80% of track
Daily login streak	+20	Multiplied by streak multiplier
Create a playlist	+25	Per new playlist
Discover new artist	+10	Artist not played before
Maintain streak (3d)	×1.5	3-consecutive-day bonus
Maintain streak (7d)	×2.0	Weekly bonus
Maintain streak (14d)	×2.5	Fortnight bonus
Maintain streak (30d)	×3.0	Monthly bonus

Level Formula

XP Level = GREATEST(1, FLOOR(SQRT(xp_total / 100.0)))

Level	XP Required	Multiplier
1	0	1.0×
2	100	1.1×
3	400	1.2×
5	2,500	1.4×
10	10,000	1.9×
20	40,000	2.9×
30	90,000	3.9×

The multiplier visually reinforces progression even at low levels.

XP Descriptor

fun xpDescriptor(xp: Int): String = when (xp) {
    0 -> "Fresh listener ✨"
    in 1..(100 / 2) -> "Gaining momentum 🔁"
    in (100 / 2)..(100 * 2) -> "Solid start 👊"
    in (100 * 2)..(100 * 5) -> "Groove locked ✨"
    in (100 * 5)..(100 * 10) -> "Addicted 🎶"
    else -> "Music is life 💖"
}

Rank Tiers

Rank is computed automatically from hours listened via PostgreSQL triggers.

Hours	Tier Name	Emoji
0	Seed Listener	🌱
5	Sprout Wave	🍃
15	Pulse Rider	🎧
35	Echo Drift	🌊
60	Resonance	🎶
100	Vinyl Hunter	📀
160	Frequency Soul	🎵
250	NovaBeat	🌌
350	Harmonic Flow	💿
500	Reverb X	🔥
700	Soundrift	⚡
950	Celestia Tone	🌠
1200	Wave Architect	🎼
1600	Spectrum Lord	🌈
2000	Eternal Echo	👑

Achievement Badges

Stored in achievements table and unlocked via triggers on user_actions and play_sessions.

Unlock Rules (trigger-driven)

Badge	Trigger Condition
🎵 First Listen	First `PLAY` action
🦉 Night Owl	Play between 02:00–05:00
🧭 Explorer	10 unique artists in history
📋 Playlist Pro	Create 5 playlists
🐦 Early Bird	Play before 07:00
🏃 Marathoner	`hours_listened >= 50`

Badge Display

// ProfileScreen.kt — vertical card with emoji + description
Card(
    modifier = Modifier.size(170.dp, 120.dp),
    colors = CardDefaults.cardColors(
        containerColor = MaterialTheme.colorScheme.primaryContainer.copy(alpha = 0.6f)
    )
) {
    Column(horizontalAlignment = Alignment.CenterHorizontally) {
        Text(badge.emoji, fontSize = 32.sp)
        Text(badge.name, fontWeight = FontWeight.Bold)
        Text(badge.description, fontSize = 11.sp)
    }
}

Streak System

Streak = consecutive days with at least one play session
Tracked in profiles.streak_days
Daily notification: “Your streak is at 3 days 🔥“

Leaderboard

Updated hourly via cron or trigger:

SELECT
    id,
    display_name,
    email,
    hours_listened,
    songs_played,
    rank_tier,
    xp_level
FROM profiles
WHERE is_banned = false
ORDER BY hours_listened DESC
LIMIT 50;

Live at: /leaderboard

Profile Screen

The profile screen surfaces all gamification data:

Header — Avatar (DiceBear), name, rank badge
Stats Grid — Rank, Level, Hours, Songs, Multiplier
Streak — Current / longest streak
Achievements — Horizontal scrolling badge cards
XPSection — Progress bar to next level with descriptor

For the SQL migration scripts, see the Database Schema guide.

Database Schema UI System