package dsl

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func writeTempJdg(t *testing.T, dir, name, content string) string {
	t.Helper()
	path := filepath.Join(dir, name)
	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
		t.Fatal(err)
	}
	return path
}

func TestIncludeBasicMerge(t *testing.T) {
	dir := t.TempDir()

	writeTempJdg(t, dir, "common.jdg", `
toolchains {
    gcc { platforms = "linux" }
}

build_defaults {
    language = "c"
    standard = "c11"
    sources  = "*.c"
    output   = "solution"
    warnings = strict
}
`)

	mainPath := writeTempJdg(t, dir, "main.jdg", `
include "common.jdg"

build "release" { profile = release }

group("g") {
    weight = 1.0
    test("t") { stdout = "ok\n" }
}
`)

	f, _, err := ParseFile(mainPath)
	if err != nil {
		t.Fatalf("parse: %v", err)
	}

	if len(f.Toolchains) != 1 || f.Toolchains[0].Name != "gcc" {
		t.Errorf("toolchains not merged: %+v", f.Toolchains)
	}
	if f.BuildDefaults == nil || f.BuildDefaults.Language != "c" {
		t.Errorf("build_defaults not merged: %+v", f.BuildDefaults)
	}
	if len(f.Builds) != 1 || f.Builds[0].Name != "release" {
		t.Errorf("local build lost: %+v", f.Builds)
	}
}

func TestIncludeLocalOverridesIncluded(t *testing.T) {
	dir := t.TempDir()

	writeTempJdg(t, dir, "common.jdg", `
build_defaults {
    language = "c"
    standard = "c11"
    warnings = strict
}
`)

	mainPath := writeTempJdg(t, dir, "main.jdg", `
include "common.jdg"

build_defaults {
    standard = "c17"
}

group("g") { weight = 1.0 test("t") { stdout = "ok\n" } }
`)

	f, _, err := ParseFile(mainPath)
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if f.BuildDefaults.Standard != "c17" {
		t.Errorf("local should override included standard: got %q", f.BuildDefaults.Standard)
	}
	if f.BuildDefaults.Language != "c" {
		t.Errorf("language should survive from include: got %q", f.BuildDefaults.Language)
	}
	if f.BuildDefaults.Warnings != WarningsStrict {
		t.Errorf("warnings should survive from include: got %v", f.BuildDefaults.Warnings)
	}
}

func TestIncludeRelativePathResolution(t *testing.T) {
	dir := t.TempDir()

	writeTempJdg(t, dir, "shared/tools.jdg", `
toolchains {
    gcc { platforms = "linux" }
}
`)

	mainPath := writeTempJdg(t, dir, "suite/main.jdg", `
include "../shared/tools.jdg"

build "release" {
    language = "c"
    sources  = "solution.c"
    output   = "solution"
    profile  = release
}

group("g") { weight = 1.0 test("t") { stdout = "ok\n" } }
`)

	f, _, err := ParseFile(mainPath)
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if len(f.Toolchains) != 1 {
		t.Errorf("relative include failed to resolve: %+v", f.Toolchains)
	}
}

func TestIncludeDuplicateToolchainErrors(t *testing.T) {
	dir := t.TempDir()

	writeTempJdg(t, dir, "common.jdg", `
toolchains {
    gcc { platforms = "linux" }
}
`)

	mainPath := writeTempJdg(t, dir, "main.jdg", `
include "common.jdg"

toolchains {
    gcc { platforms = "linux" }
}

group("g") { weight = 1.0 test("t") { stdout = "ok\n" } }
`)

	_, _, err := ParseFile(mainPath)
	if err == nil {
		t.Fatal("expected duplicate toolchain error")
	}
	if !strings.Contains(err.Error(), "duplicate toolchain") {
		t.Errorf("error %q does not mention duplicate toolchain", err.Error())
	}
}

func TestIncludeCircularDetection(t *testing.T) {
	dir := t.TempDir()

	aPath := writeTempJdg(t, dir, "a.jdg", `
include "b.jdg"
group("ga") { weight = 1.0 test("t") { stdout = "ok\n" } }
`)
	writeTempJdg(t, dir, "b.jdg", `
include "a.jdg"
`)

	_, _, err := ParseFile(aPath)
	if err == nil {
		t.Fatal("expected circular include error")
	}
	if !strings.Contains(err.Error(), "circular include") {
		t.Errorf("error %q does not mention circular include", err.Error())
	}
}

func TestIncludeMissingFileErrors(t *testing.T) {
	dir := t.TempDir()

	mainPath := writeTempJdg(t, dir, "main.jdg", `
include "nonexistent.jdg"
group("g") { weight = 1.0 test("t") { stdout = "ok\n" } }
`)

	_, _, err := ParseFile(mainPath)
	if err == nil {
		t.Fatal("expected missing include error")
	}
	if !strings.Contains(err.Error(), "nonexistent.jdg") {
		t.Errorf("error %q does not reference the missing path", err.Error())
	}
}

func TestParseRejectsIncludeWithoutFileContext(t *testing.T) {
	src := `
include "common.jdg"
group("g") { weight = 1.0 test("t") { stdout = "ok\n" } }
`
	_, _, err := Parse(src)
	if err == nil {
		t.Fatal("expected error: include without file context")
	}
	if !strings.Contains(err.Error(), "file context") {
		t.Errorf("error %q does not mention file context", err.Error())
	}
}