/*
Copyright 2026 LocoStack.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package templates

import (
	"strings"
	"testing"

	"github.com/LocoStack/loco-operator/api/v1alpha1"
	corev1 "k8s.io/api/core/v1"
)

func TestResolveTemplateMergesBaseAndOverride(t *testing.T) {
	m := NewTemplateManager()
	m.RegisterTemplate(v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			NodeSelector: map[string]string{"zone": "a", "disk": "hdd"},
			Runtime: v1alpha1.RuntimeSpec{
				Name:  "go-runtime",
				Image: "golang:1.24",
				Port:  8080,
			},
		},
	})

	override := &v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			NodeSelector: map[string]string{"disk": "ssd"},
			Runtime: v1alpha1.RuntimeSpec{
				Image: "my-custom-image:1",
			},
		},
	}

	resolved, err := m.ResolveTemplate(override, "stack-default")
	if err != nil {
		t.Fatalf("expected no error, got %v", err)
	}

	if got := resolved.Spec.NodeSelector["zone"]; got != "a" {
		t.Fatalf("expected inherited nodeSelector zone, got %q", got)
	}
	if got := resolved.Spec.NodeSelector["disk"]; got != "ssd" {
		t.Fatalf("expected override nodeSelector disk, got %q", got)
	}
	if resolved.Spec.Runtime.Name != "go-runtime" {
		t.Fatalf("expected runtime name from base, got %q", resolved.Spec.Runtime.Name)
	}
	if resolved.Spec.Runtime.Image != "my-custom-image:1" {
		t.Fatalf("expected runtime image override, got %q", resolved.Spec.Runtime.Image)
	}
	if resolved.Spec.Runtime.Port != 8080 {
		t.Fatalf("expected inherited runtime port, got %d", resolved.Spec.Runtime.Port)
	}
}

func TestResolveTemplateErrorsWhenTemplateMissing(t *testing.T) {
	m := NewTemplateManager()

	_, err := m.ResolveTemplate(&v1alpha1.Template{Name: "missing-template"}, "stack-default")
	if err == nil {
		t.Fatalf("expected error for missing template")
	}
	if !strings.Contains(err.Error(), "template \"missing-template\" not found") {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestResolveTemplateErrorsWhenRuntimeMissing(t *testing.T) {
	m := NewTemplateManager()
	m.RegisterTemplate(v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			Runtime: v1alpha1.RuntimeSpec{Name: "go-runtime"},
		},
	})

	_, err := m.ResolveTemplate(&v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			Runtime: v1alpha1.RuntimeSpec{Name: "python-runtime"},
		},
	}, "stack-default")
	if err == nil {
		t.Fatalf("expected error for missing runtime")
	}
	if !strings.Contains(err.Error(), "runtime \"python-runtime\" not found") {
		t.Fatalf("unexpected error: %v", err)
	}
}

func TestResolveTemplateResolvesRuntimePresetAndMergesOverride(t *testing.T) {
	m := NewTemplateManager()
	m.RegisterTemplate(v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			Runtime: v1alpha1.RuntimeSpec{Name: "go-runtime", Image: "golang:1.24"},
		},
	})
	m.RegisterRuntime(v1alpha1.RuntimeSpec{
		Name:      "python-runtime",
		Image:     "python:3.12",
		Command:   []string{"python"},
		ExtraArgs: []string{"-m", "http.server"},
		Env:       []corev1.EnvVar{{Name: "BASE", Value: "1"}},
		Port:      8000,
	})

	override := &v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			Runtime: v1alpha1.RuntimeSpec{
				Name:  "python-runtime",
				Image: "python:3.12-slim",
				Args:  []string{"-u"},
				Env:   []corev1.EnvVar{{Name: "OVERRIDE", Value: "2"}},
			},
		},
	}

	resolved, err := m.ResolveTemplate(override, "stack-default")
	if err != nil {
		t.Fatalf("expected no error, got %v", err)
	}

	if resolved.Spec.Runtime.Name != "python-runtime" {
		t.Fatalf("expected resolved runtime name, got %q", resolved.Spec.Runtime.Name)
	}
	if resolved.Spec.Runtime.Image != "python:3.12-slim" {
		t.Fatalf("expected override image on resolved runtime, got %q", resolved.Spec.Runtime.Image)
	}
	if len(resolved.Spec.Runtime.Command) != 1 || resolved.Spec.Runtime.Command[0] != "python" {
		t.Fatalf("expected inherited command from runtime preset")
	}
	if len(resolved.Spec.Runtime.ExtraArgs) != 2 || resolved.Spec.Runtime.ExtraArgs[0] != "-m" {
		t.Fatalf("expected inherited extraArgs from runtime preset")
	}
	if len(resolved.Spec.Runtime.Args) != 1 || resolved.Spec.Runtime.Args[0] != "-u" {
		t.Fatalf("expected override args on resolved runtime")
	}
	if len(resolved.Spec.Runtime.Env) != 1 || resolved.Spec.Runtime.Env[0].Name != "OVERRIDE" {
		t.Fatalf("expected override env on resolved runtime")
	}
	if resolved.Spec.Runtime.Port != 8000 {
		t.Fatalf("expected inherited port from runtime preset, got %d", resolved.Spec.Runtime.Port)
	}
}

func TestResolveTemplateWithoutNameUsesDefaultTemplate(t *testing.T) {
	m := NewTemplateManager()
	m.RegisterTemplate(v1alpha1.Template{
		Name: "stack-default",
		Spec: v1alpha1.TemplateSpec{
			NodeSelector: map[string]string{"zone": "a", "disk": "hdd"},
		},
	})

	in := &v1alpha1.Template{
		Spec: v1alpha1.TemplateSpec{
			NodeSelector: map[string]string{"disk": "ssd"},
		},
	}

	resolved, err := m.ResolveTemplate(in, "stack-default")
	if err != nil {
		t.Fatalf("expected no error, got %v", err)
	}
	if got := resolved.Spec.NodeSelector["zone"]; got != "a" {
		t.Fatalf("expected nodeSelector zone from default template, got %q", got)
	}
	if got := resolved.Spec.NodeSelector["disk"]; got != "ssd" {
		t.Fatalf("expected nodeSelector disk override from input template, got %q", got)
	}
}