use std::rc::Rc;
use crate::{ColumnDef, backend::TableBuilder, foreign_key::*, types::*, prepare::*};

/// Create a table
/// 
/// # Examples
/// 
/// ```
/// use sea_query::{*, tests_cfg::*};
/// 
/// let table = Table::create()
///     .table(Char::Table)
///     .create_if_not_exists()
///     .col(ColumnDef::new(Char::Id).integer().not_null().auto_increment().primary_key())
///     .col(ColumnDef::new(Char::FontSize).integer().not_null())
///     .col(ColumnDef::new(Char::Character).string().not_null())
///     .col(ColumnDef::new(Char::SizeW).integer().not_null())
///     .col(ColumnDef::new(Char::SizeH).integer().not_null())
///     .col(ColumnDef::new(Char::FontId).integer().default(Value::Null))
///     .foreign_key(
///         ForeignKey::create()
///             .name("FK_2e303c3a712662f1fc2a4d0aad6")
///             .table(Char::Table, Font::Table)
///             .col(Char::FontId, Font::Id)
///             .on_delete(ForeignKeyAction::Cascade)
///             .on_update(ForeignKeyAction::Cascade)
///     )
///     .to_owned();
/// 
/// assert_eq!(
///     table.to_string(MysqlQueryBuilder),
///     vec![
///         r#"CREATE TABLE IF NOT EXISTS `character` ("#,
///             r#"`id` int NOT NULL AUTO_INCREMENT PRIMARY KEY,"#,
///             r#"`font_size` int NOT NULL,"#,
///             r#"`character` varchar(255) NOT NULL,"#,
///             r#"`size_w` int NOT NULL,"#,
///             r#"`size_h` int NOT NULL,"#,
///             r#"`font_id` int DEFAULT NULL,"#,
///             r#"CONSTRAINT `FK_2e303c3a712662f1fc2a4d0aad6`"#,
///                 r#"FOREIGN KEY `FK_2e303c3a712662f1fc2a4d0aad6` (`font_id`) REFERENCES `font` (`id`)"#,
///                 r#"ON DELETE CASCADE ON UPDATE CASCADE"#,
///         r#")"#,
///     ].join(" ")
/// );
/// assert_eq!(
///     table.to_string(PostgresQueryBuilder),
///     vec![
///         r#"CREATE TABLE IF NOT EXISTS "character" ("#,
///             r#""id" serial NOT NULL PRIMARY KEY,"#,
///             r#""font_size" integer NOT NULL,"#,
///             r#""character" varchar NOT NULL,"#,
///             r#""size_w" integer NOT NULL,"#,
///             r#""size_h" integer NOT NULL,"#,
///             r#""font_id" integer DEFAULT NULL,"#,
///             r#"CONSTRAINT "FK_2e303c3a712662f1fc2a4d0aad6""#,
///                 r#"FOREIGN KEY ("font_id") REFERENCES "font" ("id")"#,
///                 r#"ON DELETE CASCADE ON UPDATE CASCADE"#,
///         r#")"#,
///     ].join(" ")
/// );
/// assert_eq!(
///     table.to_string(SqliteQueryBuilder),
///     vec![
///        r#"CREATE TABLE IF NOT EXISTS `character` ("#,
///            r#"`id` integer NOT NULL PRIMARY KEY AUTOINCREMENT,"#,
///            r#"`font_size` integer NOT NULL,"#,
///            r#"`character` text NOT NULL,"#,
///            r#"`size_w` integer NOT NULL,"#,
///            r#"`size_h` integer NOT NULL,"#,
///            r#"`font_id` integer DEFAULT NULL,"#,
///            r#"FOREIGN KEY (`font_id`) REFERENCES `font` (`id`) ON DELETE CASCADE ON UPDATE CASCADE"#,
///        r#")"#,
///     ].join(" ")
/// );
/// ```
#[derive(Debug, Clone)]
pub struct TableCreateStatement {
    pub(crate) table: Option<Rc<dyn Iden>>,
    pub(crate) columns: Vec<ColumnDef>,
    pub(crate) options: Vec<TableOpt>,
    pub(crate) partitions: Vec<TablePartition>,
    pub(crate) foreign_keys: Vec<ForeignKeyCreateStatement>,
    pub(crate) create_if_not_exists: bool,
}

/// All available table options
#[derive(Debug, Clone)]
pub enum TableOpt {
    Engine(String),
    Collate(String),
    CharacterSet(String),
}

/// All available table partition options
#[derive(Debug, Clone)]
pub enum TablePartition {

}

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

impl TableCreateStatement {
    /// Construct create table statement
    pub fn new() -> Self {
        Self {
            table: None,
            columns: Vec::new(),
            options: Vec::new(),
            partitions: Vec::new(),
            foreign_keys: Vec::new(),
            create_if_not_exists: false,
        }
    }

    /// Create table if table not exists
    pub fn create_if_not_exists(&mut self) -> &mut Self {
        self.create_if_not_exists = true;
        self
    }

    /// Set table name
    pub fn table<T: 'static>(&mut self, table: T) -> &mut Self
        where T: Iden {
        self.table = Some(Rc::new(table));
        self
    }

    /// Add a new table column
    pub fn col(&mut self, column: ColumnDef) -> &mut Self {
        let mut column = column;
        column.table = self.table.clone();
        self.columns.push(column);
        self
    }

    /// Add a foreign key
    pub fn foreign_key(&mut self, foreign_key: ForeignKeyCreateStatement) -> &mut Self {
        let mut foreign_key = foreign_key;
        foreign_key.inside_table_creation = true;
        self.foreign_keys.push(foreign_key);
        self
    }

    /// Set database engine (for MySQL only)
    pub fn engine(&mut self, string: &str) -> &mut Self {
        self.opt(TableOpt::Engine(string.into()));
        self
    }

    /// Set database collate (for MySQL only)
    pub fn collate(&mut self, string: &str) -> &mut Self {
        self.opt(TableOpt::Collate(string.into()));
        self
    }

    /// Set database character set (for MySQL only)
    pub fn character_set(&mut self, string: &str) -> &mut Self {
        self.opt(TableOpt::CharacterSet(string.into()));
        self
    }

    fn opt(&mut self, option: TableOpt) -> &mut Self {
        self.options.push(option);
        self
    }

    #[allow(dead_code)]
    fn partition(&mut self, partition: TablePartition) -> &mut Self {
        self.partitions.push(partition);
        self
    }

    /// Build corresponding SQL statement for certain database backend and return SQL string
    pub fn build<T: TableBuilder>(&self, table_builder: T) -> String {
        let mut sql = SqlWriter::new();
        table_builder.prepare_table_create_statement(self, &mut sql);
        sql.result()
    }

    /// Build corresponding SQL statement for certain database backend and return SQL string
    pub fn build_any(&self, table_builder: &dyn TableBuilder) -> String {
        let mut sql = SqlWriter::new();
        table_builder.prepare_table_create_statement(self, &mut sql);
        sql.result()
    }

    /// Build corresponding SQL statement for certain database backend and return SQL string
    pub fn to_string<T: TableBuilder>(&self, table_builder: T) -> String {
        self.build(table_builder)
    }
}