2 files changed, 239 insertions, 1 deletions
diff --git a/makima/src/db/models.rs b/makima/src/db/models.rs
index 8204b86..617e590 100644
--- a/makima/src/db/models.rs
+++ b/makima/src/db/models.rs
@@ -149,3 +149,99 @@ impl From<File> for FileSummary {
         }
     }
 }
+
+// =============================================================================
+// Version History Types
+// =============================================================================
+
+/// Source of a version change
+#[derive(Debug, Clone, Serialize, Deserialize, ToSchema, sqlx::Type)]
+#[sqlx(type_name = "varchar")]
+#[serde(rename_all = "lowercase")]
+pub enum VersionSource {
+    #[sqlx(rename = "user")]
+    User,
+    #[sqlx(rename = "llm")]
+    Llm,
+    #[sqlx(rename = "system")]
+    System,
+}
+
+impl std::fmt::Display for VersionSource {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            VersionSource::User => write!(f, "user"),
+            VersionSource::Llm => write!(f, "llm"),
+            VersionSource::System => write!(f, "system"),
+        }
+    }
+}
+
+impl std::str::FromStr for VersionSource {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "user" => Ok(VersionSource::User),
+            "llm" => Ok(VersionSource::Llm),
+            "system" => Ok(VersionSource::System),
+            _ => Err(format!("Unknown version source: {}", s)),
+        }
+    }
+}
+
+/// Full version record from the database
+#[derive(Debug, Clone, FromRow, Serialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct FileVersion {
+    pub id: Uuid,
+    pub file_id: Uuid,
+    pub version: i32,
+    pub name: String,
+    pub description: Option<String>,
+    pub summary: Option<String>,
+    #[sqlx(json)]
+    pub body: Vec<BodyElement>,
+    pub source: String,
+    pub change_description: Option<String>,
+    pub created_at: DateTime<Utc>,
+}
+
+/// Summary of a version for list views
+#[derive(Debug, Clone, Serialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct FileVersionSummary {
+    pub version: i32,
+    pub source: String,
+    pub created_at: DateTime<Utc>,
+    pub change_description: Option<String>,
+}
+
+impl From<FileVersion> for FileVersionSummary {
+    fn from(v: FileVersion) -> Self {
+        Self {
+            version: v.version,
+            source: v.source,
+            created_at: v.created_at,
+            change_description: v.change_description,
+        }
+    }
+}
+
+/// Response for version list endpoint
+#[derive(Debug, Serialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct FileVersionListResponse {
+    pub versions: Vec<FileVersionSummary>,
+    pub total: i64,
+}
+
+/// Request to restore a file to a previous version
+#[derive(Debug, Deserialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct RestoreVersionRequest {
+    /// The version to restore to
+    pub target_version: i32,
+    /// The current version (for optimistic locking)
+    pub current_version: i32,
+}
diff --git a/makima/src/db/repository.rs b/makima/src/db/repository.rs
index 5b962ee..4137ba6 100644
--- a/makima/src/db/repository.rs
+++ b/makima/src/db/repository.rs
@@ -4,7 +4,7 @@ use chrono::Utc;
 use sqlx::PgPool;
 use uuid::Uuid;
 
-use super::models::{CreateFileRequest, File, UpdateFileRequest};
+use super::models::{CreateFileRequest, File, FileVersion, UpdateFileRequest};
 
 /// Default owner ID for anonymous users.
 pub const ANONYMOUS_OWNER_ID: Uuid = Uuid::from_u128(0x00000000_0000_0000_0000_000000000002);
@@ -221,3 +221,145 @@ pub async fn count_files(pool: &PgPool) -> Result<i64, sqlx::Error> {
 
     Ok(result.0)
 }
+
+// =============================================================================
+// Version History Functions
+// =============================================================================
+
+/// Set the version source for the current transaction.
+/// This is used by the trigger to record who made the change.
+pub async fn set_version_source(pool: &PgPool, source: &str) -> Result<(), sqlx::Error> {
+    sqlx::query(&format!("SET LOCAL app.version_source = '{}'", source))
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+/// Set the change description for the current transaction.
+pub async fn set_change_description(pool: &PgPool, description: &str) -> Result<(), sqlx::Error> {
+    // Escape single quotes for SQL
+    let escaped = description.replace('\'', "''");
+    sqlx::query(&format!("SET LOCAL app.change_description = '{}'", escaped))
+        .execute(pool)
+        .await?;
+    Ok(())
+}
+
+/// List all versions of a file, ordered by version DESC.
+pub async fn list_file_versions(pool: &PgPool, file_id: Uuid) -> Result<Vec<FileVersion>, sqlx::Error> {
+    // First get the current version from the files table
+    let current = get_file(pool, file_id).await?;
+
+    let mut versions = sqlx::query_as::<_, FileVersion>(
+        r#"
+        SELECT id, file_id, version, name, description, summary, body, source, change_description, created_at
+        FROM file_versions
+        WHERE file_id = $1
+        ORDER BY version DESC
+        "#,
+    )
+    .bind(file_id)
+    .fetch_all(pool)
+    .await?;
+
+    // Add the current version as the first entry if it exists
+    if let Some(file) = current {
+        let current_version = FileVersion {
+            id: file.id,
+            file_id: file.id,
+            version: file.version,
+            name: file.name,
+            description: file.description,
+            summary: file.summary,
+            body: file.body,
+            source: "user".to_string(), // Current version source
+            change_description: None,
+            created_at: file.updated_at,
+        };
+        versions.insert(0, current_version);
+    }
+
+    Ok(versions)
+}
+
+/// Get a specific version of a file.
+pub async fn get_file_version(
+    pool: &PgPool,
+    file_id: Uuid,
+    version: i32,
+) -> Result<Option<FileVersion>, sqlx::Error> {
+    // First check if this is the current version
+    if let Some(file) = get_file(pool, file_id).await? {
+        if file.version == version {
+            return Ok(Some(FileVersion {
+                id: file.id,
+                file_id: file.id,
+                version: file.version,
+                name: file.name,
+                description: file.description,
+                summary: file.summary,
+                body: file.body,
+                source: "user".to_string(),
+                change_description: None,
+                created_at: file.updated_at,
+            }));
+        }
+    }
+
+    // Otherwise, look in the versions table
+    sqlx::query_as::<_, FileVersion>(
+        r#"
+        SELECT id, file_id, version, name, description, summary, body, source, change_description, created_at
+        FROM file_versions
+        WHERE file_id = $1 AND version = $2
+        "#,
+    )
+    .bind(file_id)
+    .bind(version)
+    .fetch_optional(pool)
+    .await
+}
+
+/// Restore a file to a previous version.
+/// This creates a new version with the content from the target version.
+pub async fn restore_file_version(
+    pool: &PgPool,
+    file_id: Uuid,
+    target_version: i32,
+    current_version: i32,
+) -> Result<Option<File>, RepositoryError> {
+    // Get the target version content
+    let target = get_file_version(pool, file_id, target_version).await?;
+    let Some(target) = target else {
+        return Ok(None);
+    };
+
+    // Set version source and description for the trigger
+    set_version_source(pool, "system").await?;
+    set_change_description(pool, &format!("Restored from version {}", target_version)).await?;
+
+    // Update the file with the target version's content
+    // This will trigger the save_file_version trigger to save the current state first
+    let update_req = UpdateFileRequest {
+        name: Some(target.name),
+        description: target.description,
+        transcript: None,
+        summary: target.summary,
+        body: Some(target.body),
+        version: Some(current_version),
+    };
+
+    update_file(pool, file_id, update_req).await
+}
+
+/// Count versions for a file.
+pub async fn count_file_versions(pool: &PgPool, file_id: Uuid) -> Result<i64, sqlx::Error> {
+    let result: (i64,) = sqlx::query_as(
+        "SELECT COUNT(*) + 1 FROM file_versions WHERE file_id = $1", // +1 for current version
+    )
+    .bind(file_id)
+    .fetch_one(pool)
+    .await?;
+
+    Ok(result.0)
+}