//! Edit history CRUD operations on `MessageRepo`.
//!
//! Immutable append-only log. Every message body edit creates one row.

use chrono::Utc;
use sqlx::Row;
use uuid::Uuid;

use crate::ImksResult;
use crate::models::message_edit::{EditSummary, MessageEdit};

use super::message_repo::MessageRepo;

impl MessageRepo {
    /// Record an edit to a message's body.
    pub async fn record_edit(
        &self,
        message_id: Uuid,
        edited_by: Uuid,
        old_body: &str,
        new_body: &str,
    ) -> ImksResult<MessageEdit> {
        let id = Uuid::now_v7();
        let now = Utc::now();

        sqlx::query_as::<_, MessageEdit>(
            r#"
            INSERT INTO message_edit (id, message_id, edited_by, old_body, new_body, edited_at)
            VALUES ($1, $2, $3, $4, $5, $6)
            RETURNING *
            "#,
        )
        .bind(id)
        .bind(message_id)
        .bind(edited_by)
        .bind(old_body)
        .bind(new_body)
        .bind(now)
        .fetch_one(self.pool())
        .await
        .map_err(Into::into)
    }

    /// Get the full edit history for a message, oldest first.
    pub async fn get_edit_history(&self, message_id: Uuid) -> ImksResult<Vec<MessageEdit>> {
        sqlx::query_as::<_, MessageEdit>(
            "SELECT * FROM message_edit WHERE message_id = $1 ORDER BY edited_at ASC",
        )
        .bind(message_id)
        .fetch_all(self.pool())
        .await
        .map_err(Into::into)
    }

    /// Get a summary of edits for a message (count + last editor).
    pub async fn get_edit_summary(&self, message_id: Uuid) -> ImksResult<EditSummary> {
        let row = sqlx::query(
            r#"
            SELECT
                COUNT(*)::BIGINT AS edit_count,
                MAX(edited_at) AS last_edited_at,
                (ARRAY_AGG(edited_by ORDER BY edited_at DESC))[1] AS last_edited_by
            FROM message_edit
            WHERE message_id = $1
            "#,
        )
        .bind(message_id)
        .fetch_one(self.pool())
        .await?;

        Ok(EditSummary {
            edit_count: row.get("edit_count"),
            last_edited_at: row.get("last_edited_at"),
            last_edited_by: row.get("last_edited_by"),
        })
    }
}