//! Message edit history — maps to `message_edit` table.
//!
//! Immutable append-only log of every edit to a message.
//! Used for audit trails, "edited" indicators with hover-to-see-original,
//! and compliance / moderation review.

use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use uuid::Uuid;

/// One edit record. Stored every time a message body is modified.
#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
pub struct MessageEdit {
    pub id: Uuid,
    pub message_id: Uuid,
    /// Who made the edit (usually the author; can be a moderator).
    pub edited_by: Uuid,
    /// Body content before the edit.
    pub old_body: String,
    /// Body content after the edit.
    pub new_body: String,
    pub edited_at: DateTime<Utc>,
}

/// Lightweight summary for the "edited" tooltip (no full body).
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EditSummary {
    pub edit_count: i64,
    pub last_edited_at: Option<DateTime<Utc>>,
    pub last_edited_by: Option<Uuid>,
}

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

    #[test]
    fn test_message_edit_serialize() {
        let edit = MessageEdit {
            id: Uuid::now_v7(),
            message_id: Uuid::now_v7(),
            edited_by: Uuid::now_v7(),
            old_body: "before edit".to_string(),
            new_body: "after edit".to_string(),
            edited_at: Utc::now(),
        };

        let json = serde_json::to_value(&edit).unwrap();
        assert_eq!(json["old_body"], "before edit");
        assert_eq!(json["new_body"], "after edit");
    }

    #[test]
    fn test_edit_summary_serialize() {
        let summary = EditSummary {
            edit_count: 3,
            last_edited_at: Some(Utc::now()),
            last_edited_by: Some(Uuid::now_v7()),
        };

        let json = serde_json::to_value(&summary).unwrap();
        assert_eq!(json["edit_count"], 3);
    }

    #[test]
    fn test_edit_summary_no_edits() {
        let summary = EditSummary {
            edit_count: 0,
            last_edited_at: None,
            last_edited_by: None,
        };

        let json = serde_json::to_value(&summary).unwrap();
        assert_eq!(json["edit_count"], 0);
        assert!(json["last_edited_at"].is_null());
    }
}