vespertide-query 0.2.1

use sea_query::Alias;

use vespertide_core::TableDef;

use super::helpers::{build_sea_column_def_with_table, quote_ident};
use super::types::{BuiltQuery, DatabaseBackend, RawSql};
use crate::error::QueryError;

/// Build SQL for changing column comment.
/// Note: `SQLite` does not support column comments natively.
pub fn build_modify_column_comment(
    backend: DatabaseBackend,
    table: &str,
    column: &str,
    new_comment: Option<&str>,
    current_schema: &[TableDef],
) -> Result<Vec<BuiltQuery>, QueryError> {
    let mut queries = Vec::new();

    match backend {
        DatabaseBackend::Postgres => {
            let quoted_table = quote_ident(table, backend);
            let quoted_column = quote_ident(column, backend);
            let comment_sql = if let Some(comment) = new_comment {
                // Escape single quotes in comment
                let escaped = comment.replace('\'', "''");
                format!("COMMENT ON COLUMN {quoted_table}.{quoted_column} IS '{escaped}'")
            } else {
                format!("COMMENT ON COLUMN {quoted_table}.{quoted_column} IS NULL")
            };
            queries.push(BuiltQuery::Raw(RawSql::uniform(comment_sql)));
        }
        DatabaseBackend::MySql => {
            // MySQL requires the full column definition in MODIFY COLUMN to change comment
            let table_def = current_schema
                .iter()
                .find(|t| t.name == table)
                .ok_or_else(|| {
                    QueryError::SchemaError(format!("Table '{table}' not found in current schema."))
                })?;

            let column_def = table_def
                .columns
                .iter()
                .find(|c| c.name == column)
                .ok_or_else(|| {
                    QueryError::SchemaError(format!(
                        "Column '{column}' not found in table '{table}'."
                    ))
                })?;

            // Build the full column definition with updated comment
            let mut modified_col_def = column_def.clone();
            modified_col_def.comment = new_comment.map(std::string::ToString::to_string);

            // Build base ALTER TABLE statement using sea-query for type/nullable/default
            let sea_col = build_sea_column_def_with_table(backend, table, &modified_col_def);

            // Build the ALTER TABLE ... MODIFY COLUMN statement
            let stmt = sea_query::Table::alter()
                .table(Alias::new(table))
                .modify_column(sea_col)
                .to_owned();

            // Get the base SQL from sea-query
            let base_sql = super::helpers::build_schema_statement(&stmt, backend);

            // Add COMMENT clause if needed (sea-query doesn't support COMMENT)
            let final_sql = if let Some(comment) = modified_col_def.comment.as_deref() {
                let escaped = comment.replace('\'', "''");
                format!("{base_sql} COMMENT '{escaped}'")
            } else {
                base_sql
            };

            queries.push(BuiltQuery::Raw(RawSql::uniform(final_sql)));
        }
        DatabaseBackend::Sqlite => {
            // SQLite doesn't support column comments
            // We could store the comment in a separate table or just ignore it
            // For now, we'll skip this operation for SQLite since it doesn't affect the schema
            // Just update the internal schema representation (handled by apply.rs)
        }
    }

    Ok(queries)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::test_support::col_n as col;
    use insta::{assert_snapshot, with_settings};
    use rstest::rstest;
    use vespertide_core::{ColumnDef, ColumnType, SimpleColumnType, TableConstraint};

    fn table_def(
        name: &str,
        columns: Vec<ColumnDef>,
        constraints: Vec<TableConstraint>,
    ) -> TableDef {
        TableDef {
            name: name.into(),
            description: None,
            columns,
            constraints,
        }
    }

    #[rstest]
    #[case::postgres_set_comment(DatabaseBackend::Postgres, Some("User email address"))]
    #[case::postgres_drop_comment(DatabaseBackend::Postgres, None)]
    #[case::mysql_set_comment(DatabaseBackend::MySql, Some("User email address"))]
    #[case::mysql_drop_comment(DatabaseBackend::MySql, None)]
    #[case::sqlite_set_comment(DatabaseBackend::Sqlite, Some("User email address"))]
    #[case::sqlite_drop_comment(DatabaseBackend::Sqlite, None)]
    fn test_build_modify_column_comment(
        #[case] backend: DatabaseBackend,
        #[case] new_comment: Option<&str>,
    ) {
        let schema = vec![table_def(
            "users",
            vec![
                col("id", ColumnType::Simple(SimpleColumnType::Integer), false),
                col("email", ColumnType::Simple(SimpleColumnType::Text), true),
            ],
            vec![],
        )];

        let result = build_modify_column_comment(backend, "users", "email", new_comment, &schema);
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let suffix = format!(
            "{}_{}_users",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            },
            if new_comment.is_some() {
                "set_comment"
            } else {
                "drop_comment"
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test comment with quotes escaping
    #[rstest]
    #[case::postgres_comment_with_quotes(DatabaseBackend::Postgres)]
    #[case::mysql_comment_with_quotes(DatabaseBackend::MySql)]
    #[case::sqlite_comment_with_quotes(DatabaseBackend::Sqlite)]
    fn test_comment_with_quotes(#[case] backend: DatabaseBackend) {
        let schema = vec![table_def(
            "users",
            vec![col(
                "email",
                ColumnType::Simple(SimpleColumnType::Text),
                true,
            )],
            vec![],
        )];

        let result = build_modify_column_comment(
            backend,
            "users",
            "email",
            Some("User's email address"),
            &schema,
        );
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        // Postgres and MySQL should escape quotes, SQLite returns empty
        if backend != DatabaseBackend::Sqlite {
            assert!(
                sql.contains("User''s email address"),
                "Should escape single quotes"
            );
        }

        let suffix = format!(
            "{}_comment_with_quotes",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test table not found error
    #[rstest]
    #[case::postgres_table_not_found(DatabaseBackend::Postgres)]
    #[case::mysql_table_not_found(DatabaseBackend::MySql)]
    #[case::sqlite_table_not_found(DatabaseBackend::Sqlite)]
    fn test_table_not_found(#[case] backend: DatabaseBackend) {
        // Postgres and SQLite don't need schema lookup, so skip this test for them
        if backend == DatabaseBackend::Postgres || backend == DatabaseBackend::Sqlite {
            return;
        }

        let result = build_modify_column_comment(backend, "users", "email", Some("comment"), &[]);
        assert!(result.is_err());
        let err_msg = result.unwrap_err().to_string();
        assert!(err_msg.contains("Table 'users' not found"));
    }

    /// Test column not found error
    #[rstest]
    #[case::postgres_column_not_found(DatabaseBackend::Postgres)]
    #[case::mysql_column_not_found(DatabaseBackend::MySql)]
    #[case::sqlite_column_not_found(DatabaseBackend::Sqlite)]
    fn test_column_not_found(#[case] backend: DatabaseBackend) {
        // Postgres and SQLite don't need schema lookup, so skip this test for them
        if backend == DatabaseBackend::Postgres || backend == DatabaseBackend::Sqlite {
            return;
        }

        let schema = vec![table_def(
            "users",
            vec![col(
                "id",
                ColumnType::Simple(SimpleColumnType::Integer),
                false,
            )],
            vec![],
        )];

        let result =
            build_modify_column_comment(backend, "users", "email", Some("comment"), &schema);
        assert!(result.is_err());
        let err_msg = result.unwrap_err().to_string();
        assert!(err_msg.contains("Column 'email' not found"));
    }

    /// Test with long comment
    #[rstest]
    #[case::postgres_long_comment(DatabaseBackend::Postgres)]
    #[case::mysql_long_comment(DatabaseBackend::MySql)]
    #[case::sqlite_long_comment(DatabaseBackend::Sqlite)]
    fn test_long_comment(#[case] backend: DatabaseBackend) {
        let schema = vec![table_def(
            "users",
            vec![col("bio", ColumnType::Simple(SimpleColumnType::Text), true)],
            vec![],
        )];

        let long_comment = "This is a very long comment that describes the bio field in great detail. It contains multiple sentences and provides thorough documentation for this column.";

        let result =
            build_modify_column_comment(backend, "users", "bio", Some(long_comment), &schema);
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let suffix = format!(
            "{}_long_comment",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test preserves column properties when modifying comment
    #[rstest]
    #[case::postgres_preserves_properties(DatabaseBackend::Postgres)]
    #[case::mysql_preserves_properties(DatabaseBackend::MySql)]
    #[case::sqlite_preserves_properties(DatabaseBackend::Sqlite)]
    fn test_preserves_column_properties(#[case] backend: DatabaseBackend) {
        let mut email_col = col("email", ColumnType::Simple(SimpleColumnType::Text), true);
        email_col.default = Some("'default@example.com'".into());

        let schema = vec![table_def(
            "users",
            vec![
                col("id", ColumnType::Simple(SimpleColumnType::Integer), false),
                email_col,
            ],
            vec![],
        )];

        let result = build_modify_column_comment(
            backend,
            "users",
            "email",
            Some("User email address"),
            &schema,
        );
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        // MySQL should preserve the default value in the MODIFY COLUMN statement
        if backend == DatabaseBackend::MySql {
            assert!(sql.contains("DEFAULT"), "Should preserve DEFAULT clause");
        }

        let suffix = format!(
            "{}_preserves_properties",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test changing comment from one value to another
    #[rstest]
    #[case::postgres_change_comment(DatabaseBackend::Postgres)]
    #[case::mysql_change_comment(DatabaseBackend::MySql)]
    #[case::sqlite_change_comment(DatabaseBackend::Sqlite)]
    fn test_change_comment(#[case] backend: DatabaseBackend) {
        let mut email_col = col("email", ColumnType::Simple(SimpleColumnType::Text), true);
        email_col.comment = Some("Old comment".into());

        let schema = vec![table_def(
            "users",
            vec![
                col("id", ColumnType::Simple(SimpleColumnType::Integer), false),
                email_col,
            ],
            vec![],
        )];

        let result =
            build_modify_column_comment(backend, "users", "email", Some("New comment"), &schema);
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let suffix = format!(
            "{}_change_comment",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test dropping existing comment
    #[rstest]
    #[case::postgres_drop_existing_comment(DatabaseBackend::Postgres)]
    #[case::mysql_drop_existing_comment(DatabaseBackend::MySql)]
    #[case::sqlite_drop_existing_comment(DatabaseBackend::Sqlite)]
    fn test_drop_existing_comment(#[case] backend: DatabaseBackend) {
        let mut email_col = col("email", ColumnType::Simple(SimpleColumnType::Text), true);
        email_col.comment = Some("Existing comment".into());

        let schema = vec![table_def(
            "users",
            vec![
                col("id", ColumnType::Simple(SimpleColumnType::Integer), false),
                email_col,
            ],
            vec![],
        )];

        let result = build_modify_column_comment(
            backend, "users", "email", None, // Drop comment
            &schema,
        );
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let suffix = format!(
            "{}_drop_existing_comment",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Test with different column types
    #[rstest]
    #[case::postgres_integer_column(
        DatabaseBackend::Postgres,
        SimpleColumnType::Integer,
        "Auto-increment ID"
    )]
    #[case::mysql_integer_column(
        DatabaseBackend::MySql,
        SimpleColumnType::Integer,
        "Auto-increment ID"
    )]
    #[case::sqlite_integer_column(
        DatabaseBackend::Sqlite,
        SimpleColumnType::Integer,
        "Auto-increment ID"
    )]
    #[case::postgres_boolean_column(
        DatabaseBackend::Postgres,
        SimpleColumnType::Boolean,
        "Is user active"
    )]
    #[case::mysql_boolean_column(
        DatabaseBackend::MySql,
        SimpleColumnType::Boolean,
        "Is user active"
    )]
    #[case::sqlite_boolean_column(
        DatabaseBackend::Sqlite,
        SimpleColumnType::Boolean,
        "Is user active"
    )]
    #[case::postgres_timestamp_column(
        DatabaseBackend::Postgres,
        SimpleColumnType::Timestamp,
        "Creation timestamp"
    )]
    #[case::mysql_timestamp_column(
        DatabaseBackend::MySql,
        SimpleColumnType::Timestamp,
        "Creation timestamp"
    )]
    #[case::sqlite_timestamp_column(
        DatabaseBackend::Sqlite,
        SimpleColumnType::Timestamp,
        "Creation timestamp"
    )]
    fn test_comment_on_different_types(
        #[case] backend: DatabaseBackend,
        #[case] column_type: SimpleColumnType,
        #[case] comment: &str,
    ) {
        let schema = vec![table_def(
            "data",
            vec![col("field", ColumnType::Simple(column_type), false)],
            vec![],
        )];

        let result = build_modify_column_comment(backend, "data", "field", Some(comment), &schema);
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let type_name = format!("{column_type:?}").to_lowercase();
        let suffix = format!(
            "{}_{}_comment",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            },
            type_name
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }

    /// Mutant target: `modify_column_comment.rs` line 54 — the MySQL
    /// branch `comment: new_comment.map(...)` plus the surrounding emit
    /// path that hand-appends `COMMENT '...'`. Pins EXACT `'hello'`
    /// literal so any mutation blanking the comment is caught.
    #[rstest]
    #[case::postgres_set(DatabaseBackend::Postgres, Some("hello"))]
    #[case::postgres_drop(DatabaseBackend::Postgres, None)]
    #[case::mysql_set(DatabaseBackend::MySql, Some("hello"))]
    #[case::mysql_drop(DatabaseBackend::MySql, None)]
    #[case::sqlite_set(DatabaseBackend::Sqlite, Some("hello"))]
    #[case::sqlite_drop(DatabaseBackend::Sqlite, None)]
    fn modify_column_comment_emits_exact_literal(
        #[case] backend: DatabaseBackend,
        #[case] new_comment: Option<&str>,
    ) {
        let schema = vec![table_def(
            "users",
            vec![col(
                "email",
                ColumnType::Simple(SimpleColumnType::Text),
                false,
            )],
            vec![],
        )];

        let queries = build_modify_column_comment(backend, "users", "email", new_comment, &schema)
            .expect("build_modify_column_comment should succeed");
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        match (backend, new_comment) {
            (DatabaseBackend::Sqlite, _) => {
                assert!(
                    queries.is_empty(),
                    "SQLite does not support column comments; expected no \
                     emitted SQL, got: {sql}"
                );
            }
            (DatabaseBackend::Postgres, Some(_)) => {
                assert!(
                    sql.contains("IS 'hello'"),
                    "Postgres set-comment must emit exact `IS 'hello'`; got: {sql}"
                );
                assert!(
                    sql.contains("COMMENT ON COLUMN \"users\".\"email\" IS 'hello'"),
                    "Postgres set-comment must emit the full `COMMENT ON \
                     COLUMN \"users\".\"email\" IS 'hello'` statement; got: {sql}"
                );
            }
            (DatabaseBackend::Postgres, None) => {
                assert!(
                    sql.contains("IS NULL"),
                    "Postgres drop-comment must emit exact `IS NULL`; got: {sql}"
                );
                assert!(
                    !sql.contains("IS ''"),
                    "Postgres drop-comment must not emit empty-string literal \
                     `IS ''`; got: {sql}"
                );
            }
            (DatabaseBackend::MySql, Some(_)) => {
                assert!(
                    sql.contains("COMMENT 'hello'"),
                    "MySQL set-comment must emit exact `COMMENT 'hello'`; got: {sql}"
                );
                assert!(
                    !sql.contains("COMMENT ''"),
                    "MySQL set-comment must not emit empty-string literal \
                     `COMMENT ''`; got: {sql}"
                );
                assert!(
                    sql.contains("MODIFY COLUMN"),
                    "MySQL set-comment must use ALTER TABLE ... MODIFY COLUMN; \
                     got: {sql}"
                );
            }
            (DatabaseBackend::MySql, None) => {
                assert!(
                    !sql.contains("COMMENT '"),
                    "MySQL drop-comment must not append any `COMMENT '...'` \
                     clause; got: {sql}"
                );
                assert!(
                    sql.contains("MODIFY COLUMN"),
                    "MySQL drop-comment must still emit MODIFY COLUMN; got: {sql}"
                );
            }
        }
    }

    /// Test with NOT NULL column
    #[rstest]
    #[case::postgres_not_null_column(DatabaseBackend::Postgres)]
    #[case::mysql_not_null_column(DatabaseBackend::MySql)]
    #[case::sqlite_not_null_column(DatabaseBackend::Sqlite)]
    fn test_comment_on_not_null_column(#[case] backend: DatabaseBackend) {
        let schema = vec![table_def(
            "users",
            vec![col(
                "username",
                ColumnType::Simple(SimpleColumnType::Text),
                false,
            )],
            vec![],
        )];

        let result = build_modify_column_comment(
            backend,
            "users",
            "username",
            Some("Required username"),
            &schema,
        );
        assert!(result.is_ok());
        let queries = result.unwrap();
        let sql = queries
            .iter()
            .map(|q| q.build(backend))
            .collect::<Vec<String>>()
            .join("\n");

        let suffix = format!(
            "{}_not_null_column",
            match backend {
                DatabaseBackend::Postgres => "postgres",
                DatabaseBackend::MySql => "mysql",
                DatabaseBackend::Sqlite => "sqlite",
            }
        );

        with_settings!({ snapshot_suffix => suffix }, {
            assert_snapshot!(sql);
        });
    }
}