use crate::utils::add_value_to_map;
use crate::webserver::database::blob_to_data_url;
use bigdecimal::BigDecimal;
use chrono::{DateTime, FixedOffset, NaiveDate, NaiveDateTime};
use serde_json::{self, Map, Value};
use sqlx::any::{AnyColumn, AnyRow, AnyTypeInfo, AnyTypeInfoKind};
use sqlx::postgres::PgValueRef;
use sqlx::postgres::types::PgRange;
use sqlx::{Column, Row, TypeInfo, ValueRef};
use sqlx::{Decode, Type};

pub fn row_to_json(row: &AnyRow) -> Value {
    use Value::Object;

    let columns = row.columns();
    let mut map = Map::new();
    for col in columns {
        let key = canonical_col_name(col);
        let value: Value = sql_to_json(row, col);
        map = add_value_to_map(map, (key, value));
    }
    Object(map)
}

fn canonical_col_name(col: &AnyColumn) -> String {
    // Some databases fold all unquoted identifiers to uppercase but SQLPage uses lowercase property names
    if matches!(col.type_info().0, AnyTypeInfoKind::Odbc(_))
        && col
            .name()
            .chars()
            .all(|c| c.is_ascii_uppercase() || c == '_')
    {
        col.name().to_ascii_lowercase()
    } else {
        col.name().to_owned()
    }
}

pub fn sql_to_json(row: &AnyRow, col: &sqlx::any::AnyColumn) -> Value {
    let raw_value_result = row.try_get_raw(col.ordinal());
    match raw_value_result {
        Ok(raw_value) if !raw_value.is_null() => {
            let mut raw_value = Some(raw_value);
            let decoded = sql_nonnull_to_json(|| {
                raw_value
                    .take()
                    .unwrap_or_else(|| row.try_get_raw(col.ordinal()).unwrap())
            });
            log::trace!("Decoded value: {decoded:?}");
            decoded
        }
        Ok(_null) => Value::Null,
        Err(e) => {
            log::warn!("Unable to extract value from row: {e:?}");
            Value::Null
        }
    }
}

fn decode_raw<'a, T: Decode<'a, sqlx::any::Any> + Default>(
    raw_value: sqlx::any::AnyValueRef<'a>,
) -> T {
    match T::decode(raw_value) {
        Ok(v) => v,
        Err(e) => {
            let type_name = std::any::type_name::<T>();
            log::error!("Failed to decode {type_name} value: {e}");
            T::default()
        }
    }
}

fn decode_pg_range<'r, T>(raw_value: sqlx::any::AnyValueRef<'r>) -> Value
where
    T: std::fmt::Display
        + Type<sqlx::postgres::Postgres>
        + for<'a> sqlx::Decode<'a, sqlx::postgres::Postgres>,
{
    let Ok(pg_val): Result<PgValueRef<'r>, _> = raw_value.try_into() else {
        log::error!("Only postgres range values are supported");
        return Value::Null;
    };
    match <PgRange<T> as sqlx::Decode<'r, sqlx::postgres::Postgres>>::decode(pg_val) {
        Ok(pg_range) => pg_range.to_string().into(),
        Err(e) => {
            log::error!("Failed to decode postgres range value: {e}");
            Value::Null
        }
    }
}

fn decimal_to_json(decimal: &BigDecimal) -> Value {
    // to_plain_string always returns a valid JSON string
    Value::Number(serde_json::Number::from_string_unchecked(
        decimal.normalized().to_plain_string(),
    ))
}

pub fn sql_nonnull_to_json<'r>(mut get_ref: impl FnMut() -> sqlx::any::AnyValueRef<'r>) -> Value {
    use AnyTypeInfoKind::{Mssql, MySql};
    let raw_value = get_ref();
    let type_info = raw_value.type_info();
    let type_name = type_info.name();
    log::trace!("Decoding a value of type {type_name:?} (type info: {type_info:?})");
    let AnyTypeInfo(ref db_type) = *type_info;
    match type_name {
        "REAL" | "FLOAT" | "FLOAT4" | "FLOAT8" | "DOUBLE" => decode_raw::<f64>(raw_value).into(),
        "NUMERIC" | "DECIMAL" => decimal_to_json(&decode_raw(raw_value)),
        "INT8" | "BIGINT" | "SERIAL8" | "BIGSERIAL" | "IDENTITY" | "INT64" | "INTEGER8"
        | "BIGINT SIGNED" => decode_raw::<i64>(raw_value).into(),
        "INT" | "INT4" | "INTEGER" | "MEDIUMINT" | "YEAR" => decode_raw::<i32>(raw_value).into(),
        "INT2" | "SMALLINT" | "TINYINT" => decode_raw::<i16>(raw_value).into(),
        "BIGINT UNSIGNED" => decode_raw::<u64>(raw_value).into(),
        "INT UNSIGNED" | "MEDIUMINT UNSIGNED" | "SMALLINT UNSIGNED" | "TINYINT UNSIGNED" => {
            decode_raw::<u32>(raw_value).into()
        }
        "BOOL" | "BOOLEAN" => decode_raw::<bool>(raw_value).into(),
        "BIT" if matches!(db_type, Mssql(_)) => decode_raw::<bool>(raw_value).into(),
        "BIT" if matches!(db_type, MySql(mysql_type) if mysql_type.max_size() == Some(1)) => {
            decode_raw::<bool>(raw_value).into()
        }
        "BIT" if matches!(db_type, MySql(_)) => decode_raw::<u64>(raw_value).into(),
        "DATE" => decode_raw::<chrono::NaiveDate>(raw_value)
            .to_string()
            .into(),
        "TIME" | "TIMETZ" => decode_raw::<chrono::NaiveTime>(raw_value)
            .to_string()
            .into(),
        "DATETIMEOFFSET" | "TIMESTAMP" | "TIMESTAMPTZ" => {
            decode_raw::<DateTime<FixedOffset>>(raw_value)
                .to_rfc3339()
                .into()
        }
        "DATETIME" | "DATETIME2" => decode_raw::<NaiveDateTime>(raw_value)
            .format("%FT%T%.f")
            .to_string()
            .into(),
        "MONEY" | "SMALLMONEY" if matches!(db_type, Mssql(_)) => {
            decode_raw::<f64>(raw_value).into()
        }
        "UUID" | "UNIQUEIDENTIFIER" => decode_raw::<sqlx::types::uuid::Uuid>(raw_value)
            .to_string()
            .into(),
        "JSON" | "JSON[]" | "JSONB" | "JSONB[]" => decode_raw::<Value>(raw_value),
        "BLOB" | "BYTEA" | "FILESTREAM" | "VARBINARY" | "BIGVARBINARY" | "BINARY" | "IMAGE" => {
            blob_to_data_url::vec_to_data_uri_value(&decode_raw::<Vec<u8>>(raw_value))
        }
        "INT4RANGE" => decode_pg_range::<i32>(raw_value),
        "INT8RANGE" => decode_pg_range::<i64>(raw_value),
        "NUMRANGE" => decode_pg_range::<BigDecimal>(raw_value),
        "DATERANGE" => decode_pg_range::<NaiveDate>(raw_value),
        "TSRANGE" => decode_pg_range::<NaiveDateTime>(raw_value),
        "TSTZRANGE" => decode_pg_range::<DateTime<FixedOffset>>(raw_value),
        // Deserialize as a string by default
        _ => decode_raw::<String>(raw_value).into(),
    }
}

/// Takes the first column of a row and converts it to a string.
pub fn row_to_string(row: &AnyRow) -> Option<String> {
    let col = row.columns().first()?;
    match sql_to_json(row, col) {
        serde_json::Value::String(s) => Some(s),
        serde_json::Value::Null => None,
        other => Some(other.to_string()),
    }
}

#[cfg(test)]
mod tests {
    use crate::app_config::tests::test_database_url;

    use super::*;
    use sqlx::Connection;

    fn setup_logging() {
        crate::telemetry::init_test_logging();
    }

    fn db_specific_test(db_type: &str) -> Option<String> {
        setup_logging();
        let db_url = test_database_url();
        if db_url.starts_with(db_type) {
            Some(db_url)
        } else {
            log::warn!("Skipping test because DATABASE_URL is not set to a {db_type} database");
            None
        }
    }

    #[actix_web::test]
    async fn test_row_to_json() -> anyhow::Result<()> {
        use sqlx::Connection;
        let db_url = test_database_url();
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                123.456 as one_value,
                1 as two_values,
                2 as two_values,
                'x' as three_values,
                'y' as three_values,
                'z' as three_values
        ",
        )
        .fetch_one(&mut c)
        .await?;
        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "one_value": 123.456,
                "two_values": [1,2],
                "three_values": ["x","y","z"],
            }),
        );
        Ok(())
    }

    #[actix_web::test]
    async fn test_postgres_types() -> anyhow::Result<()> {
        let Some(db_url) = db_specific_test("postgres") else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                42::INT2 as small_int,
                42::INT4 as integer,
                42::INT8 as big_int,
                42.25::FLOAT4 as float4,
                42.25::FLOAT8 as float8,
                123456789123456789123456789::NUMERIC as numeric,
                TRUE as boolean,
                '2024-03-14'::DATE as date,
                '13:14:15'::TIME as time,
                '2024-03-14 13:14:15'::TIMESTAMP as timestamp,
                '2024-03-14 13:14:15+02:00'::TIMESTAMPTZ as timestamptz,
                INTERVAL '1 year 2 months 3 days' as complex_interval,
                INTERVAL '4 hours' as hour_interval,
                INTERVAL '1.5 days' as fractional_interval,
                '{\"key\": \"value\"}'::JSON as json,
                '{\"key\": \"value\"}'::JSONB as jsonb,
                age('2024-03-14'::timestamp, '2024-01-01'::timestamp) as age_interval,
                justify_interval(interval '1 year 2 months 3 days') as justified_interval,
                1234.56::MONEY as money_val,
                '\\x68656c6c6f20776f726c64'::BYTEA as blob_data,
                '550e8400-e29b-41d4-a716-446655440000'::UUID as uuid,
                '[1,5)'::INT4RANGE as int4range,
                '[1,5]'::INT8RANGE as int8range,
                '[1.5,4.5)'::NUMRANGE as numrange,
                -- '[2024-11-12 01:02:03,2024-11-12 23:00:00)'::TSRANGE as tsrange,
                -- '[2024-11-12 01:02:03+01:00,2024-11-12 23:00:00+00:00)'::TSTZRANGE as tstzrange,
                '[2024-11-12,2024-11-13)'::DATERANGE as daterange
            ",
        )
        .fetch_one(&mut c)
        .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "small_int": 42,
                "integer": 42,
                "big_int": 42,
                "float4": 42.25,
                "float8": 42.25,
                "numeric": 123_456_789_123_456_789_123_456_789_u128,
                "boolean": true,
                "date": "2024-03-14",
                "time": "13:14:15",
                "timestamp": "2024-03-14T13:14:15+00:00",
                "timestamptz": "2024-03-14T11:14:15+00:00",
                "complex_interval": "1 year 2 mons 3 days",
                "hour_interval": "04:00:00",
                "fractional_interval": "1 day 12:00:00",
                "json": {"key": "value"},
                "jsonb": {"key": "value"},
                "age_interval": "2 mons 13 days",
                "justified_interval": "1 year 2 mons 3 days",
                "money_val": "$1,234.56",
                "blob_data": "data:application/octet-stream;base64,aGVsbG8gd29ybGQ=",
                "uuid": "550e8400-e29b-41d4-a716-446655440000",
                "int4range": "[1,5)",
                "int8range": "[1,6)",
                "numrange": "[1.5,4.5)",
                //"tsrange": "[2024-11-12 01:02:03,2024-11-12 23:00:00)", // todo: bug in sqlx datetime range parsing
                //"tstzrange": "[\"2024-11-12 02:00:00 +01:00\",\"2024-11-12 23:00:00 +00:00\")", // todo: tz info is lost in sqlx
                "daterange": "[2024-11-12,2024-11-13)"
            }),
        );
        Ok(())
    }

    /// Postgres encodes values differently in prepared statements and in "simple" queries
    /// <https://www.postgresql.org/docs/9.1/protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY>
    #[actix_web::test]
    async fn test_postgres_prepared_types() -> anyhow::Result<()> {
        let Some(db_url) = db_specific_test("postgres") else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                '2024-03-14'::DATE as date,
                '13:14:15'::TIME as time,
                '2024-03-14 13:14:15+02:00'::TIMESTAMPTZ as timestamptz,
                INTERVAL '-01:02:03' as time_interval,
                '{\"key\": \"value\"}'::JSON as json,
                1234.56::MONEY as money_val,
                '\\x74657374'::BYTEA as blob_data,
                '550e8400-e29b-41d4-a716-446655440000'::UUID as uuid
            where $1",
        )
        .bind(true)
        .fetch_one(&mut c)
        .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "date": "2024-03-14",
                "time": "13:14:15",
                "timestamptz": "2024-03-14T11:14:15+00:00",
                "time_interval": "-01:02:03",
                "json": {"key": "value"},
                "money_val": "", // TODO: fix this bug: https://github.com/sqlpage/SQLPage/issues/983
                "blob_data": "data:application/octet-stream;base64,dGVzdA==",
                "uuid": "550e8400-e29b-41d4-a716-446655440000",
            }),
        );
        Ok(())
    }

    #[actix_web::test]
    async fn test_postgres_prepared_range_types() -> anyhow::Result<()> {
        let Some(db_url) = db_specific_test("postgres") else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                '[1,5)'::INT4RANGE as int4range,
                '[2024-11-12 01:02:03,2024-11-12 23:00:00)'::TSRANGE as tsrange,
                '[2024-11-12 01:02:03+01:00,2024-11-12 23:00:00+00:00)'::TSTZRANGE as tstzrange,
                '[2024-11-12,2024-11-13)'::DATERANGE as daterange
            where $1",
        )
        .bind(true)
        .fetch_one(&mut c)
        .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "int4range": "[1,5)",
                "tsrange": "[2024-11-12 01:02:03,2024-11-12 23:00:00)",
                "tstzrange": "[2024-11-12 00:02:03 +00:00,2024-11-12 23:00:00 +00:00)", // todo: tz info is lost in sqlx
                "daterange": "[2024-11-12,2024-11-13)"
            }),
        );
        Ok(())
    }

    #[actix_web::test]
    async fn test_mysql_types() -> anyhow::Result<()> {
        let db_url = db_specific_test("mysql").or_else(|| db_specific_test("mariadb"));
        let Some(db_url) = db_url else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;

        sqlx::query(
            "CREATE TEMPORARY TABLE _sqlp_t (
                tiny_int TINYINT,
                small_int SMALLINT,
                medium_int MEDIUMINT,
                signed_int INTEGER,
                big_int BIGINT,
                unsigned_int INTEGER UNSIGNED,
                tiny_int_unsigned TINYINT UNSIGNED,
                small_int_unsigned SMALLINT UNSIGNED,
                medium_int_unsigned MEDIUMINT UNSIGNED,
                big_int_unsigned BIGINT UNSIGNED,
                decimal_num DECIMAL(10,2),
                float_num FLOAT,
                double_num DOUBLE,
                bit_val BIT(1),
                date_val DATE,
                time_val TIME,
                datetime_val DATETIME,
                timestamp_val TIMESTAMP,
                year_val YEAR,
                char_val CHAR(10),
                varchar_val VARCHAR(50),
                text_val TEXT,
                blob_val BLOB
            ) AS
            SELECT
                127 as tiny_int,
                32767 as small_int,
                8388607 as medium_int,
                -1000000 as signed_int,
                9223372036854775807 as big_int,
                1000000 as unsigned_int,
                255 as tiny_int_unsigned,
                65535 as small_int_unsigned,
                16777215 as medium_int_unsigned,
                18446744073709551615 as big_int_unsigned,
                123.45 as decimal_num,
                42.25 as float_num,
                42.25 as double_num,
                1 as bit_val,
                '2024-03-14' as date_val,
                '13:14:15' as time_val,
                '2024-03-14 13:14:15' as datetime_val,
                '2024-03-14 13:14:15' as timestamp_val,
                2024 as year_val,
                'CHAR' as char_val,
                'VARCHAR' as varchar_val,
                'TEXT' as text_val,
                x'626c6f62' as blob_val",
        )
        .execute(&mut c)
        .await?;

        let row = sqlx::query("SELECT * FROM _sqlp_t")
            .fetch_one(&mut c)
            .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "tiny_int": 127,
                "small_int": 32767,
                "medium_int": 8_388_607,
                "signed_int": -1_000_000,
                "big_int": 9_223_372_036_854_775_807_u64,
                "unsigned_int": 1_000_000,
                "tiny_int_unsigned": 255,
                "small_int_unsigned": 65_535,
                "medium_int_unsigned": 16_777_215,
                "big_int_unsigned": 18_446_744_073_709_551_615_u64,
                "decimal_num": 123.45,
                "float_num": 42.25,
                "double_num": 42.25,
                "bit_val": true,
                "date_val": "2024-03-14",
                "time_val": "13:14:15",
                "datetime_val": "2024-03-14T13:14:15",
                "timestamp_val": "2024-03-14T13:14:15+00:00",
                "year_val": 2024,
                "char_val": "CHAR",
                "varchar_val": "VARCHAR",
                "text_val": "TEXT",
                "blob_val": "data:application/octet-stream;base64,YmxvYg=="
            }),
        );

        sqlx::query("DROP TABLE _sqlp_t").execute(&mut c).await?;

        Ok(())
    }

    #[actix_web::test]
    async fn test_sqlite_types() -> anyhow::Result<()> {
        let Some(db_url) = db_specific_test("sqlite") else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                42 as integer,
                42.25 as real,
                'xxx' as string,
                x'68656c6c6f20776f726c64' as blob",
        )
        .fetch_one(&mut c)
        .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "integer": 42,
                "real": 42.25,
                "string": "xxx",
                "blob": "data:application/octet-stream;base64,aGVsbG8gd29ybGQ=",
            }),
        );
        Ok(())
    }

    #[actix_web::test]
    async fn test_mssql_types() -> anyhow::Result<()> {
        let Some(db_url) = db_specific_test("mssql") else {
            return Ok(());
        };
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let row = sqlx::query(
            "SELECT
                CAST(1 AS BIT) as true_bit,
                CAST(0 AS BIT) as false_bit,
                CAST(NULL AS BIT) as null_bit,
                CAST(255 AS TINYINT) as tiny_int,
                CAST(42 AS SMALLINT) as small_int,
                CAST(42 AS INT) as integer,
                CAST(42 AS BIGINT) as big_int,
                CAST(42.25 AS REAL) as real,
                CAST(42.25 AS FLOAT) as float,
                CAST(42.25 AS DECIMAL(10,2)) as decimal,
                CAST('2024-03-14' AS DATE) as date,
                CAST('13:14:15' AS TIME) as time,
                CAST('2024-03-14 13:14:15' AS DATETIME) as datetime,
                CAST('2024-03-14 13:14:15' AS DATETIME2) as datetime2,
                CAST('2024-03-14 13:14:15 +02:00' AS DATETIMEOFFSET) as datetimeoffset,
                N'Unicode String' as nvarchar,
                'ASCII String' as varchar,
                CAST(1234.56 AS MONEY) as money_val,
                CAST(12.34 AS SMALLMONEY) as small_money_val,
                CAST(0x6D7373716C AS VARBINARY(10)) as blob_data,
                CONVERT(UNIQUEIDENTIFIER, '6F9619FF-8B86-D011-B42D-00C04FC964FF') as unique_identifier
            "
        )
        .fetch_one(&mut c)
        .await?;

        expect_json_object_equal(
            &row_to_json(&row),
            &serde_json::json!({
                "true_bit": true,
                "false_bit": false,
                "null_bit": null,
                "tiny_int": 255,
                "small_int": 42,
                "integer": 42,
                "big_int": 42,
                "real": 42.25,
                "float": 42.25,
                "decimal": 42.25,
                "date": "2024-03-14",
                "time": "13:14:15",
                "datetime": "2024-03-14T13:14:15",
                "datetime2": "2024-03-14T13:14:15",
                "datetimeoffset": "2024-03-14T13:14:15+02:00",
                "nvarchar": "Unicode String",
                "varchar": "ASCII String",
                "money_val": 1234.56,
                "small_money_val": 12.34,
                "blob_data": "data:application/octet-stream;base64,bXNzcWw=",
                "unique_identifier": "6f9619ff-8b86-d011-b42d-00c04fc964ff"
            }),
        );
        Ok(())
    }

    fn expect_json_object_equal(actual: &Value, expected: &Value) {
        use std::fmt::Write;

        if json_values_equal(actual, expected) {
            return;
        }
        let actual = actual.as_object().unwrap();
        let expected = expected.as_object().unwrap();

        let all_keys: std::collections::BTreeSet<_> =
            actual.keys().chain(expected.keys()).collect();
        let max_key_len = all_keys.iter().map(|k| k.len()).max().unwrap_or(0);

        let mut comparison_string = String::new();
        for key in all_keys {
            let actual_value = actual.get(key).unwrap_or(&Value::Null);
            let expected_value = expected.get(key).unwrap_or(&Value::Null);
            if json_values_equal(actual_value, expected_value) {
                continue;
            }
            writeln!(
                &mut comparison_string,
                "{key:<max_key_len$}  actual  : {actual_value:?}\n{key:max_key_len$}  expected: {expected_value:?}\n"
            )
            .unwrap();
        }
        assert_eq!(
            actual, expected,
            "JSON objects are not equal:\n\n{comparison_string}"
        );
    }

    #[actix_web::test]
    async fn test_canonical_col_name_variations() -> anyhow::Result<()> {
        let db_url = test_database_url();
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;

        // Test various column name formats to ensure canonical_col_name works correctly
        let row = sqlx::query(
            r#"SELECT
                42 as "UPPERCASE_COL",
                42 as "lowercase_col",
                42 as "Mixed_Case_Col",
                42 as "COL_WITH_123_NUMBERS",
                42 as "col-with-dashes",
                42 as "col with spaces",
                42 as "_UNDERSCORE_PREFIX",
                42 as "123_NUMBER_PREFIX"
        "#,
        )
        .fetch_one(&mut c)
        .await?;

        let json_result = row_to_json(&row);

        // For ODBC databases, uppercase columns should be converted to lowercase
        // For other databases, names should remain as-is
        let expected_json = if c.kind() == sqlx::any::AnyKind::Odbc {
            // ODBC database - uppercase should be converted to lowercase
            serde_json::json!({
                "uppercase_col": 42,
                "lowercase_col": 42,
                "Mixed_Case_Col": 42,
                "COL_WITH_123_NUMBERS": 42,
                "col-with-dashes": 42,
                "col with spaces": 42,
                "_underscore_prefix": 42,
                "123_NUMBER_PREFIX": 42
            })
        } else {
            // Non-ODBC database - names remain as-is
            serde_json::json!({
                "UPPERCASE_COL": 42,
                "lowercase_col": 42,
                "Mixed_Case_Col": 42,
                "COL_WITH_123_NUMBERS": 42,
                "col-with-dashes": 42,
                "col with spaces": 42,
                "_UNDERSCORE_PREFIX": 42,
                "123_NUMBER_PREFIX": 42
            })
        };

        expect_json_object_equal(&json_result, &expected_json);

        Ok(())
    }

    #[actix_web::test]
    async fn test_row_to_json_edge_cases() -> anyhow::Result<()> {
        let db_url = test_database_url();
        let mut c = sqlx::AnyConnection::connect(&db_url).await?;
        let dbms_name = c.dbms_name().await.expect("retrieve db name");

        // Test edge cases for row_to_json
        let row = sqlx::query(
            "SELECT
                NULL as null_col,
                '' as empty_string,
                0 as zero_value,
                -42 as negative_int,
                1.23456 as my_float,
                'special_chars_!@#$%^&*()' as special_chars,
                'line1
line2' as multiline_string
        ",
        )
        .fetch_one(&mut c)
        .await?;

        let json_result = row_to_json(&row);

        // For Oracle databases, empty string is treated as NULL.
        let empty_str_is_null = dbms_name.to_lowercase().contains("oracle");

        let expected_json = serde_json::json!({
            "null_col": null,
            "empty_string": if empty_str_is_null { serde_json::Value::Null } else { serde_json::Value::String(String::new()) },
            "zero_value": 0,
            "negative_int": -42,
            "my_float": 1.23456,
            "special_chars": "special_chars_!@#$%^&*()",
            "multiline_string": "line1\nline2"
        });

        expect_json_object_equal(&json_result, &expected_json);

        Ok(())
    }

    /// Compare JSON values, treating integers and floats that are numerically equal as equal
    fn json_values_equal(a: &Value, b: &Value) -> bool {
        use Value::*;

        match (a, b) {
            (Null, Null) => true,
            (Bool(a), Bool(b)) => a == b,
            (Number(a), Number(b)) => {
                // Treat integers and floats as equal if they represent the same numerical value
                a.as_f64() == b.as_f64()
            }
            (String(a), String(b)) => a == b,
            (Array(a), Array(b)) => {
                a.len() == b.len() && a.iter().zip(b.iter()).all(|(a, b)| json_values_equal(a, b))
            }
            (Object(a), Object(b)) => {
                if a.len() != b.len() {
                    return false;
                }
                a.iter().all(|(key, value)| {
                    b.get(key)
                        .is_some_and(|expected_value| json_values_equal(value, expected_value))
                })
            }
            _ => false,
        }
    }
}
