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//! Domain diff logic for schema migrations
use crate::catalog::domain::Domain;
use crate::diff::comment_utils;
use crate::diff::operations::{DomainIdentifier, DomainOperation, MigrationStep};
/// Build the CREATE DOMAIN definition string
fn build_domain_definition(domain: &Domain) -> String {
let mut parts = vec![format!("AS {}", domain.base_type)];
if let Some(default) = &domain.default {
parts.push(format!("DEFAULT {}", default));
}
if domain.not_null {
parts.push("NOT NULL".to_string());
}
if let Some(collation) = &domain.collation {
parts.push(format!("COLLATE \"{}\"", collation));
}
for constraint in &domain.check_constraints {
// pg_get_constraintdef returns the full CHECK clause
parts.push(format!(
"CONSTRAINT {} {}",
constraint.name, constraint.expression
));
}
parts.join(" ")
}
/// Diff a single domain
pub fn diff(old: Option<&Domain>, new: Option<&Domain>) -> Vec<MigrationStep> {
match (old, new) {
// CREATE new domain
(None, Some(n)) => {
let mut steps = vec![MigrationStep::Domain(DomainOperation::Create {
schema: n.schema.clone(),
name: n.name.clone(),
definition: build_domain_definition(n),
})];
// Add domain comment if present
if let Some(comment_op) = comment_utils::handle_comment_creation(
&n.comment,
DomainIdentifier {
schema: n.schema.clone(),
name: n.name.clone(),
},
) {
steps.push(MigrationStep::Domain(DomainOperation::Comment(comment_op)));
}
steps
}
// DROP removed domain
(Some(o), None) => {
vec![MigrationStep::Domain(DomainOperation::Drop {
schema: o.schema.clone(),
name: o.name.clone(),
})]
}
// ALTER existing domain
(Some(o), Some(n)) => {
let mut steps = Vec::new();
// Check if base type or collation changed - requires drop/recreate
if o.base_type != n.base_type || o.collation != n.collation {
// Drop and recreate
steps.push(MigrationStep::Domain(DomainOperation::Drop {
schema: o.schema.clone(),
name: o.name.clone(),
}));
steps.push(MigrationStep::Domain(DomainOperation::Create {
schema: n.schema.clone(),
name: n.name.clone(),
definition: build_domain_definition(n),
}));
// Add domain comment if present
if let Some(comment_op) = comment_utils::handle_comment_creation(
&n.comment,
DomainIdentifier {
schema: n.schema.clone(),
name: n.name.clone(),
},
) {
steps.push(MigrationStep::Domain(DomainOperation::Comment(comment_op)));
}
return steps;
}
// Handle NOT NULL changes
if o.not_null != n.not_null {
if n.not_null {
steps.push(MigrationStep::Domain(DomainOperation::AlterSetNotNull {
schema: n.schema.clone(),
name: n.name.clone(),
}));
} else {
steps.push(MigrationStep::Domain(DomainOperation::AlterDropNotNull {
schema: n.schema.clone(),
name: n.name.clone(),
}));
}
}
// Handle DEFAULT changes
match (&o.default, &n.default) {
(None, Some(new_default)) => {
steps.push(MigrationStep::Domain(DomainOperation::AlterSetDefault {
schema: n.schema.clone(),
name: n.name.clone(),
default: new_default.clone(),
}));
}
(Some(_), None) => {
steps.push(MigrationStep::Domain(DomainOperation::AlterDropDefault {
schema: n.schema.clone(),
name: n.name.clone(),
}));
}
(Some(old_default), Some(new_default)) if old_default != new_default => {
steps.push(MigrationStep::Domain(DomainOperation::AlterSetDefault {
schema: n.schema.clone(),
name: n.name.clone(),
default: new_default.clone(),
}));
}
_ => {}
}
// Handle CHECK constraint changes
// Build maps of constraints by name for comparison
let old_constraints: std::collections::HashMap<&str, &str> = o
.check_constraints
.iter()
.map(|c| (c.name.as_str(), c.expression.as_str()))
.collect();
let new_constraints: std::collections::HashMap<&str, &str> = n
.check_constraints
.iter()
.map(|c| (c.name.as_str(), c.expression.as_str()))
.collect();
// Drop constraints that no longer exist or have changed expression
for (name, old_expr) in &old_constraints {
match new_constraints.get(name) {
None => {
// Constraint was removed
steps.push(MigrationStep::Domain(DomainOperation::DropConstraint {
schema: n.schema.clone(),
name: n.name.clone(),
constraint_name: name.to_string(),
}));
}
Some(new_expr) if old_expr != new_expr => {
// Constraint expression changed - drop and re-add
steps.push(MigrationStep::Domain(DomainOperation::DropConstraint {
schema: n.schema.clone(),
name: n.name.clone(),
constraint_name: name.to_string(),
}));
}
_ => {}
}
}
// Add new constraints or re-add changed constraints
for constraint in &n.check_constraints {
let name = constraint.name.as_str();
match old_constraints.get(name) {
None => {
// New constraint
steps.push(MigrationStep::Domain(DomainOperation::AddConstraint {
schema: n.schema.clone(),
name: n.name.clone(),
constraint_name: constraint.name.clone(),
expression: constraint.expression.clone(),
}));
}
Some(old_expr) if *old_expr != constraint.expression.as_str() => {
// Changed constraint - re-add after drop
steps.push(MigrationStep::Domain(DomainOperation::AddConstraint {
schema: n.schema.clone(),
name: n.name.clone(),
constraint_name: constraint.name.clone(),
expression: constraint.expression.clone(),
}));
}
_ => {}
}
}
// Handle comment changes
let comment_ops =
comment_utils::handle_comment_diff(Some(o), Some(n), || DomainIdentifier {
schema: n.schema.clone(),
name: n.name.clone(),
});
for comment_op in comment_ops {
steps.push(MigrationStep::Domain(DomainOperation::Comment(comment_op)));
}
steps
}
(None, None) => Vec::new(),
}
}