// Centralized feature → tier mapping for license entitlements.
//
// This module is the single source of truth for which features are gated by which tier.
// To change what is gated where, modify FEATURE_TIERS only — never sprinkle edition checks
// throughout the codebase.

/// Editions, ordered from least to most privileged.
pub const EDITION_FREE: &str = "free";
pub const EDITION_BASE: &str = "base";
pub const EDITION_PREMIUM: &str = "premium";

/// Maps feature name → list of editions allowed to use it.
/// A feature absent from this list is denied for all editions.
const FEATURE_TIERS: &[(&str, &[&str])] = &[
    ("auto-update", &[EDITION_BASE, EDITION_PREMIUM]),
    ("web-sync", &[EDITION_PREMIUM]),
    ("cloud-backup", &[EDITION_PREMIUM]),
    ("advanced-reports", &[EDITION_PREMIUM]),
];

/// Pure check: does `edition` grant access to `feature`?
pub fn is_feature_allowed(feature: &str, edition: &str) -> bool {
    FEATURE_TIERS
        .iter()
        .find(|(name, _)| *name == feature)
        .map(|(_, tiers)| tiers.contains(&edition))
        .unwrap_or(false)
}

#[tauri::command]
pub fn check_entitlement(app: tauri::AppHandle, feature: String) -> Result<bool, String> {
    let edition = crate::commands::license_commands::current_edition(&app);
    Ok(is_feature_allowed(&feature, &edition))
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn free_blocks_auto_update() {
        assert!(!is_feature_allowed("auto-update", EDITION_FREE));
    }

    #[test]
    fn base_unlocks_auto_update() {
        assert!(is_feature_allowed("auto-update", EDITION_BASE));
    }

    #[test]
    fn premium_unlocks_everything() {
        assert!(is_feature_allowed("auto-update", EDITION_PREMIUM));
        assert!(is_feature_allowed("web-sync", EDITION_PREMIUM));
        assert!(is_feature_allowed("cloud-backup", EDITION_PREMIUM));
    }

    #[test]
    fn base_does_not_unlock_premium_features() {
        assert!(!is_feature_allowed("web-sync", EDITION_BASE));
        assert!(!is_feature_allowed("cloud-backup", EDITION_BASE));
    }

    #[test]
    fn unknown_feature_denied() {
        assert!(!is_feature_allowed("nonexistent", EDITION_PREMIUM));
    }
}