vibesql-cli 0.1.3

//! TypeScript code generation from database schema
//!
//! This module generates TypeScript type definitions from VibeSQL database schemas,
//! enabling type-safe database interactions in TypeScript projects.

use std::fs;
use std::path::Path;

use anyhow::Result;
use vibesql_catalog::TableSchema;
use vibesql_parser::Parser;
use vibesql_storage::Database;
use vibesql_types::DataType;

/// Configuration for TypeScript code generation
#[derive(Debug, Clone)]
pub struct CodegenConfig {
    /// Output file path (stored for informational purposes)
    #[allow(dead_code)]
    pub output: String,
    /// Whether to generate table metadata objects
    pub include_metadata: bool,
    /// Whether to use camelCase for property names
    pub camel_case: bool,
}

impl Default for CodegenConfig {
    fn default() -> Self {
        CodegenConfig { output: "types.ts".to_string(), include_metadata: true, camel_case: false }
    }
}

/// Generate TypeScript types from a database
pub fn generate_from_database(db: &Database, config: &CodegenConfig) -> Result<String> {
    let tables = db.list_tables();
    let mut schemas: Vec<&TableSchema> = Vec::new();

    for table_name in &tables {
        if let Some(table) = db.get_table(table_name) {
            schemas.push(&table.schema);
        }
    }

    generate_typescript(&schemas, config)
}

/// Generate TypeScript types from a SQL schema file
pub fn generate_from_schema_file(path: &str, config: &CodegenConfig) -> Result<String> {
    let sql = fs::read_to_string(path)?;
    generate_from_sql(&sql, config)
}

/// Generate TypeScript types from SQL DDL statements
pub fn generate_from_sql(sql: &str, config: &CodegenConfig) -> Result<String> {
    let mut db = Database::new();

    // Pre-process SQL to strip comments before splitting
    let sql = strip_sql_comments(sql);

    // Split and execute each statement
    for stmt_sql in split_statements(&sql) {
        let trimmed = stmt_sql.trim();
        if trimmed.is_empty() {
            continue;
        }

        // Only process CREATE TABLE statements
        if trimmed.to_uppercase().starts_with("CREATE TABLE") {
            match Parser::parse_sql(trimmed) {
                Ok(vibesql_ast::Statement::CreateTable(create_stmt)) => {
                    if let Err(e) =
                        vibesql_executor::CreateTableExecutor::execute(&create_stmt, &mut db)
                    {
                        eprintln!("Warning: Failed to execute CREATE TABLE: {}", e);
                    }
                }
                Ok(_) => {
                    // Not a CREATE TABLE, skip
                }
                Err(e) => {
                    eprintln!("Warning: Failed to parse statement: {}", e);
                }
            }
        }
    }

    generate_from_database(&db, config)
}

/// Strip SQL comments from a string
///
/// Handles:
/// - Single-line comments starting with --
/// - Multi-line comments /* ... */
fn strip_sql_comments(sql: &str) -> String {
    let mut result = String::with_capacity(sql.len());
    let mut chars = sql.chars().peekable();
    let mut in_string = false;
    let mut string_char = '"';

    while let Some(ch) = chars.next() {
        // Track if we're inside a string literal
        if (ch == '\'' || ch == '"') && !in_string {
            in_string = true;
            string_char = ch;
            result.push(ch);
            continue;
        }

        if in_string {
            result.push(ch);
            if ch == string_char {
                in_string = false;
            }
            continue;
        }

        // Handle single-line comments (--)
        if ch == '-' && chars.peek() == Some(&'-') {
            chars.next(); // consume second -
                          // Skip until end of line
            for c in chars.by_ref() {
                if c == '\n' {
                    result.push('\n'); // Preserve line breaks
                    break;
                }
            }
            continue;
        }

        // Handle multi-line comments (/* ... */)
        if ch == '/' && chars.peek() == Some(&'*') {
            chars.next(); // consume *
                          // Skip until */
            while let Some(c) = chars.next() {
                if c == '*' && chars.peek() == Some(&'/') {
                    chars.next(); // consume /
                    break;
                }
            }
            continue;
        }

        result.push(ch);
    }

    result
}

/// Split SQL into individual statements
fn split_statements(sql: &str) -> Vec<&str> {
    sql.split(';').filter(|s| !s.trim().is_empty()).collect()
}

/// Generate TypeScript code from table schemas
fn generate_typescript(schemas: &[&TableSchema], config: &CodegenConfig) -> Result<String> {
    let mut output = String::new();

    // Header
    output.push_str("// Auto-generated by vibesql codegen - DO NOT EDIT\n");
    output.push_str("// Generated from VibeSQL database schema\n\n");

    // Sort tables alphabetically for consistent output
    let mut sorted_schemas: Vec<&&TableSchema> = schemas.iter().collect();
    sorted_schemas.sort_by(|a, b| a.name.cmp(&b.name));

    // Generate interfaces for each table
    for schema in &sorted_schemas {
        output.push_str(&generate_interface(schema, config));
        output.push('\n');
    }

    // Generate table metadata if requested
    if config.include_metadata {
        output.push_str(&generate_metadata(&sorted_schemas, config));
    }

    Ok(output)
}

/// Generate a TypeScript interface for a table
fn generate_interface(schema: &TableSchema, config: &CodegenConfig) -> String {
    let mut output = String::new();

    // Interface name is PascalCase version of table name
    let interface_name = to_pascal_case(&schema.name);

    output.push_str(&format!("export interface {} {{\n", interface_name));

    for column in &schema.columns {
        let prop_name = if config.camel_case {
            to_camel_case(&column.name)
        } else {
            column.name.to_lowercase()
        };

        let ts_type = sql_type_to_typescript(&column.data_type);
        let nullable_suffix = if column.nullable { " | null" } else { "" };

        output.push_str(&format!("  {}: {}{};\n", prop_name, ts_type, nullable_suffix));
    }

    output.push_str("}\n");
    output
}

/// Generate table metadata object
fn generate_metadata(schemas: &[&&TableSchema], config: &CodegenConfig) -> String {
    let mut output = String::new();

    output.push_str("// Table metadata for runtime use\n");
    output.push_str("export const tables = {\n");

    for schema in schemas.iter() {
        let table_key = if config.camel_case {
            to_camel_case(&schema.name)
        } else {
            schema.name.to_lowercase()
        };

        output.push_str(&format!("  {}: {{\n", table_key));
        output.push_str(&format!("    name: '{}',\n", schema.name));

        // Columns array
        let columns: Vec<String> = schema
            .columns
            .iter()
            .map(|c| {
                if config.camel_case {
                    format!("'{}'", to_camel_case(&c.name))
                } else {
                    format!("'{}'", c.name.to_lowercase())
                }
            })
            .collect();
        output.push_str(&format!("    columns: [{}],\n", columns.join(", ")));

        // Primary key
        if let Some(pk) = &schema.primary_key {
            if pk.len() == 1 {
                let pk_name =
                    if config.camel_case { to_camel_case(&pk[0]) } else { pk[0].to_lowercase() };
                output.push_str(&format!("    primaryKey: '{}',\n", pk_name));
            } else {
                let pk_names: Vec<String> = pk
                    .iter()
                    .map(|p| {
                        if config.camel_case {
                            format!("'{}'", to_camel_case(p))
                        } else {
                            format!("'{}'", p.to_lowercase())
                        }
                    })
                    .collect();
                output.push_str(&format!("    primaryKey: [{}],\n", pk_names.join(", ")));
            }
        }

        // Column types mapping
        output.push_str("    columnTypes: {\n");
        for column in &schema.columns {
            let col_name = if config.camel_case {
                to_camel_case(&column.name)
            } else {
                column.name.to_lowercase()
            };
            let sql_type = format_sql_type(&column.data_type);
            output.push_str(&format!("      {}: '{}',\n", col_name, sql_type));
        }
        output.push_str("    },\n");

        // Nullable columns
        let nullable_cols: Vec<String> = schema
            .columns
            .iter()
            .filter(|c| c.nullable)
            .map(|c| {
                if config.camel_case {
                    format!("'{}'", to_camel_case(&c.name))
                } else {
                    format!("'{}'", c.name.to_lowercase())
                }
            })
            .collect();
        output.push_str(&format!("    nullable: [{}],\n", nullable_cols.join(", ")));

        output.push_str("  },\n");
    }

    output.push_str("} as const;\n\n");

    // Generate type helpers
    output.push_str("// Type helper for table names\n");
    output.push_str("export type TableName = keyof typeof tables;\n\n");

    // Generate row types
    output.push_str("// Row type mapping\n");
    output.push_str("export type TableRow<T extends TableName> = \n");
    for (i, schema) in schemas.iter().enumerate() {
        let table_key = if config.camel_case {
            to_camel_case(&schema.name)
        } else {
            schema.name.to_lowercase()
        };
        let interface_name = to_pascal_case(&schema.name);
        if i == 0 {
            output.push_str(&format!("  T extends '{}' ? {} :\n", table_key, interface_name));
        } else if i == schemas.len() - 1 {
            output.push_str(&format!("  T extends '{}' ? {} :\n", table_key, interface_name));
            output.push_str("  never;\n");
        } else {
            output.push_str(&format!("  T extends '{}' ? {} :\n", table_key, interface_name));
        }
    }

    output
}

/// Convert SQL data type to TypeScript type
fn sql_type_to_typescript(data_type: &DataType) -> &'static str {
    match data_type {
        // Numeric types -> number
        DataType::Integer
        | DataType::Smallint
        | DataType::Bigint
        | DataType::Unsigned
        | DataType::Real
        | DataType::Float { .. }
        | DataType::DoublePrecision => "number",

        // Decimal/Numeric -> string (for precision)
        DataType::Decimal { .. } | DataType::Numeric { .. } => "string",

        // String types -> string
        DataType::Character { .. }
        | DataType::Varchar { .. }
        | DataType::CharacterLargeObject
        | DataType::Name => "string",

        // Boolean -> boolean
        DataType::Boolean => "boolean",

        // Date/time types -> Date
        DataType::Date | DataType::Time { .. } | DataType::Timestamp { .. } => "Date",

        // Interval -> string representation
        DataType::Interval { .. } => "string",

        // Binary types -> Uint8Array
        DataType::BinaryLargeObject | DataType::Bit { .. } => "Uint8Array",

        // Vector -> number[]
        DataType::Vector { .. } => "number[]",

        // User-defined types -> unknown
        DataType::UserDefined { .. } => "unknown",

        // NULL type -> null
        DataType::Null => "null",
    }
}

/// Format SQL type as string for metadata
fn format_sql_type(data_type: &DataType) -> String {
    match data_type {
        DataType::Integer => "INTEGER".to_string(),
        DataType::Smallint => "SMALLINT".to_string(),
        DataType::Bigint => "BIGINT".to_string(),
        DataType::Unsigned => "UNSIGNED BIGINT".to_string(),
        DataType::Real => "REAL".to_string(),
        DataType::Float { precision } => format!("FLOAT({})", precision),
        DataType::DoublePrecision => "DOUBLE PRECISION".to_string(),
        DataType::Decimal { precision, scale } => format!("DECIMAL({}, {})", precision, scale),
        DataType::Numeric { precision, scale } => format!("NUMERIC({}, {})", precision, scale),
        DataType::Character { length } => format!("CHAR({})", length),
        DataType::Varchar { max_length } => {
            if let Some(len) = max_length {
                format!("VARCHAR({})", len)
            } else {
                "VARCHAR".to_string()
            }
        }
        DataType::CharacterLargeObject => "CLOB".to_string(),
        DataType::Name => "NAME".to_string(),
        DataType::Boolean => "BOOLEAN".to_string(),
        DataType::Date => "DATE".to_string(),
        DataType::Time { with_timezone } => {
            if *with_timezone {
                "TIME WITH TIME ZONE".to_string()
            } else {
                "TIME".to_string()
            }
        }
        DataType::Timestamp { with_timezone } => {
            if *with_timezone {
                "TIMESTAMP WITH TIME ZONE".to_string()
            } else {
                "TIMESTAMP".to_string()
            }
        }
        DataType::Interval { start_field, end_field } => {
            if let Some(end) = end_field {
                format!("INTERVAL {:?} TO {:?}", start_field, end)
            } else {
                format!("INTERVAL {:?}", start_field)
            }
        }
        DataType::BinaryLargeObject => "BLOB".to_string(),
        DataType::Bit { length } => {
            if let Some(len) = length {
                format!("BIT({})", len)
            } else {
                "BIT".to_string()
            }
        }
        DataType::Vector { dimensions } => format!("VECTOR({})", dimensions),
        DataType::UserDefined { type_name } => type_name.clone(),
        DataType::Null => "NULL".to_string(),
    }
}

/// Convert snake_case or UPPER_CASE to PascalCase
fn to_pascal_case(s: &str) -> String {
    s.split('_')
        .map(|word| {
            let mut chars = word.chars();
            match chars.next() {
                Some(first) => {
                    first.to_uppercase().chain(chars.flat_map(|c| c.to_lowercase())).collect()
                }
                None => String::new(),
            }
        })
        .collect()
}

/// Convert snake_case or UPPER_CASE to camelCase
fn to_camel_case(s: &str) -> String {
    let pascal = to_pascal_case(s);
    let mut chars = pascal.chars();
    match chars.next() {
        Some(first) => first.to_lowercase().chain(chars).collect(),
        None => String::new(),
    }
}

/// Write generated TypeScript to a file
pub fn write_to_file(typescript: &str, path: &str) -> Result<()> {
    let path = Path::new(path);

    // Create parent directories if needed
    if let Some(parent) = path.parent() {
        if !parent.exists() {
            fs::create_dir_all(parent)?;
        }
    }

    fs::write(path, typescript)?;
    Ok(())
}

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

    fn create_test_schema() -> TableSchema {
        let columns = vec![
            ColumnSchema::new("id".to_string(), DataType::Integer, false),
            ColumnSchema::new(
                "email".to_string(),
                DataType::Varchar { max_length: Some(255) },
                false,
            ),
            ColumnSchema::new(
                "name".to_string(),
                DataType::Varchar { max_length: Some(100) },
                true,
            ),
            ColumnSchema::new(
                "created_at".to_string(),
                DataType::Timestamp { with_timezone: false },
                false,
            ),
            ColumnSchema::new(
                "balance".to_string(),
                DataType::Decimal { precision: 10, scale: 2 },
                true,
            ),
            ColumnSchema::new("is_active".to_string(), DataType::Boolean, false),
        ];
        TableSchema::with_primary_key("users".to_string(), columns, vec!["id".to_string()])
    }

    #[test]
    fn test_to_pascal_case() {
        assert_eq!(to_pascal_case("users"), "Users");
        assert_eq!(to_pascal_case("user_posts"), "UserPosts");
        assert_eq!(to_pascal_case("USER_POSTS"), "UserPosts");
        assert_eq!(to_pascal_case("USERS"), "Users");
    }

    #[test]
    fn test_to_camel_case() {
        assert_eq!(to_camel_case("users"), "users");
        assert_eq!(to_camel_case("user_posts"), "userPosts");
        assert_eq!(to_camel_case("USER_POSTS"), "userPosts");
        assert_eq!(to_camel_case("USERS"), "users");
    }

    #[test]
    fn test_sql_type_to_typescript() {
        assert_eq!(sql_type_to_typescript(&DataType::Integer), "number");
        assert_eq!(sql_type_to_typescript(&DataType::Bigint), "number");
        assert_eq!(sql_type_to_typescript(&DataType::Varchar { max_length: Some(255) }), "string");
        assert_eq!(sql_type_to_typescript(&DataType::Boolean), "boolean");
        assert_eq!(sql_type_to_typescript(&DataType::Timestamp { with_timezone: false }), "Date");
        assert_eq!(
            sql_type_to_typescript(&DataType::Decimal { precision: 10, scale: 2 }),
            "string"
        );
        assert_eq!(sql_type_to_typescript(&DataType::Vector { dimensions: 128 }), "number[]");
    }

    #[test]
    fn test_generate_interface() {
        let schema = create_test_schema();
        let config = CodegenConfig::default();
        let result = generate_interface(&schema, &config);

        assert!(result.contains("export interface Users {"));
        assert!(result.contains("id: number;"));
        assert!(result.contains("email: string;"));
        assert!(result.contains("name: string | null;"));
        assert!(result.contains("created_at: Date;"));
        assert!(result.contains("balance: string | null;")); // Decimal -> string
        assert!(result.contains("is_active: boolean;"));
    }

    #[test]
    fn test_generate_interface_camel_case() {
        let schema = create_test_schema();
        let config = CodegenConfig { camel_case: true, ..Default::default() };
        let result = generate_interface(&schema, &config);

        assert!(result.contains("createdAt: Date;"));
        assert!(result.contains("isActive: boolean;"));
    }

    #[test]
    fn test_generate_from_sql() {
        let sql = r#"
            CREATE TABLE users (
                id INTEGER PRIMARY KEY,
                email VARCHAR(255) NOT NULL,
                name VARCHAR(100)
            );

            CREATE TABLE posts (
                id INTEGER PRIMARY KEY,
                user_id INTEGER NOT NULL,
                title VARCHAR(255) NOT NULL,
                content TEXT,
                published BOOLEAN DEFAULT FALSE
            );
        "#;

        let config = CodegenConfig::default();
        let result = generate_from_sql(sql, &config).unwrap();

        assert!(result.contains("export interface Users {"));
        assert!(result.contains("export interface Posts {"));
        assert!(result.contains("export const tables = {"));
    }

    #[test]
    fn test_generate_metadata() {
        let schema = create_test_schema();
        let schemas: Vec<&TableSchema> = vec![&schema];
        let schema_refs: Vec<&&TableSchema> = schemas.iter().collect();
        let config = CodegenConfig::default();
        let result = generate_metadata(&schema_refs, &config);

        assert!(result.contains("export const tables = {"));
        assert!(result.contains("users: {"));
        assert!(result.contains("name: 'users'"));
        assert!(result.contains("primaryKey: 'id'"));
        assert!(result.contains("columns: ["));
        assert!(result.contains("columnTypes: {"));
        assert!(result.contains("nullable: ["));
        assert!(result.contains("export type TableName = keyof typeof tables;"));
        assert!(result.contains("export type TableRow<T extends TableName>"));
    }

    #[test]
    fn test_strip_sql_comments_single_line() {
        let sql = "-- This is a comment\nCREATE TABLE users (id INT);";
        let result = strip_sql_comments(sql);
        assert!(!result.contains("This is a comment"));
        assert!(result.contains("CREATE TABLE users"));
    }

    #[test]
    fn test_strip_sql_comments_multi_line() {
        let sql = "/* Multi\nline\ncomment */\nCREATE TABLE users (id INT);";
        let result = strip_sql_comments(sql);
        assert!(!result.contains("Multi"));
        assert!(!result.contains("line"));
        assert!(!result.contains("comment"));
        assert!(result.contains("CREATE TABLE users"));
    }

    #[test]
    fn test_strip_sql_comments_inline() {
        let sql = "CREATE TABLE users (id INT); -- inline comment\nCREATE TABLE posts (id INT);";
        let result = strip_sql_comments(sql);
        assert!(!result.contains("inline comment"));
        assert!(result.contains("CREATE TABLE users"));
        assert!(result.contains("CREATE TABLE posts"));
    }

    #[test]
    fn test_strip_sql_comments_preserves_strings() {
        let sql = "CREATE TABLE users (name VARCHAR(100) DEFAULT '--not a comment');";
        let result = strip_sql_comments(sql);
        assert!(result.contains("'--not a comment'"));
    }

    #[test]
    fn test_generate_from_sql_with_comments() {
        let sql = r#"
            -- Database schema for application
            /*
             * User management tables
             */
            CREATE TABLE users (
                id INTEGER PRIMARY KEY,
                email VARCHAR(255) NOT NULL -- User's email
            );

            -- Posts table
            CREATE TABLE posts (
                id INTEGER PRIMARY KEY,
                user_id INTEGER NOT NULL
            );
        "#;

        let config = CodegenConfig::default();
        let result = generate_from_sql(sql, &config).unwrap();

        assert!(result.contains("export interface Users {"));
        assert!(result.contains("export interface Posts {"));
        assert!(!result.contains("Database schema for application"));
        assert!(!result.contains("User management tables"));
    }
}