package eval_test

import (
	"testing"

	. "github.com/elves/elvish/pkg/eval"
	"github.com/elves/elvish/pkg/eval/errs"
	"github.com/elves/elvish/pkg/testutil"

	. "github.com/elves/elvish/pkg/eval/evaltest"
	"github.com/elves/elvish/pkg/eval/vals"
)

func TestCompound(t *testing.T) {
	Test(t,
		That("put {fi,elvi}sh{1.0,1.1}").Puts(
			"fish1.0", "fish1.1", "elvish1.0", "elvish1.1"),

		// As a special case, an empty compound expression evaluates to an empty
		// string.
		That("put {}").Puts(""),
		That("put [&k=][k]").Puts(""),

		// TODO: Test the case where fsutil.GetHome returns an error.

		// Error in any of the components throws an exception.
		That("put a{[][1]}").Throws(ErrorWithType(errs.OutOfRange{}), "[][1]"),
		// Error in concatenating the values throws an exception.
		That("put []a").Throws(ErrorWithMessage("cannot concatenate list and string")),
		// Error when applying tilde throws an exception.
		That("put ~[]").Throws(ErrorWithMessage("tilde doesn't work on value of type list")),
	)
}

func TestIndexing(t *testing.T) {
	Test(t,
		That("put [a b c][2]").Puts("c"),
		That("put [][0]").Throws(ErrorWithType(errs.OutOfRange{}), "[][0]"),
		That("put [&key=value][key]").Puts("value"),
		That("put [&key=value][bad]").Throws(
			vals.NoSuchKey("bad"), "[&key=value][bad]"),
	)
}

func TestListLiteral(t *testing.T) {
	Test(t,
		That("put [a b c]").Puts(vals.MakeList("a", "b", "c")),
		That("put []").Puts(vals.EmptyList),
		// List expression errors if an element expression errors.
		That("put [ [][0] ]").Throws(ErrorWithType(errs.OutOfRange{}), "[][0]"),
	)
}

func TestMapLiteral(t *testing.T) {
	Test(t,
		That("put [&key=value]").Puts(vals.MakeMap("key", "value")),
		That("put [&]").Puts(vals.EmptyMap),
		// Map keys and values may evaluate to multiple values as long as their
		// numbers match.
		That("put [&{a b}={foo bar}]").Puts(vals.MakeMap("a", "foo", "b", "bar")),
		// Map expression errors if a key or value expression errors.
		That("put [ &[][0]=a ]").Throws(ErrorWithType(errs.OutOfRange{}), "[][0]"),
		That("put [ &a=[][0] ]").Throws(ErrorWithType(errs.OutOfRange{}), "[][0]"),
		// Map expression errors if number of keys and values in a single pair
		// does not match.
		That("put [&{a b}={foo bar lorem}]").Throws(ErrorWithMessage("2 keys but 3 values")),
	)
}

func TestStringLiteral(t *testing.T) {
	Test(t,
		That(`put 'such \"''literal'`).Puts(`such \"'literal`),
		That(`put "much \n\033[31;1m$cool\033[m"`).
			Puts("much \n\033[31;1m$cool\033[m"),
	)
}

func TestTilde(t *testing.T) {
	home, cleanup := testutil.InTempHome()
	testutil.MustCreateEmpty("file1")
	testutil.MustCreateEmpty("file2")
	defer cleanup()

	Test(t,
		// Tilde
		// -----
		That("put ~").Puts(home),
		That("put ~/src").Puts(home+"/src"),
		// Make sure that tilde processing retains trailing slashes.
		That("put ~/src/").Puts(home+"/src/"),
		// Tilde and wildcard.
		That("put ~/*").Puts(home+"/file1", home+"/file2"),
		// TODO(xiaq): Add regression test for #793.
	)
}

func TestOutputCapture(t *testing.T) {
	Test(t,
		// Output capture
		That("put (put lorem ipsum)").Puts("lorem", "ipsum"),
		That("put (print \"lorem\nipsum\")").Puts("lorem", "ipsum"),
		// \r\n is also supported as a line separator
		That(`print "lorem\r\nipsum\r\n" | all`).Puts("lorem", "ipsum"),
	)
}

func TestExceptionCapture(t *testing.T) {
	Test(t,
		// Exception capture
		That("bool ?(nop); bool ?(e:false)").Puts(true, false),
	)
}

func TestVariableUse(t *testing.T) {
	Test(t,
		That("x = foo", "put $x").Puts("foo"),
		// Must exist before use
		That("put $x").DoesNotCompile(),
		That("put $x[0]").DoesNotCompile(),
		// Compounding
		That("x = SHELL", "put 'WOW, SUCH '$x', MUCH COOL'\n").
			Puts("WOW, SUCH SHELL, MUCH COOL"),
		// Splicing
		That("x = [elvish rules]", "put $@x").Puts("elvish", "rules"),

		// Variable namespace
		// ------------------

		// Pseudo-namespace local: accesses the local scope.
		That("x = outer; { local:x = inner; put $local:x }").Puts("inner"),
		// Pseudo-namespace up: accesses upvalues.
		That("x = outer; { local:x = inner; put $up:x }").Puts("outer"),
		// Pseudo-namespace builtin: accesses builtins.
		That("put $builtin:true").Puts(true),
		// Unqualified name prefers local: to up:.
		That("x = outer; { local:x = inner; put $x }").Puts("inner"),
		// Unqualified name resolves to upvalue if no local name exists.
		That("x = outer; { put $x }").Puts("outer"),
		// Unqualified name resolves to builtin if no local name or upvalue
		// exists.
		That("put $true").Puts(true),
		// A name can be explicitly unqualified by having a leading colon.
		That("x = val; put $:x").Puts("val"),
		That("put $:true").Puts(true),

		// Pseudo-namespace E: provides read-write access to environment
		// variables. Colons inside the name are supported.
		That("set-env a:b VAL; put $E:a:b").Puts("VAL"),
		That("E:a:b = VAL2; get-env a:b").Puts("VAL2"),

		// Pseudo-namespace e: provides readonly access to external commands.
		// Only names ending in ~ are resolved, and resolution always succeeds
		// regardless of whether the command actually exists. Colons inside the
		// name are supported.
		That("put $e:a:b~").Puts(NewExternalCmd("a:b")),

		// A "normal" namespace access indexes the namespace as a variable.
		That("ns: = (ns [&a= val]); put $ns:a").Puts("val"),
		// Multi-level namespace access is supported.
		That("ns: = (ns [&a:= (ns [&b= val])]); put $ns:a:b").Puts("val"),
		// Multi-level namespace access can have a leading colon to signal that
		// the first component is unqualified.
		That("ns: = (ns [&a:= (ns [&b= val])]); put $:ns:a:b").Puts("val"),
		// Multi-level namespace access can be combined with the local:
		// pseudo-namespaces.
		That("ns: = (ns [&a:= (ns [&b= val])]); put $local:ns:a:b").Puts("val"),
		// Multi-level namespace access can be combined with the up:
		// pseudo-namespaces.
		That("ns: = (ns [&a:= (ns [&b= val])]); { put $up:ns:a:b }").Puts("val"),
	)
}

func TestClosure(t *testing.T) {
	Test(t,
		That("[]{ }").DoesNothing(),
		That("[x]{put $x} foo").Puts("foo"),

		// Assigning to captured variable
		That("x=lorem; []{x=ipsum}; put $x").Puts("ipsum"),
		That("x=lorem; []{ put $x; x=ipsum }; put $x").Puts("lorem", "ipsum"),

		// Assigning to element of captured variable
		That("x = a; { x = b }; put $x").Puts("b"),
		That("x = [a]; { x[0] = b }; put $x[0]").Puts("b"),

		// Shadowing
		That("x=ipsum; []{ local:x=lorem; put $x }; put $x").Puts("lorem", "ipsum"),

		// Shadowing by argument
		That("x=ipsum; [x]{ put $x; x=BAD } lorem; put $x").Puts("lorem", "ipsum"),

		// Closure captures new local variables every time
		That(`fn f []{ x=0; put []{x=(+ $x 1)} []{put $x} }
		  {inc1,put1}=(f); $put1; $inc1; $put1
		  {inc2,put2}=(f); $put2; $inc2; $put2`).Puts("0", 1.0, "0", 1.0),

		// Rest argument.
		That("[x @xs]{ put $x $xs } a b c").Puts("a", vals.MakeList("b", "c")),
		That("[a @b c]{ put $a $b $c } a b c d").
			Puts("a", vals.MakeList("b", "c"), "d"),
		// Options.
		That("[a &k=v]{ put $a $k } foo &k=bar").Puts("foo", "bar"),
		// Option default value.
		That("[a &k=v]{ put $a $k } foo").Puts("foo", "v"),

		// Argument name must be unqualified.
		That("[a:b]{ }").DoesNotCompile(),
		// Argument name must not be empty.
		That("['']{ }").DoesNotCompile(),
		That("[@]{ }").DoesNotCompile(),
		// Option name must be unqualified.
		That("[&a:b=1]{ }").DoesNotCompile(),
		// Option name must not be empty.
		That("[&''=b]{ }").DoesNotCompile(),

		// Exception when evaluating option default value.
		That("[&a=[][0]]{ }").Throws(ErrorWithType(errs.OutOfRange{}), "[][0]"),
		// Option default value must be one value.
		That("[&a=(put foo bar)]{ }").Throws(
			errs.ArityMismatch{
				What: "option default value", ValidLow: 1, ValidHigh: 1, Actual: 2},
			"(put foo bar)"),
	)
}