package dao

import "testing"

func TestEzSort(t *testing.T) {
	tests := []struct {
		name string
		in   string
		want string
	}{
		{name: "empty", in: "", want: ""},
		{name: "spaces", in: "   ", want: ""},
		{name: "tabs", in: "\t\t", want: ""},
		{name: "comma only", in: ",", want: ""},
		{name: "direction only", in: "desc", want: ""},
		{name: "column only", in: "pinned", want: ""},

		{name: "one column desc", in: "pinned desc", want: "`pinned` DESC"},
		{name: "one column asc", in: "weight asc", want: "`weight` ASC"},
		{name: "direction uppercase", in: "pinned DESC", want: "`pinned` DESC"},
		{name: "direction mixed case", in: "pinned DeSc", want: "`pinned` DESC"},
		{name: "column case kept", in: "Pinned desc", want: "`Pinned` DESC"},
		{name: "underscore column", in: "_pinned desc", want: "`_pinned` DESC"},
		{name: "digit in column", in: "weight2 desc", want: "`weight2` DESC"},
		{name: "extra inner spaces", in: "pinned    desc", want: "`pinned` DESC"},
		{name: "leading and trailing spaces", in: "  pinned desc  ", want: "`pinned` DESC"},
		{name: "tab between column and direction", in: "pinned\tdesc", want: "`pinned` DESC"},

		{name: "two columns", in: "pinned desc, weight desc", want: "`pinned` DESC,`weight` DESC"},
		{name: "mixed directions", in: "pinned asc, weight desc", want: "`pinned` ASC,`weight` DESC"},
		{name: "no space after comma", in: "pinned desc,weight desc", want: "`pinned` DESC,`weight` DESC"},
		{name: "spaces around comma", in: "  pinned   desc  ,   weight    ASC  ", want: "`pinned` DESC,`weight` ASC"},
		{name: "three columns", in: "a desc, b asc, c_2 DESC", want: "`a` DESC,`b` ASC,`c_2` DESC"},

		{name: "trailing comma", in: "pinned desc,", want: ""},
		{name: "leading comma", in: ",pinned desc", want: ""},
		{name: "double comma", in: "pinned desc,,weight desc", want: ""},
		{name: "second missing direction", in: "pinned desc, weight", want: ""},
		{name: "first missing direction", in: "pinned, weight desc", want: ""},
		{name: "extra token", in: "pinned desc extra", want: ""},
		{name: "extra token on second", in: "pinned desc, weight desc extra", want: ""},
		{name: "direction glued to column", in: "pinned_desc", want: ""},
		{name: "column starts with digit", in: "1pinned desc", want: ""},
		{name: "dot qualifier", in: "yt_page.id desc", want: ""},
		{name: "hyphen", in: "pinned-at desc", want: ""},
		{name: "unicode column", in: "置顶 desc", want: ""},
		{name: "fullwidth comma", in: "pinned desc，weight desc", want: ""},
		{name: "star", in: "* desc", want: ""},
		{name: "function call", in: "count(*) desc", want: ""},
		{name: "parentheses", in: "id) desc", want: ""},
		{name: "single quote", in: "id' desc", want: ""},
		{name: "double quote", in: "id\" desc", want: ""},
		{name: "backslash", in: "id\\ desc", want: ""},
		{name: "null byte", in: "id\x00 desc", want: ""},
		{name: "semicolon", in: "id desc; drop table yt_page", want: ""},
		{name: "comment", in: "id desc--", want: ""},
		{name: "hash comment", in: "id desc#", want: ""},
		{name: "comma expression", in: "id DESC,extractvalue(1,concat(0x7e,user()))", want: ""},
		{name: "backtick breakout", in: "id`,extractvalue(1,concat(0x7e,user())) DESC", want: ""},
		{name: "space before breakout", in: "id desc, extractvalue(1,concat(0x7e,user()))", want: ""},
		{name: "newline payload", in: "id desc\nextractvalue()", want: ""},
		{name: "invalid direction", in: "pinned drop", want: ""},
		{name: "direction with junk", in: "pinned desc,", want: ""},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := ezSort(tt.in); got != tt.want {
				t.Fatalf("ezSort(%q) = %q, want %q", tt.in, got, tt.want)
			}
		})
	}
}