use fallible_iterator::FallibleIterator;

use super::{Error, Parser};
use crate::parser::ast::fmt::ToTokens;
use crate::parser::{
    ast::{Cmd, ParameterInfo, Stmt},
    ParserError,
};

#[test]
fn count_placeholders() {
    let ast = parse_cmd(b"SELECT ? WHERE 1 = ?");
    let mut info = ParameterInfo::default();
    ast.to_tokens(&mut info).unwrap();
    assert_eq!(info.count, 2);
}

#[test]
fn count_numbered_placeholders() {
    let ast = parse_cmd(b"SELECT ?1 WHERE 1 = ?2 AND 0 = ?1");
    let mut info = ParameterInfo::default();
    ast.to_tokens(&mut info).unwrap();
    assert_eq!(info.count, 2);
}

#[test]
fn count_unused_placeholders() {
    let ast = parse_cmd(b"SELECT ?1 WHERE 1 = ?3");
    let mut info = ParameterInfo::default();
    ast.to_tokens(&mut info).unwrap();
    assert_eq!(info.count, 3);
}

#[test]
fn count_named_placeholders() {
    let ast = parse_cmd(b"SELECT :x, :y WHERE 1 = :y");
    let mut info = ParameterInfo::default();
    ast.to_tokens(&mut info).unwrap();
    assert_eq!(info.count, 2);
    assert_eq!(info.names.len(), 2);
    assert!(info.names.contains(":x"));
    assert!(info.names.contains(":y"));
}

#[test]
fn duplicate_column() {
    expect_parser_err_msg(
        b"CREATE TABLE t (x TEXT, x TEXT)",
        "duplicate column name: x",
    );
    expect_parser_err_msg(
        b"CREATE TABLE t (x TEXT, \"x\" TEXT)",
        "duplicate column name: \"x\"",
    );
    expect_parser_err_msg(
        b"CREATE TABLE t (x TEXT, `x` TEXT)",
        "duplicate column name: `x`",
    );
}

#[test]
fn create_table_without_column() {
    expect_parser_err(
        b"CREATE TABLE t ()",
        ParserError::SyntaxError(")".to_owned()),
    );
}

#[test]
fn vtab_args() -> Result<(), Error> {
    let sql = b"CREATE VIRTUAL TABLE mail USING fts3(
  subject VARCHAR(256) NOT NULL,
  body TEXT CHECK(length(body)<10240)
);";
    let r = parse_cmd(sql);
    let Cmd::Stmt(Stmt::CreateVirtualTable(create_virtual_table)) = r else {
        panic!("unexpected AST")
    };
    assert_eq!(create_virtual_table.tbl_name.name, "mail");
    assert_eq!(create_virtual_table.module_name.0, "fts3");
    let args = create_virtual_table.args.as_ref().unwrap();
    assert_eq!(args.len(), 2);
    assert_eq!(args[0], "subject VARCHAR(256) NOT NULL");
    assert_eq!(args[1], "body TEXT CHECK(length(body)<10240)");
    Ok(())
}

#[test]
fn only_semicolons_no_statements() {
    let sqls = ["", ";", ";;;"];
    for sql in &sqls {
        let r = parse(sql.as_bytes());
        assert_eq!(r.unwrap(), None);
    }
}

#[test]
fn extra_semicolons_between_statements() {
    let sqls = [
        "SELECT 1; SELECT 2",
        "SELECT 1; SELECT 2;",
        "; SELECT 1; SELECT 2",
        ";; SELECT 1;; SELECT 2;;",
    ];
    for sql in &sqls {
        let mut parser = Parser::new(sql.as_bytes());
        assert!(matches!(
            parser.next().unwrap(),
            Some(Cmd::Stmt(Stmt::Select { .. }))
        ));
        assert!(matches!(
            parser.next().unwrap(),
            Some(Cmd::Stmt(Stmt::Select { .. }))
        ));
        assert_eq!(parser.next().unwrap(), None);
    }
}

#[test]
fn extra_comments_between_statements() {
    let sqls = [
        "-- abc\nSELECT 1; --def\nSELECT 2 -- ghj",
        "/* abc */ SELECT 1; /* def */ SELECT 2; /* ghj */",
        "/* abc */; SELECT 1 /* def */; SELECT 2 /* ghj */",
        "/* abc */;; SELECT 1;/* def */; SELECT 2; /* ghj */; /* klm */",
    ];
    for sql in &sqls {
        let mut parser = Parser::new(sql.as_bytes());
        assert!(matches!(
            parser.next().unwrap(),
            Some(Cmd::Stmt(Stmt::Select { .. }))
        ));
        assert!(matches!(
            parser.next().unwrap(),
            Some(Cmd::Stmt(Stmt::Select { .. }))
        ));
        assert_eq!(parser.next().unwrap(), None);
    }
}

#[test]
fn insert_mismatch_count() {
    expect_parser_err_msg(b"INSERT INTO t (a, b) VALUES (1)", "1 values for 2 columns");
}

#[test]
fn insert_default_values() {
    expect_parser_err_msg(
        b"INSERT INTO t (a) DEFAULT VALUES",
        "0 values for 1 columns",
    );
}

#[test]
fn create_view_mismatch_count() {
    expect_parser_err_msg(
        b"CREATE VIEW v (c1, c2) AS SELECT 1",
        "expected 2 columns for v but got 1",
    );
}

#[test]
fn create_view_duplicate_column_name() {
    expect_parser_err_msg(
        b"CREATE VIEW v (c1, c1) AS SELECT 1, 2",
        "duplicate column name: c1",
    );
}

#[test]
fn create_table_without_rowid_missing_pk() {
    expect_parser_err_msg(
        b"CREATE TABLE t (c1) WITHOUT ROWID",
        "PRIMARY KEY missing on table t",
    );
}

#[test]
fn create_temporary_table_with_qualified_name() {
    expect_parser_err_msg(
        b"CREATE TEMPORARY TABLE mem.x AS SELECT 1",
        "temporary table name must be unqualified",
    );
    parse_cmd(b"CREATE TEMPORARY TABLE temp.x AS SELECT 1");
}

#[test]
fn create_table_with_only_generated_column() {
    expect_parser_err_msg(
        b"CREATE TABLE test(data AS (1))",
        "must have at least one non-generated column",
    );
}

#[test]
fn create_strict_table_missing_datatype() {
    expect_parser_err_msg(b"CREATE TABLE t (c1) STRICT", "missing datatype for t.c1");
}

#[test]
fn create_strict_table_unknown_datatype() {
    expect_parser_err_msg(
        b"CREATE TABLE t (c1 BOOL) STRICT",
        "unknown datatype for t.c1: \"BOOL\"",
    );
}

#[test]
fn foreign_key_on_column() {
    expect_parser_err_msg(
        b"CREATE TABLE t(a REFERENCES o(a,b))",
        "foreign key on a should reference only one column of table o",
    );
}

#[test]
fn create_strict_table_generated_column() {
    parse_cmd(
        b"CREATE TABLE IF NOT EXISTS transactions (
      debit REAL,
      credit REAL,
      amount REAL GENERATED ALWAYS AS (ifnull(credit, 0.0) -ifnull(debit, 0.0))
  ) STRICT;",
    );
}

#[test]
fn selects_compound_mismatch_columns_count() {
    expect_parser_err_msg(
        b"SELECT 1 UNION SELECT 1, 2",
        "SELECTs to the left and right of UNION do not have the same number of result columns",
    );
}

#[test]
fn delete_order_by_without_limit() {
    expect_parser_err_msg(
        b"DELETE FROM t ORDER BY x",
        "ORDER BY without LIMIT on DELETE",
    );
}

#[test]
fn update_order_by_without_limit() {
    expect_parser_err_msg(
        b"UPDATE t SET x = 1 ORDER BY x",
        "ORDER BY without LIMIT on UPDATE",
    );
}

#[test]
fn values_mismatch_columns_count() {
    expect_parser_err_msg(
        b"INSERT INTO t VALUES (1), (1,2)",
        "all VALUES must have the same number of terms",
    );
}

#[test]
fn column_specified_more_than_once() {
    expect_parser_err_msg(
        b"INSERT INTO t (n, n, m) VALUES (1, 0, 2)",
        "column \"n\" specified more than once",
    )
}

#[test]
fn alter_add_column_primary_key() {
    expect_parser_err_msg(
        b"ALTER TABLE t ADD COLUMN c PRIMARY KEY",
        "Cannot add a PRIMARY KEY column",
    );
}

#[test]
fn alter_add_column_unique() {
    expect_parser_err_msg(
        b"ALTER TABLE t ADD COLUMN c UNIQUE",
        "Cannot add a UNIQUE column",
    );
}

#[test]
fn alter_rename_same() {
    expect_parser_err_msg(
        b"ALTER TABLE t RENAME TO t",
        "there is already another table or index with this name: t",
    );
}

#[test]
fn natural_join_on() {
    expect_parser_err_msg(
        b"SELECT x FROM t NATURAL JOIN t USING (x)",
        "a NATURAL join may not have an ON or USING clause",
    );
    expect_parser_err_msg(
        b"SELECT x FROM t NATURAL JOIN t ON t.x = t.x",
        "a NATURAL join may not have an ON or USING clause",
    );
}

#[test]
fn missing_join_clause() {
    expect_parser_err_msg(
        b"SELECT a FROM tt ON b",
        "a JOIN clause is required before ON",
    );
}

#[test]
fn cast_without_typename() {
    parse_cmd(b"SELECT CAST(a AS ) FROM t");
}

#[test]
fn unknown_table_option() {
    expect_parser_err_msg(b"CREATE TABLE t(x)o", "unknown table option: o");
    expect_parser_err_msg(b"CREATE TABLE t(x) WITHOUT o", "unknown table option: o");
}

#[test]
fn qualified_table_name_within_triggers() {
    expect_parser_err_msg(
        b"CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
            DELETE FROM main.t2;
          END;",
        "qualified table names are not allowed on INSERT, UPDATE, and DELETE statements \
          within triggers",
    );
}

#[test]
fn select_from_error_stops_at_first_error() {
    let mut parser = Parser::new(b"SELECT FROM foo;");

    // First next() call should return the first syntax error
    let err = parser.next().unwrap_err();
    assert!(matches!(err, Error::ParserError(_, _, _)));

    // Second next() call should return Ok(None) since parsing should have stopped
    assert_eq!(parser.next().unwrap(), None);

    // Third next() call should also return Ok(None)
    assert_eq!(parser.next().unwrap(), None);
}

#[test]
fn indexed_by_clause_within_triggers() {
    expect_parser_err_msg(
        b"CREATE TRIGGER main.t16err5 AFTER INSERT ON tA BEGIN
            UPDATE t16 INDEXED BY t16a SET rowid=rowid+1 WHERE a=1;
          END;",
        "the INDEXED BY clause is not allowed on UPDATE or DELETE statements \
           within triggers",
    );
    expect_parser_err_msg(
        b"CREATE TRIGGER main.t16err6 AFTER INSERT ON tA BEGIN
            DELETE FROM t16 NOT INDEXED WHERE a=123;
          END;",
        "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements \
         within triggers",
    );
}

fn expect_parser_err_msg(input: &[u8], error_msg: &str) {
    expect_parser_err(input, ParserError::Custom(error_msg.to_owned()))
}
fn expect_parser_err(input: &[u8], err: ParserError) {
    let r = parse(input);
    if let Error::ParserError(e, _, _) = r.unwrap_err() {
        assert_eq!(e, err);
    } else {
        panic!("unexpected error type")
    };
}
fn parse_cmd(input: &[u8]) -> Cmd {
    parse(input).unwrap().unwrap()
}
fn parse(input: &[u8]) -> Result<Option<Cmd>, Error> {
    let mut parser = Parser::new(input);
    parser.next()
}