#include "spec_helper.h"
#include "transitions.h"

START_TEST

describe("Rules", []() {
    rules::rule_ptr symbol1 = rules::sym("1");
    rules::rule_ptr symbol2 = rules::sym("2");
    rules::rule_ptr symbol3 = rules::sym("3");
    rules::rule_ptr symbol4 = rules::sym("4");
    rules::rule_ptr char1 = rules::character('a');
    
    describe("construction", [&]() {
        it("constructs binary trees", [&]() {
            AssertThat(
                rules::seq({ symbol1, symbol2, symbol3 }),
                EqualsPointer(
                    rules::seq({ rules::seq({ symbol1, symbol2 }), symbol3 })));

            AssertThat(
                rules::choice({ symbol1, symbol2, symbol3 }),
                EqualsPointer(
                    rules::choice({ rules::choice({ symbol1, symbol2 }), symbol3 })));
        });
    });
    
    describe("transitions", [&]() {
        it("handles symbols", [&]() {
            AssertThat(
                rules::transitions(symbol1),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { symbol1, rules::blank() }
                })));
        });

        it("handles characters", [&]() {
            AssertThat(
                rules::transitions(char1),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { char1, rules::blank() }
                })));
        });

        it("handles character classes", [&]() {
            auto rule = rules::character(CharClassDigit);
            AssertThat(
                rules::transitions(rule),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { rule, rules::blank() }
                })));
        });

        it("handles choices", [&]() {
            AssertThat(
                rules::transitions(rules::choice({ symbol1, symbol2 })),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { symbol1, rules::blank() },
                    { symbol2, rules::blank() }
                })));
        });

        it("handles sequences", [&]() {
            AssertThat(
                rules::transitions(rules::seq({ symbol1, symbol2 })),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { symbol1, symbol2 }
                })));
        });

        it("handles_long_sequences", [&]() {
            AssertThat(
                rules::transitions(rules::seq({
                    symbol1,
                    symbol2,
                    symbol3,
                    symbol4
                })),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { symbol1, rules::seq({ symbol2, symbol3, symbol4 }) }
                })));
        });

        it("handles choices with common starting symbols", [&]() {
            AssertThat(
                rules::transitions(
                    rules::choice({
                        rules::seq({ symbol1, symbol2 }),
                        rules::seq({ symbol1, symbol3 }) })),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { symbol1, rules::choice({ symbol2, symbol3 }) }
                })));
        });

        it("handles strings", [&]() {
            AssertThat(
                rules::transitions(rules::str("bad")),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    {
                        rules::character('b'),
                        rules::seq({ rules::character('a'), rules::character('d') })
                    }
                })));
        });

        it("handles patterns", [&]() {
            AssertThat(
                rules::transitions(rules::pattern("a|b")),
                Equals(transition_map<rules::Rule, rules::Rule>({
                    { rules::character('a'), rules::blank() },
                    { rules::character('b'), rules::blank() }
                })));
        });
        
        it("handles repeats", [&]() {
            rules::rule_ptr repeat = rules::repeat(rules::str("ab"));
            AssertThat(
                rules::transitions(repeat),
                Equals(transition_map<rules::Rule, rules::Rule>({
                {
                    rules::character('a'),
                    rules::seq({
                        rules::character('b'),
                        rules::choice({
                            repeat,
                            rules::blank()
                        })
                    })
                }})));
            
            repeat = rules::repeat(rules::str("a"));
            AssertThat(
                rules::transitions(repeat),
                Equals(transition_map<rules::Rule, rules::Rule>({
                {
                    rules::character('a'),
                    rules::choice({
                        repeat,
                        rules::blank()
                    })
                }})));
        });
    });
});

END_TEST