package com.seaofnodes.simple;

import com.seaofnodes.simple.codegen.CodeGen;
import org.junit.Ignore;
import org.junit.Test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

public class Chapter17bTest {

    @Ignore
    @Test
    public void testJig() {
        CodeGen code = new CodeGen(
"""
return 1;
""");
        code.parse().opto().typeCheck();
        assertEquals("return 1;", code.print());
        assertEquals("1", Eval2.eval(code,  0));
    }


    // ---------------------------------------------------------------
    @Test
    public void testInc0() {
        CodeGen code = new CodeGen("""
return arg++;
""");
        code.parse().opto();
        assertEquals("return arg;", code.print());
        assertEquals("0", Eval2.eval(code, 0));
    }

    @Test
    public void testInc1() {
        CodeGen code = new CodeGen("""
return arg+++arg++;
""");
        code.parse().opto();
        assertEquals("return ((arg<<1)+1);", code.print());
        assertEquals("1", Eval2.eval(code, 0));
    }

    @Test
    public void testInc2() {
        CodeGen code = new CodeGen("""
//   -(arg--)-(arg--)
return -arg---arg--;
""");
        code.parse().opto();
        assertEquals("return (-((arg<<1)+-1));", code.print());
        assertEquals("1", Eval2.eval(code, 0));
    }

    @Test
    public void testInc3() {
        CodeGen code = new CodeGen("""
int[] !xs = new int[arg];
xs[0]++;
xs[1]++;
return xs[0];
""");
        code.parse().opto();
        assertEquals("return 1;", code.print());
        assertEquals("1", Eval2.eval(code, 2));
    }

    @Test
    public void testInc4() {
        CodeGen code = new CodeGen("""
u8[] !xs = new u8[1];
xs[0]--;
return xs[0];
""");
        code.parse().opto();
        assertEquals("return 255;", code.print());
        assertEquals("255", Eval2.eval(code, 2));
    }

    @Test
    public void testInc5() {
        CodeGen code = new CodeGen("""
struct _S { u16 x; };
!_S !s = new _S;
s.x--;
return s.x;
""");
        code.parse().opto();
        assertEquals("return 65535;", code.print());
        assertEquals("65535", Eval2.eval(code, 2));
    }

    @Test
    public void testInc6() {
        CodeGen code = new CodeGen("return --arg;");
        code.parse().opto();
        assertEquals("return (arg+-1);", code.print());
        assertEquals("-1", Eval2.eval(code, 0));
    }

    @Test
    public void testInc7() {
        CodeGen code = new CodeGen("u8 x=0; return --x;");
        code.parse().opto();
        assertEquals("return 255;", code.print());
        assertEquals("255", Eval2.eval(code, 0));
    }

    @Test
    public void testInc8() {
        CodeGen code = new CodeGen("int x; x+=2; return x+=3;");
        code.parse().opto();
        assertEquals("return 5;", code.print());
        assertEquals("5", Eval2.eval(code, 0));
    }

    @Test
    public void testInc9() {
        CodeGen code = new CodeGen("flt x = 1.5; x++; return x;");
        code.parse().opto();
        assertEquals("return 2.5f;", code.print());
        assertEquals("2.5", Eval2.eval(code, 0));
    }

    @Test public void testInt10() {
        CodeGen code = new CodeGen("flt x = 1.5; x++; int i = x; return i;");
        code.parse().opto().typeCheck();
        assertEquals("2",Eval2.eval(code,0));
    }


    // ---------------------------------------------------------------
    @Test public void testVar0() {
        CodeGen code = new CodeGen("var d; return d;");
        try { code.parse().opto(); fail(); }
        catch( Exception e ) { assertEquals("Syntax error, expected `=expression` but found `;`",e.getMessage()); }
    }

    @Test public void testVar1() {
        CodeGen code = new CodeGen("val d; return d;");
        try { code.parse().opto(); fail(); }
        catch( Exception e ) { assertEquals("Syntax error, expected `=expression` but found `;`",e.getMessage()); }
    }

    @Test public void testVar2() {
        CodeGen code = new CodeGen("int x; x=3; x++; return x; // Ok, no initializer so x is mutable ");
        code.parse().opto();
        assertEquals("return 4;", code.print());
        assertEquals("4", Eval2.eval(code, 0));
    }

    @Test public void testVar3() {
        CodeGen code = new CodeGen("int x=3; x++; return x; // Ok, primitive so x is mutable despite initializer ");
        code.parse().opto();
        assertEquals("return 4;", code.print());
        assertEquals("4", Eval2.eval(code, 0));
    }

    @Test public void testVar4() {
        CodeGen code = new CodeGen("struct _S{int x;}; !_S? !s; s=new _S; s.x++; return s.x; // Ok, no initializer so x is mutable ");
        code.parse().opto();
        assertEquals("return 1;", code.print());
        assertEquals("1", Eval2.eval(code, 0));
    }

    @Test public void testVar5() {
        CodeGen code = new CodeGen("struct _S{int x; new _S={ int xx -> x=xx; };}; !_S? !s; s=new _S(3); s.x++; return s.x; // Ok, no initializer so x is mutable ");
        code.parse().opto();
        assertEquals("return 4;", code.print());
        assertEquals("4", Eval2.eval(code, 0));
    }

    @Test public void testVar6() {
        CodeGen code = new CodeGen("struct S{int x;}; ~S s = new S; s.x++; return s.x; // Error initializer so x is immutable ");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Cannot modify final field 'x'",e.getMessage()); }
    }

    @Test public void testVar7() {
        CodeGen code = new CodeGen("struct S{int x; new S={ int xx -> x=xx; };}; ~S s = new S(3); s.x++; return s.x; // Error initializer so x is immutable ");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Cannot modify final field 'x'",e.getMessage()); }
    }

    @Test public void testVar8() {
        CodeGen code = new CodeGen("struct _S{int x;}; !_S !s=new _S; s.x++; return s.x; // Ok, has '!' so s.x is mutable ");
        code.parse().opto();
        assertEquals("return 1;", code.print());
        assertEquals("1", Eval2.eval(code, 0));
    }

    @Test public void testVar9() {
        CodeGen code = new CodeGen("struct _S{int x;}; var s=new _S; s.x++; return s.x; // Ok, has var so s.x is mutable ");
        code.parse().opto();
        assertEquals("return 1;", code.print());
        assertEquals("1", Eval2.eval(code, 0));
    }

    @Test public void testVar10() {
        CodeGen code = new CodeGen("struct S{int x;}; ~S s=new S; s.x++; return s.x; // Error, has val so x is immutable ");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Cannot modify final field 'x'",e.getMessage()); }
    }

    @Test public void testVar11() {
        CodeGen code = new CodeGen("""
struct Bar { int x; };
!Bar !bar = new Bar;
bar.x = 3; // Ok, bar is mutable

struct Foo { !Bar? !bar; int y; new Foo = { !Bar? b -> bar = b; }; };
!Foo !foo = new Foo(bar);
foo.bar = bar; // Ok foo is mutable
foo.bar.x++;   // Ok foo and foo.bar and foo.bar.x are all mutable

~Foo xfoo = foo; // Throw away mutability
xfoo.bar.x++;   // Error, cannot mutate through xfoo
return xfoo.bar.x;
 """);
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Cannot modify final field 'x'",e.getMessage()); }
    }

    @Test public void testVar12() {
        CodeGen code = new CodeGen("""
struct _Bar { int x; };
!_Bar !bar = new _Bar;
bar.x = 3; // Ok, bar is mutable

struct _Foo { !_Bar? !bar; int y; };
!_Foo !foo = new _Foo;
foo.bar = bar; // Ok bar is mutable
foo.bar.x++;   // Ok foo and foo.bar and foo.bar.x are all mutable

~_Foo xfoo = foo;        // Throw away mutability
int x4 = xfoo.bar.x;   // Ok to read through xfoo, gets 4
foo.bar.x++;           // Bumps to 5
int x5 = xfoo.bar.x;   // Ok to read through xfoo, gets 5
return x4*10+x5;
""");
        code.parse().opto();
        assertEquals("return 45;", code.print());
        assertEquals("45", Eval2.eval(code, 0));
    }

    @Test
    public void testVar13() {
        CodeGen code = new CodeGen("""
int i,i++;
""");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Redefining name 'i'",e.getMessage()); }
    }


    @Test
    public void testVar14() {
        CodeGen code = new CodeGen("""
struct B {};
struct A { !B !b; new A = { ->
    return b; // read before init
    b = new B;
}; };
A x = new A;
""");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Field 'b' might not be initialized",e.getMessage()); }
    }

    @Test
    public void testVar15() {
        for( String fields : new String[] {
            "!B !b; new A = { -> if (arg) b = new B; };",
            "!B !b; new A = { -> if (arg) return 0; b = new B; };",
            "!B !b; new A = { !B b -> b = new B; };", // Argument shadows field
            "new A = { -> }; !B !b;",              // Field declared later
        } ) {
            CodeGen code = new CodeGen("struct B {}; struct A { "+fields+" }; return 0;");
            try { code.parse(); fail(fields); }
            catch( Parser.ParseException e ) { assertEquals("'Test.A' is not fully initialized, field 'b' is only partially set in the constructor",e.getMessage()); }
        }
    }

    @Test
    public void testDefaultConstructorFields() {
        for( String field : new String[] { "!B !b;", "!B !b;" } ) {
            CodeGen code = new CodeGen("struct B {}; struct A { "+field+" }; return new A;");
            try { code.parse(); fail(field); }
            catch( Parser.ParseException e ) { assertEquals("'Test.A' is not fully initialized, field 'b' needs to be set in a constructor",e.getMessage()); }
        }
        for( String fields : new String[] {
            "B b = new B;",
            "!B !b; b = new B;",
            "new A = { -> }; B b = new B;",
            "!B !b; new A = { -> if (arg) { b = new B; return 0; } b = new B; };",
        } ) {
            CodeGen code = new CodeGen("struct B {}; struct A { "+fields+" }; return new A.b != null;");
            code.parse().opto().typeCheck();
            assertEquals("1",Eval2.eval(code,0));
            assertEquals("1",Eval2.eval(code,1));
        }
        // No returning path means no object can escape uninitialized.
        new CodeGen("struct B {}; struct A { !B !b; new A = { -> while (true) {} }; }; return 0;").parse();
    }

    @Test
    public void testVar16() {
        CodeGen code = new CodeGen(
"""
struct S{ new S = { -> x = 2; }; };
val x = 1;
~S s = new S;
return x;
"""
);
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Undefined name 'x'",e.getMessage()); }
    }

    @Test
    public void testVar17() {
        CodeGen code = new CodeGen(
"""
struct Person {
    bool focused;
};
val focus = { !Person p ->
    p.focused = true;
};
!Person !me; // !Person !me = new Person;
focus(me);
return me;
"""
);
        try { code.parse(); fail(); }
        catch( Exception e ) { assertEquals("Syntax error, expected `=expression` but found `;`",e.getMessage()); }
    }

    // ---------------------------------------------------------------
    @Test
    public void testTrinary0() {
        CodeGen code = new CodeGen("""
return arg ? 1 : 2;
""");
        code.parse().opto();
        assertEquals("return Phi(Region,1,2);", code.print());
        assertEquals("2", Eval2.eval(code, 0));
        assertEquals("1", Eval2.eval(code, 1));
    }

    @Test
    public void testTrinary1() {
        CodeGen code = new CodeGen("""
return arg ? 0 : arg;
""");
        code.parse().opto();
        assertEquals("return 0;", code.print());
        assertEquals("0", Eval2.eval(code, 0));
    }

    @Test
    public void testShortCircuitGuard() {
        CodeGen code = new CodeGen("""
struct S { int !x; };
val get = { !S s -> s.x; };
!S? !s = arg ? new S;
if( !s || !arg ) return 0;
return get(s);
""");
        code.parse().opto().typeCheck();
    }

    @Test
    public void testTrinary2() {
        CodeGen code = new CodeGen("""
struct _Bar { int x; };
var b = arg ? new _Bar : null;
return b ? b.x++ + b.x++ : -1;
""");
        code.parse().opto();
        assertEquals("return Phi(Region,((.x<<1)+1),-1);", code.print());
        assertEquals("-1", Eval2.eval(code, 0));

                                   assertEquals("1", Eval2.eval(code, 1));
    }

    @Test
    public void testTrinary3() {
        CodeGen code = new CodeGen("""
struct _Bar { int x; };
var b = arg ? new _Bar;
return b ? b.x++ + b.x++ : -1;
""");
        code.parse().opto();
        assertEquals("return Phi(Region,((.x<<1)+1),-1);", code.print());
        assertEquals("-1", Eval2.eval(code, 0));
        assertEquals("1", Eval2.eval(code, 1));
    }

    @Test
    public void testTrinary4() {
        // This test case will benefit from an unzipping transformation
        CodeGen code = new CodeGen("""
struct _Bar { !_Bar? !next; int x; new _Bar = { !_Bar? !n, int xx -> next=n; x=xx; }; };
var b = arg ? new _Bar((arg==2) ? new _Bar(null,2), 1);
return b ? b.next ? b.next.x : b.x; // parses "b ? (b.next ? b.next.x : b.x) : 0"
""");
        code.parse().opto();
        assertEquals("return Phi(Region,.x,0,.x);", code.print());
        assertEquals("0", Eval2.eval(code, 0));
        assertEquals("1", Eval2.eval(code, 1));
        assertEquals("2", Eval2.eval(code, 2));
    }

    @Test
    public void testTrinary5() {
        CodeGen code = new CodeGen("""
flt f=arg?1:1.2;
return f;   // missing widening
""");
        code.parse().opto();
        assertEquals("return Phi(Region,1.0f,1.2);", code.print());
        assertEquals("1.2", Eval2.eval(code,  0));
    }


    @Test
    public void testTrinary6() {
        CodeGen code = new CodeGen("""
struct S{};
return arg ? 7 : new S;
""");
        try { code.parse().opto().typeCheck(); fail(); }
        catch( Exception e ) { assertEquals("Cannot return generic scalar",e.getMessage()); }
    }

    // ---------------------------------------------------------------
    @Test
    public void testFor0() {
        CodeGen code = new CodeGen("""
int sum=0;
for( int i=0; i<arg; i++ )
    sum += i;
return sum;
""");
        code.parse().opto();
        assertEquals("return Phi(Loop,0,(Phi_sum+Phi(Loop,0,(Phi_i+1))));", code.print());
        assertEquals("3", Eval2.eval(code, 3));
        assertEquals("45", Eval2.eval(code, 10));
    }
    @Test
    public void testFor1() {
        CodeGen code = new CodeGen("""
int sum=0, i=0;
for( ; i<arg; i++ )
    sum += i;
return sum;
""");
        code.parse().opto();
        assertEquals("return Phi(Loop,0,(Phi_sum+Phi(Loop,0,(Phi_i+1))));", code.print());
        assertEquals("3", Eval2.eval(code, 3));
        assertEquals("45", Eval2.eval(code, 10));
    }
    @Test
    public void testFor2() {
        CodeGen code = new CodeGen("""
int sum=0;
for( int i=0; ; i++ ) {
    if( i>=arg ) break;
    sum += i;
}
return sum;
""");
        code.parse().opto();
        assertEquals("return Phi(Loop,0,(Phi_sum+Phi(Loop,0,(Phi_i+1))));", code.print());
        assertEquals("3", Eval2.eval(code, 3));
        assertEquals("45", Eval2.eval(code, 10));
    }
    @Test
    public void testFor3() {
        CodeGen code = new CodeGen("""
int sum=0;
for( int i=0; i<arg; )
    sum += i++;
return sum;
""");
        code.parse().opto();
        assertEquals("return Phi(Loop,0,(Phi_sum+Phi(Loop,0,(Phi_i+1))));", code.print());
        assertEquals("3", Eval2.eval(code, 3));
        assertEquals("45", Eval2.eval(code, 10));
    }
    @Test
    public void testFor4() {
        CodeGen code = new CodeGen("""
int sum=0;
for( int i=0; i<arg; i++ )
    sum += i;
return i;
""");
        try { code.parse().opto(); fail(); }
        catch( Exception e ) { assertEquals("Undefined name 'i'",e.getMessage()); }
    }
    @Test
    public void testFor5() {
        CodeGen code = new CodeGen("""
for(;;arg++;) {}
""");
        try { code.parse().opto(); fail(); }
        catch( Exception e ) { assertEquals("Syntax error, expected `Unexpected code after expression` but found `;`",e.getMessage()); }
    }



    // ---------------------------------------------------------------
    @Test
    public void testForward0() {
        CodeGen code = new CodeGen("""
struct _A {
    !B? !f1;
    !B? !f2;
};
return new _A;
""");
        code.parse().opto();
        assertEquals("return Test._A;", code.print());
        assertEquals("Test._A{f1=null,f2=null}", Eval2.eval(code,0));
    }

    @Test
    public void testForward1() {
        CodeGen code = new CodeGen("""
struct _A {
    !B?[]? !nil_array_of_b;
    !B?[] !array_of_b;
    new _A = { !B?[] bs -> array_of_b = bs; };
};
return new _A(new !B?[0]).array_of_b;
""");
        code.parse().opto();
        assertEquals("return []*B?;", code.print());
        assertEquals("*B {}?[]", Eval2.eval(code,0));
    }

    // ---------------------------------------------------------------
    @Test
    public void testLinkedList2() {
        CodeGen code = new CodeGen("""
struct _LLI { !_LLI? !next; int i; new _LLI = { !_LLI? !n, int ii -> next=n; i=ii; }; };
!_LLI? !head = null;
while( arg-- )
    head = new _LLI(head,arg);
int sum=0;
var ptr = head; // A read-only ptr, to be assigned from read-only next fields
for( ; ptr; ptr = ptr.next )
    sum += ptr.i;
return sum;
""");
        code.parse().opto();
        assertEquals("return Phi(Loop,0,(Phi_sum+.i));", code.print());
        assertEquals("45", Eval2.eval(code, 10));
    }

    @Test
    public void sieveOfEratosthenes() {
        CodeGen code = new CodeGen(
"""
var ary = new bool[arg], primes = new int[arg];
var nprimes=0, p=0;
// Find primes while p^2 < arg
for( p=2; p*p < arg; p++ ) {
    // skip marked non-primes
    while( ary[p] ) p++;
    // p is now a prime
    primes[nprimes++] = p;
    // Mark out the rest non-primes
    for( int i = p + p; i < ary#; i += p )
        ary[i] = true;
}
// Now just collect the remaining primes, no more marking
for( ; p < arg; p++ )
    if( !ary[p] )
        primes[nprimes++] = p;
// Copy/shrink the result array
var !rez = new int[nprimes];
for( int j=0; j<nprimes; j++ )
    rez[j] = primes[j];
return rez;
""");
        code.parse().opto().typeCheck().GCM();
        assertEquals("return []i64;", code.print());
        assertEquals("i64[ 2,3,5,7,11,13,17,19]",Eval2.eval(code, 20));
    }

}