package analyzer

import (
	"five/compiler/parser"
	"strings"
	"testing"
)

func analyze(t *testing.T, source string) []Diagnostic {
	t.Helper()
	file, errs := parser.Parse("test.prg", source)
	if len(errs) > 0 {
		t.Fatalf("parse error: %s", errs[0])
	}
	return Analyze(file)
}

func TestCleanCode(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL cName, nAge
   cName := "Charles"
   nAge := 30
   ? cName, nAge
   RETURN
`)
	for _, d := range diags {
		if d.Severity == SevError || d.Severity == SevWarning {
			t.Errorf("unexpected diagnostic: %s", d)
		}
	}
}

func TestUndeclaredVariable(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL cName
   cName := "Charles"
   ? cName, nAge
   RETURN
`)
	found := false
	for _, d := range diags {
		if strings.Contains(d.Message, "undeclared") && strings.Contains(d.Message, "nAge") {
			found = true
		}
	}
	if !found {
		t.Error("expected 'undeclared variable nAge' warning")
	}
}

func TestUnusedVariable(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL cUsed, cNeverTouched
   cUsed := "hello"
   ? cUsed
   RETURN
`)
	found := false
	for _, d := range diags {
		if strings.Contains(d.Message, "unused") && strings.Contains(d.Message, "cNeverTouched") {
			found = true
		}
	}
	if !found {
		t.Error("expected 'unused variable cNeverTouched' hint")
	}
}

func TestParamsDeclared(t *testing.T) {
	diags := analyze(t, `
FUNCTION Add(a, b)
   LOCAL nResult
   nResult := a + b
   RETURN nResult
`)
	for _, d := range diags {
		if d.Severity == SevError || d.Severity == SevWarning {
			t.Errorf("unexpected: %s", d)
		}
	}
}

func TestMultiFunction(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL n
   n := GetValue()
   ? n
   RETURN

FUNCTION GetValue()
   LOCAL x
   x := 42
   RETURN x
`)
	for _, d := range diags {
		if d.Severity == SevWarning {
			t.Errorf("unexpected warning: %s", d)
		}
	}
}

func TestForLoopVar(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL i, aData
   aData := {1, 2, 3}
   FOR i := 1 TO Len(aData)
      ? aData[i]
   NEXT
   RETURN
`)
	for _, d := range diags {
		if d.Severity == SevWarning {
			t.Errorf("unexpected: %s", d)
		}
	}
}

func TestMultiAssignDeclared(t *testing.T) {
	diags := analyze(t, `
PROCEDURE Main()
   LOCAL cName, nAge
   cName, nAge := "Charles", 30
   ? cName, nAge
   RETURN
`)
	for _, d := range diags {
		if d.Severity == SevWarning {
			t.Errorf("unexpected: %s", d)
		}
	}
}