sz-orm-core 1.1.0

//! Diesel 风格 schema.rs 自动生成
//!
//! 从数据库表元数据生成 `typed_query!` 表声明，配合宏做编译期列名校验。
//!
//! # 设计
//!
//! Diesel 的 `diesel print-schema` 命令从数据库反向生成 `schema.rs` 文件，
//! 包含 `table!` 宏声明，让 SQL 列名错误在编译期被捕获。
//!
//! 本模块提供等价功能，生成 SZ-ORM 的 `typed_query!` 声明：
//!
//! ```ignore
//! // 生成的 schema.rs 内容
//! use sz_orm_core::typed_query;
//!
//! typed_query! {
//!     table users {
//!         id: i64,
//!         name: String,
//!         email: String,
//!         created_at: String,
//!     }
//! }
//!
//! typed_query! {
//!     table orders {
//!         order_id: i64,
//!         user_id: i64,
//!         total: f64,
//!     }
//! }
//! ```

use std::fmt::Write as _;

/// 单列的元数据（足够生成 typed_query! 声明）
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ColumnSchema {
    /// 列名
    pub name: String,
    /// Rust 类型名（如 "i64"、"String"、"f64"、"`Option<String>`"）
    pub rust_type: String,
}

/// 单表的元数据
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct TableSchema {
    /// 表名
    pub name: String,
    /// 所有列
    pub columns: Vec<ColumnSchema>,
}

/// 生成器：把表元数据列表转换成 schema.rs 文件内容
pub struct SchemaGenerator {
    /// 文件头注释（默认包含 SZ-ORM 自动生成提示）
    header: String,
    /// 是否生成 `use` 语句
    emit_use: bool,
    /// #41 修复：是否同时生成 Model struct 定义
    ///
    /// 启用后，会在 typed_query! 声明之前生成对应的 Rust struct 定义，
    /// 便于用户直接作为 ORM 模型使用，避免手写重复代码。
    emit_model_structs: bool,
    /// #41 修复：生成的 Model struct 的派生属性
    ///
    /// 默认派生 `Debug, Clone, serde::Serialize, serde::Deserialize`，
    /// 用户可通过 [`with_model_derives`](SchemaGenerator::with_model_derives) 自定义。
    model_derives: String,
}

impl Default for SchemaGenerator {
    fn default() -> Self {
        Self::new()
    }
}

impl SchemaGenerator {
    /// 创建新的生成器
    pub fn new() -> Self {
        Self {
            header: format!(
                "// Auto-generated by sz-orm-cli generate schema at {}\n\
                 // DO NOT EDIT MANUALLY — re-run the command to refresh.\n\
                 //\n\
                 // This file contains typed_query! table declarations\n\
                 // enabling compile-time column-name verification.\n",
                chrono::Utc::now().format("%Y-%m-%d %H:%M:%S UTC")
            ),
            emit_use: true,
            emit_model_structs: false,
            model_derives: "Debug, Clone, serde::Serialize, serde::Deserialize".to_string(),
        }
    }

    /// 自定义文件头注释
    pub fn with_header(mut self, header: impl Into<String>) -> Self {
        self.header = header.into();
        self
    }

    /// 是否生成 `use sz_orm_core::typed_query;` 语句
    pub fn emit_use(mut self, emit: bool) -> Self {
        self.emit_use = emit;
        self
    }

    /// #41 修复：是否同时生成 Model struct 定义
    ///
    /// 启用后，[`generate`](Self::generate) 会在 typed_query! 声明之前
    /// 生成对应的 Rust struct 定义，便于直接作为 ORM 模型使用。
    ///
    /// # 示例
    ///
    /// 对于 `users` 表（包含 `id: i64`, `name: String`），会生成：
    ///
    /// ```ignore
    /// #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
    /// pub struct Users {
    ///     pub id: i64,
    ///     pub name: String,
    /// }
    /// ```
    pub fn emit_model_structs(mut self, emit: bool) -> Self {
        self.emit_model_structs = emit;
        self
    }

    /// #41 修复：自定义 Model struct 的派生属性
    ///
    /// 默认为 `"Debug, Clone, serde::Serialize, serde::Deserialize"`。
    /// 传入空字符串则不生成 `#[derive(...)]` 属性。
    pub fn with_model_derives(mut self, derives: impl Into<String>) -> Self {
        self.model_derives = derives.into();
        self
    }

    /// 生成完整的 schema.rs 文件内容
    pub fn generate(&self, tables: &[TableSchema]) -> String {
        let mut out = String::new();

        // 文件头
        writeln!(out, "{}", self.header).expect("write to String is infallible");
        writeln!(out).expect("write to String is infallible");

        // use 语句
        if self.emit_use {
            writeln!(out, "use sz_orm_core::typed_query;").expect("write to String is infallible");
            // 启用 Model struct 生成时，补充 serde 派生所需的 use 语句
            // 合并嵌套 if 为单层 if（clippy::collapsible_if）
            if self.emit_model_structs
                && !self.model_derives.is_empty()
                && self.model_derives.contains("serde::")
            {
                writeln!(out, "use serde::{{Serialize, Deserialize}};")
                    .expect("write to String is infallible");
            }
            writeln!(out).expect("write to String is infallible");
        }

        // #41 修复：先生成 Model struct 定义（在 typed_query! 之前）
        if self.emit_model_structs {
            for (idx, table) in tables.iter().enumerate() {
                if idx > 0 {
                    writeln!(out).expect("write to String is infallible");
                }
                write!(out, "{}", self.render_model_struct(table))
                    .expect("write to String is infallible");
            }
            // Model struct 与 typed_query! 之间空一行
            if !tables.is_empty() {
                writeln!(out).expect("write to String is infallible");
                writeln!(out).expect("write to String is infallible");
            }
        }

        // 每张表生成一个 typed_query! 声明
        for (idx, table) in tables.iter().enumerate() {
            if idx > 0 {
                writeln!(out).expect("write to String is infallible");
            }
            write!(out, "{}", self.render_table(table)).expect("write to String is infallible");
        }

        out
    }

    /// 渲染单张表的 typed_query! 声明
    fn render_table(&self, table: &TableSchema) -> String {
        let mut out = String::new();
        writeln!(out, "typed_query! {{").expect("write to String is infallible");
        writeln!(out, "    table {} {{", table.name).expect("write to String is infallible");
        for col in &table.columns {
            writeln!(out, "        {}: {},", col.name, col.rust_type)
                .expect("write to String is infallible");
        }
        writeln!(out, "    }}").expect("write to String is infallible");
        writeln!(out, "}}").expect("write to String is infallible");
        out
    }

    /// #41 修复：渲染单张表对应的 Model struct 定义
    ///
    /// 将表名转换为 PascalCase 作为 struct 名（如 `users` → `Users`），
    /// 字段名保持 snake_case（符合 Rust 命名约定）。
    fn render_model_struct(&self, table: &TableSchema) -> String {
        let struct_name = to_pascal_case(&table.name);
        let mut out = String::new();
        // 派生属性
        if !self.model_derives.is_empty() {
            writeln!(out, "#[derive({})]", self.model_derives)
                .expect("write to String is infallible");
        }
        // 表名注解（便于 ORM 框架映射到具体表）
        writeln!(out, "#[table_name = \"{}\"]", table.name).expect("write to String is infallible");
        writeln!(out, "pub struct {} {{", struct_name).expect("write to String is infallible");
        for col in &table.columns {
            writeln!(out, "    pub {}: {},", col.name, col.rust_type)
                .expect("write to String is infallible");
        }
        writeln!(out, "}}").expect("write to String is infallible");
        out
    }
}

/// #41 修复：将 snake_case 或 kebab-case 字符串转换为 PascalCase
///
/// 例如：`users` → `Users`，`order_items` → `OrderItems`，
/// `user-profile` → `UserProfile`。
fn to_pascal_case(input: &str) -> String {
    let mut result = String::with_capacity(input.len());
    let mut next_upper = true;
    for ch in input.chars() {
        if ch == '_' || ch == '-' || ch == ' ' {
            next_upper = true;
            continue;
        }
        if next_upper {
            result.push(ch.to_ascii_uppercase());
            next_upper = false;
        } else {
            result.push(ch);
        }
    }
    result
}

/// 把 SQL 类型字符串映射到 Rust 类型字符串
///
/// 用于 `generate schema` 命令从 DB 元数据生成 typed_query! 声明
///
/// # P0 修复：精确匹配
///
/// 旧实现使用 `String::contains` 进行子串匹配，存在以下误判：
/// - `INTERVAL` 含 `int` 子串 → 误判为 `i32`（应为 `String`）
/// - `TIMESTAMP` 含 `time` 子串 → 虽因顺序问题未触发，但逻辑脆弱
/// - `MEDIUMINT` 含 `int` → 正确但依赖匹配顺序，不可靠
///
/// 新实现：
/// 1. 小写化
/// 2. 剥离参数列表（`DECIMAL(10,2)` → `decimal`、`VARCHAR(255)` → `varchar`）
/// 3. 剥离无符号/零填充后缀（`INT UNSIGNED` → `int`、`INT ZEROFILL` → `int`）
/// 4. 精确匹配基础类型名，杜绝子串误判
pub fn sql_type_to_rust(sql_type: &str, nullable: bool) -> String {
    // 1. 小写化
    let lower = sql_type.to_lowercase();
    // 2. 剥离参数列表: "DECIMAL(10,2)" → "decimal", "VARCHAR(255)" → "varchar"
    let after_param_strip = lower.split('(').next().unwrap_or(&lower).trim();
    // 3. 剥离无符号/零填充后缀: "INT UNSIGNED" → "INT", "INT ZEROFILL" → "INT"
    //    仅剥离 " unsigned" 与 " zerofill" 后缀，不影响其他类型
    let base_type = after_param_strip
        .strip_suffix(" unsigned")
        .or_else(|| after_param_strip.strip_suffix(" zerofill"))
        .unwrap_or(after_param_strip)
        .trim();

    let rust = match base_type {
        // 整数 — 精确匹配，避免 "interval" 误匹配 "int"
        "tinyint" => "i8",
        "smallint" | "int2" | "smallserial" => "i16",
        "bigint" | "int8" | "bigserial" => "i64",
        "int" | "integer" | "int4" | "mediumint" | "serial" => "i32",
        // 浮点 — "double precision" 需在 "double" 之前匹配（match 按字面顺序，已显式列出）
        "float8" | "double" | "double precision" => "f64",
        "float4" | "real" | "float" => "f32",
        "decimal" | "numeric" => "f64",
        // 布尔
        "bool" | "boolean" => "bool",
        // 字节
        "blob" | "bytea" | "binary" | "varbinary" | "tinyblob" | "mediumblob" | "longblob" => {
            "Vec<u8>"
        }
        // 时间 — interval 单独匹配，不再被 int 子串误判
        "date" => "String",
        "datetime" | "timestamp" | "timestamptz" => "String",
        "time" | "timetz" => "String",
        "interval" => "String",
        // JSON
        "json" | "jsonb" => "String",
        // UUID
        "uuid" => "String",
        // 字符串
        "char" | "varchar" | "text" | "tinytext" | "mediumtext" | "longtext" => "String",
        "enum" | "set" => "String",
        // 默认
        _ => "String",
    };

    if nullable {
        format!("Option<{}>", rust)
    } else {
        rust.to_string()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_sql_type_to_rust_int() {
        assert_eq!(sql_type_to_rust("INT", false), "i32");
        assert_eq!(sql_type_to_rust("BIGINT", false), "i64");
        assert_eq!(sql_type_to_rust("SMALLINT", false), "i16");
        assert_eq!(sql_type_to_rust("TINYINT", false), "i8");
    }

    #[test]
    fn test_sql_type_to_rust_float() {
        assert_eq!(sql_type_to_rust("FLOAT", false), "f32");
        assert_eq!(sql_type_to_rust("DOUBLE", false), "f64");
        assert_eq!(sql_type_to_rust("DECIMAL(10,2)", false), "f64");
    }

    #[test]
    fn test_sql_type_to_rust_bool() {
        assert_eq!(sql_type_to_rust("BOOLEAN", false), "bool");
        assert_eq!(sql_type_to_rust("TINYINT(1)", false), "i8");
    }

    #[test]
    fn test_sql_type_to_rust_string() {
        assert_eq!(sql_type_to_rust("VARCHAR(255)", false), "String");
        assert_eq!(sql_type_to_rust("TEXT", false), "String");
        assert_eq!(sql_type_to_rust("CHAR(36)", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_binary() {
        assert_eq!(sql_type_to_rust("BLOB", false), "Vec<u8>");
        assert_eq!(sql_type_to_rust("BYTEA", false), "Vec<u8>");
    }

    #[test]
    fn test_sql_type_to_rust_nullable() {
        assert_eq!(sql_type_to_rust("INT", true), "Option<i32>");
        assert_eq!(sql_type_to_rust("VARCHAR(255)", true), "Option<String>");
    }

    #[test]
    fn test_sql_type_to_rust_pg_types() {
        assert_eq!(sql_type_to_rust("int8", false), "i64");
        assert_eq!(sql_type_to_rust("int2", false), "i16");
        assert_eq!(sql_type_to_rust("float8", false), "f64");
        assert_eq!(sql_type_to_rust("float4", false), "f32");
        assert_eq!(sql_type_to_rust("bytea", false), "Vec<u8>");
    }

    #[test]
    fn test_sql_type_to_rust_json_uuid() {
        assert_eq!(sql_type_to_rust("JSON", false), "String");
        assert_eq!(sql_type_to_rust("JSONB", false), "String");
        assert_eq!(sql_type_to_rust("UUID", false), "String");
    }

    #[test]
    fn test_schema_generator_single_table() {
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![
                ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                },
                ColumnSchema {
                    name: "name".to_string(),
                    rust_type: "String".to_string(),
                },
            ],
        }];
        let output = gen.generate(&tables);

        assert!(output.contains("table users {"));
        assert!(output.contains("id: i64,"));
        assert!(output.contains("name: String,"));
        assert!(output.contains("typed_query! {"));
    }

    #[test]
    fn test_schema_generator_multiple_tables() {
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![
            TableSchema {
                name: "users".to_string(),
                columns: vec![ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                }],
            },
            TableSchema {
                name: "orders".to_string(),
                columns: vec![ColumnSchema {
                    name: "order_id".to_string(),
                    rust_type: "i64".to_string(),
                }],
            },
        ];
        let output = gen.generate(&tables);

        assert!(output.contains("table users {"));
        assert!(output.contains("table orders {"));
        // 两个表声明之间应有空行
        let users_end = output.find("}").unwrap();
        let orders_start = output.find("table orders").unwrap();
        let between = &output[users_end..orders_start];
        assert!(between.contains("\n\n"));
    }

    #[test]
    fn test_schema_generator_with_use_statement() {
        let gen = SchemaGenerator::new().emit_use(true);
        let tables = vec![TableSchema {
            name: "t".to_string(),
            columns: vec![],
        }];
        let output = gen.generate(&tables);

        assert!(output.contains("use sz_orm_core::typed_query;"));
    }

    #[test]
    fn test_schema_generator_header() {
        let gen = SchemaGenerator::new();
        let output = gen.generate(&[]);
        assert!(output.contains("Auto-generated"));
        assert!(output.contains("DO NOT EDIT MANUALLY"));
    }

    #[test]
    fn test_schema_generator_custom_header() {
        let gen = SchemaGenerator::new().with_header("// Custom header\n");
        let output = gen.generate(&[]);
        assert!(output.starts_with("// Custom header"));
        assert!(!output.contains("Auto-generated"));
    }

    #[test]
    fn test_schema_generator_empty_tables() {
        let gen = SchemaGenerator::new().emit_use(false);
        let output = gen.generate(&[]);
        // 空表列表也应生成（仅有 header，不应有 typed_query! 块）
        assert!(output.contains("Auto-generated"));
        // 应该没有 typed_query! 块（header 里只是描述性文字，不算块）
        // 通过检查 "typed_query! {" 来判断是否有实际声明
        assert!(!output.contains("typed_query! {"));
    }

    #[test]
    fn test_schema_generator_option_type() {
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![TableSchema {
            name: "products".to_string(),
            columns: vec![ColumnSchema {
                name: "price".to_string(),
                rust_type: "Option<f64>".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        assert!(output.contains("price: Option<f64>,"));
    }

    #[test]
    fn test_schema_generator_compound_type() {
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![TableSchema {
            name: "files".to_string(),
            columns: vec![ColumnSchema {
                name: "content".to_string(),
                rust_type: "Vec<u8>".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        assert!(output.contains("content: Vec<u8>,"));
    }

    #[test]
    fn test_generated_code_is_valid_syntax() {
        // 验证生成的代码包含正确的 typed_query! 调用语法
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![TableSchema {
            name: "typed_validate_test".to_string(),
            columns: vec![
                ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                },
                ColumnSchema {
                    name: "name".to_string(),
                    rust_type: "String".to_string(),
                },
            ],
        }];
        let output = gen.generate(&tables);

        // 验证生成的代码包含 typed_query! 块的完整结构
        assert!(output.contains("typed_query! {"));
        assert!(output.contains("table typed_validate_test {"));
        assert!(output.contains("id: i64,"));
        assert!(output.contains("name: String,"));
        // 块应正确闭合
        let count_open = output.matches("typed_query! {").count();
        let count_close = output.matches("}\n}").count();
        assert_eq!(count_open, 1);
        assert_eq!(count_close, 1);
    }

    // ---- P0 修复：精确匹配测试（杜绝 contains 子串误判） ----

    #[test]
    fn test_sql_type_to_rust_interval_not_int() {
        // 关键修复：INTERVAL 不应被 contains("int") 误判为 i32
        assert_eq!(sql_type_to_rust("INTERVAL", false), "String");
        assert_eq!(sql_type_to_rust("interval", false), "String");
        // PostgreSQL INTERVAL DAY TO SECOND 等变体
        assert_eq!(sql_type_to_rust("INTERVAL DAY TO SECOND", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_mediumint() {
        // MySQL MEDIUMINT 应为 i32
        assert_eq!(sql_type_to_rust("MEDIUMINT", false), "i32");
        assert_eq!(sql_type_to_rust("MEDIUMINT(8)", false), "i32");
    }

    #[test]
    fn test_sql_type_to_rust_integer_alias() {
        // INTEGER 是 INT 的别名
        assert_eq!(sql_type_to_rust("INTEGER", false), "i32");
        assert_eq!(sql_type_to_rust("INTEGER(11)", false), "i32");
    }

    #[test]
    fn test_sql_type_to_rust_serial_types() {
        // PostgreSQL SERIAL/BIGSERIAL/SMALLSERIAL
        assert_eq!(sql_type_to_rust("SERIAL", false), "i32");
        assert_eq!(sql_type_to_rust("BIGSERIAL", false), "i64");
        assert_eq!(sql_type_to_rust("SMALLSERIAL", false), "i16");
    }

    #[test]
    fn test_sql_type_to_rust_unsigned_suffix() {
        // MySQL UNSIGNED 后缀剥离
        assert_eq!(sql_type_to_rust("INT UNSIGNED", false), "i32");
        assert_eq!(sql_type_to_rust("BIGINT UNSIGNED", false), "i64");
        assert_eq!(sql_type_to_rust("TINYINT UNSIGNED", false), "i8");
        assert_eq!(sql_type_to_rust("SMALLINT UNSIGNED", false), "i16");
        assert_eq!(sql_type_to_rust("MEDIUMINT UNSIGNED", false), "i32");
    }

    #[test]
    fn test_sql_type_to_rust_zerofill_suffix() {
        // MySQL ZEROFILL 后缀剥离
        assert_eq!(sql_type_to_rust("INT ZEROFILL", false), "i32");
        assert_eq!(sql_type_to_rust("INT(4) ZEROFILL", false), "i32");
    }

    #[test]
    fn test_sql_type_to_rust_timestamptz() {
        // PostgreSQL TIMESTAMPTZ
        assert_eq!(sql_type_to_rust("TIMESTAMPTZ", false), "String");
        assert_eq!(sql_type_to_rust("timestamptz", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_timetz() {
        // PostgreSQL TIMETZ
        assert_eq!(sql_type_to_rust("TIMETZ", false), "String");
        assert_eq!(sql_type_to_rust("timetz", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_double_precision() {
        // PostgreSQL DOUBLE PRECISION（带空格）
        assert_eq!(sql_type_to_rust("DOUBLE PRECISION", false), "f64");
        assert_eq!(sql_type_to_rust("double precision", false), "f64");
    }

    #[test]
    fn test_sql_type_to_rust_varbinary() {
        // MySQL VARBINARY
        assert_eq!(sql_type_to_rust("VARBINARY(255)", false), "Vec<u8>");
        assert_eq!(sql_type_to_rust("VARBINARY", false), "Vec<u8>");
    }

    #[test]
    fn test_sql_type_to_rust_blob_variants() {
        // MySQL TINYBLOB/MEDIUMBLOB/LONGBLOB
        assert_eq!(sql_type_to_rust("TINYBLOB", false), "Vec<u8>");
        assert_eq!(sql_type_to_rust("MEDIUMBLOB", false), "Vec<u8>");
        assert_eq!(sql_type_to_rust("LONGBLOB", false), "Vec<u8>");
    }

    #[test]
    fn test_sql_type_to_rust_text_variants() {
        // MySQL TINYTEXT/MEDIUMTEXT/LONGTEXT
        assert_eq!(sql_type_to_rust("TINYTEXT", false), "String");
        assert_eq!(sql_type_to_rust("MEDIUMTEXT", false), "String");
        assert_eq!(sql_type_to_rust("LONGTEXT", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_enum_and_set() {
        // MySQL ENUM/SET
        assert_eq!(sql_type_to_rust("ENUM('a','b')", false), "String");
        assert_eq!(sql_type_to_rust("SET('a','b')", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_decimal_with_space() {
        // DECIMAL(10, 2)（参数内含空格）
        assert_eq!(sql_type_to_rust("DECIMAL(10, 2)", false), "f64");
        assert_eq!(sql_type_to_rust("NUMERIC(8, 2)", false), "f64");
    }

    #[test]
    fn test_sql_type_to_rust_unknown_defaults_string() {
        // 未知类型默认为 String
        assert_eq!(sql_type_to_rust("UNKNOWN_TYPE", false), "String");
        assert_eq!(sql_type_to_rust("citext", false), "String");
        assert_eq!(sql_type_to_rust("money", false), "String");
    }

    #[test]
    fn test_sql_type_to_rust_interval_nullable() {
        // INTERVAL 可空 → Option<String>
        assert_eq!(sql_type_to_rust("INTERVAL", true), "Option<String>");
    }

    // ====================================================================
    // #41 修复：Model struct 生成测试
    // ====================================================================

    #[test]
    fn test_to_pascal_case_basic() {
        assert_eq!(to_pascal_case("users"), "Users");
        assert_eq!(to_pascal_case("orders"), "Orders");
    }

    #[test]
    fn test_to_pascal_case_snake_case() {
        assert_eq!(to_pascal_case("order_items"), "OrderItems");
        assert_eq!(to_pascal_case("user_profiles"), "UserProfiles");
    }

    #[test]
    fn test_to_pascal_case_kebab_case() {
        assert_eq!(to_pascal_case("user-profile"), "UserProfile");
        assert_eq!(to_pascal_case("order-item"), "OrderItem");
    }

    #[test]
    fn test_to_pascal_case_with_spaces() {
        assert_eq!(to_pascal_case("user profile"), "UserProfile");
    }

    #[test]
    fn test_to_pascal_case_single_char() {
        assert_eq!(to_pascal_case("a"), "A");
        assert_eq!(to_pascal_case("_a"), "A");
    }

    #[test]
    fn test_to_pascal_case_already_pascal() {
        // 已是 PascalCase 的输入应保持原样（首字母仍大写）
        assert_eq!(to_pascal_case("Users"), "Users");
    }

    #[test]
    fn test_emit_model_structs_generates_struct() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true);
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![
                ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                },
                ColumnSchema {
                    name: "name".to_string(),
                    rust_type: "String".to_string(),
                },
            ],
        }];
        let output = gen.generate(&tables);

        // 应生成 struct Users
        assert!(output.contains("pub struct Users {"));
        assert!(output.contains("pub id: i64,"));
        assert!(output.contains("pub name: String,"));
        // 应生成派生属性
        assert!(output.contains("#[derive("));
        assert!(output.contains("Debug"));
        assert!(output.contains("Clone"));
        // 应生成表名注解
        assert!(output.contains("#[table_name = \"users\"]"));
        // 同时应生成 typed_query! 声明
        assert!(output.contains("typed_query! {"));
        assert!(output.contains("table users {"));
    }

    #[test]
    fn test_emit_model_structs_disabled_by_default() {
        let gen = SchemaGenerator::new().emit_use(false);
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![ColumnSchema {
                name: "id".to_string(),
                rust_type: "i64".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        // 默认不生成 Model struct
        assert!(!output.contains("pub struct Users"));
        // 但应生成 typed_query! 声明
        assert!(output.contains("typed_query! {"));
    }

    #[test]
    fn test_emit_model_structs_multiple_tables() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true);
        let tables = vec![
            TableSchema {
                name: "users".to_string(),
                columns: vec![ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                }],
            },
            TableSchema {
                name: "order_items".to_string(),
                columns: vec![ColumnSchema {
                    name: "item_id".to_string(),
                    rust_type: "i64".to_string(),
                }],
            },
        ];
        let output = gen.generate(&tables);

        // 应生成两个 struct，且 snake_case 表名转换为 PascalCase
        assert!(output.contains("pub struct Users {"));
        assert!(output.contains("pub struct OrderItems {"));
    }

    #[test]
    fn test_emit_model_structs_with_custom_derives() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true)
            .with_model_derives("Debug, Clone");
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![ColumnSchema {
                name: "id".to_string(),
                rust_type: "i64".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        // 应使用自定义派生属性
        assert!(output.contains("#[derive(Debug, Clone)]"));
        // 不应包含默认的 serde 派生
        assert!(!output.contains("serde::Serialize"));
    }

    #[test]
    fn test_emit_model_structs_with_empty_derives() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true)
            .with_model_derives("");
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![ColumnSchema {
                name: "id".to_string(),
                rust_type: "i64".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        // 不应生成 #[derive(...)] 属性
        assert!(!output.contains("#[derive("));
        // 但仍应生成 struct 定义
        assert!(output.contains("pub struct Users {"));
    }

    #[test]
    fn test_emit_model_structs_with_nullable_fields() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true);
        let tables = vec![TableSchema {
            name: "products".to_string(),
            columns: vec![
                ColumnSchema {
                    name: "id".to_string(),
                    rust_type: "i64".to_string(),
                },
                ColumnSchema {
                    name: "price".to_string(),
                    rust_type: "Option<f64>".to_string(),
                },
                ColumnSchema {
                    name: "description".to_string(),
                    rust_type: "Option<String>".to_string(),
                },
            ],
        }];
        let output = gen.generate(&tables);

        assert!(output.contains("pub struct Products {"));
        assert!(output.contains("pub id: i64,"));
        assert!(output.contains("pub price: Option<f64>,"));
        assert!(output.contains("pub description: Option<String>,"));
    }

    #[test]
    fn test_emit_model_structs_with_serde_use() {
        let gen = SchemaGenerator::new()
            .emit_use(true)
            .emit_model_structs(true);
        let tables = vec![TableSchema {
            name: "users".to_string(),
            columns: vec![ColumnSchema {
                name: "id".to_string(),
                rust_type: "i64".to_string(),
            }],
        }];
        let output = gen.generate(&tables);

        // 启用 serde 派生时应生成对应的 use 语句
        assert!(output.contains("use serde::{Serialize, Deserialize};"));
    }

    #[test]
    fn test_emit_model_structs_empty_tables() {
        let gen = SchemaGenerator::new()
            .emit_use(false)
            .emit_model_structs(true);
        let output = gen.generate(&[]);

        // 空表列表不应生成任何 struct
        assert!(!output.contains("pub struct"));
        // 但应有 header
        assert!(output.contains("Auto-generated"));
    }
}