package store

import (
	"context"
	"testing"

	"gcy_hpc_server/internal/model"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

func newAppTestDB(t *testing.T) *gorm.DB {
	t.Helper()
	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		t.Fatalf("open sqlite: %v", err)
	}
	if err := db.AutoMigrate(&model.Application{}); err != nil {
		t.Fatalf("auto migrate: %v", err)
	}
	return db
}

func TestApplicationStore_Create_Success(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	id, err := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "gromacs",
		Description:    "Molecular dynamics simulator",
		Category:       "simulation",
		ScriptTemplate: "#!/bin/bash\nmodule load gromacs",
		Parameters:     []byte(`[{"name":"ntasks","type":"number","required":true}]`),
		Scope:          "system",
	})
	if err != nil {
		t.Fatalf("Create() error = %v", err)
	}
	if id <= 0 {
		t.Errorf("Create() id = %d, want positive", id)
	}
}

func TestApplicationStore_GetByID_Success(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	id, _ := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "lammps",
		ScriptTemplate: "#!/bin/bash\nmodule load lammps",
	})

	app, err := s.GetByID(context.Background(), id)
	if err != nil {
		t.Fatalf("GetByID() error = %v", err)
	}
	if app == nil {
		t.Fatal("GetByID() returned nil, expected application")
	}
	if app.Name != "lammps" {
		t.Errorf("Name = %q, want %q", app.Name, "lammps")
	}
	if app.ID != id {
		t.Errorf("ID = %d, want %d", app.ID, id)
	}
}

func TestApplicationStore_GetByID_NotFound(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	app, err := s.GetByID(context.Background(), 99999)
	if err != nil {
		t.Fatalf("GetByID() error = %v", err)
	}
	if app != nil {
		t.Error("GetByID() expected nil for not-found, got non-nil")
	}
}

func TestApplicationStore_List_Pagination(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	for i := 0; i < 5; i++ {
		s.Create(context.Background(), &model.CreateApplicationRequest{
			Name:           "app-" + string(rune('A'+i)),
			ScriptTemplate: "#!/bin/bash\necho " + string(rune('A'+i)),
		})
	}

	apps, total, err := s.List(context.Background(), 1, 3)
	if err != nil {
		t.Fatalf("List() error = %v", err)
	}
	if total != 5 {
		t.Errorf("total = %d, want 5", total)
	}
	if len(apps) != 3 {
		t.Errorf("len(apps) = %d, want 3", len(apps))
	}

	apps2, total2, err := s.List(context.Background(), 2, 3)
	if err != nil {
		t.Fatalf("List() page 2 error = %v", err)
	}
	if total2 != 5 {
		t.Errorf("total2 = %d, want 5", total2)
	}
	if len(apps2) != 2 {
		t.Errorf("len(apps2) = %d, want 2", len(apps2))
	}
}

func TestApplicationStore_Update_Success(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	id, _ := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "orig",
		ScriptTemplate: "#!/bin/bash\necho original",
	})

	newName := "updated"
	newDesc := "updated description"
	err := s.Update(context.Background(), id, &model.UpdateApplicationRequest{
		Name:        &newName,
		Description: &newDesc,
	})
	if err != nil {
		t.Fatalf("Update() error = %v", err)
	}

	app, _ := s.GetByID(context.Background(), id)
	if app.Name != "updated" {
		t.Errorf("Name = %q, want %q", app.Name, "updated")
	}
	if app.Description != "updated description" {
		t.Errorf("Description = %q, want %q", app.Description, "updated description")
	}
}

func TestApplicationStore_Update_NotFound(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	name := "nope"
	err := s.Update(context.Background(), 99999, &model.UpdateApplicationRequest{
		Name: &name,
	})
	if err == nil {
		t.Fatal("Update() expected error for not-found, got nil")
	}
}

func TestApplicationStore_Delete_Success(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	id, _ := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "to-delete",
		ScriptTemplate: "#!/bin/bash\necho bye",
	})

	err := s.Delete(context.Background(), id)
	if err != nil {
		t.Fatalf("Delete() error = %v", err)
	}

	app, _ := s.GetByID(context.Background(), id)
	if app != nil {
		t.Error("GetByID() after delete returned non-nil")
	}
}

func TestApplicationStore_Delete_Idempotent(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	err := s.Delete(context.Background(), 99999)
	if err != nil {
		t.Fatalf("Delete() non-existent error = %v, want nil (idempotent)", err)
	}
}

func TestApplicationStore_Create_DuplicateName(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	_, err := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "dup-app",
		ScriptTemplate: "#!/bin/bash\necho 1",
	})
	if err != nil {
		t.Fatalf("first Create() error = %v", err)
	}

	_, err = s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "dup-app",
		ScriptTemplate: "#!/bin/bash\necho 2",
	})
	if err == nil {
		t.Fatal("expected error for duplicate name, got nil")
	}
}

func TestApplicationStore_Create_EmptyParameters(t *testing.T) {
	db := newAppTestDB(t)
	s := NewApplicationStore(db)

	id, err := s.Create(context.Background(), &model.CreateApplicationRequest{
		Name:           "no-params",
		ScriptTemplate: "#!/bin/bash\necho hello",
	})
	if err != nil {
		t.Fatalf("Create() error = %v", err)
	}

	app, _ := s.GetByID(context.Background(), id)
	if string(app.Parameters) != "[]" {
		t.Errorf("Parameters = %q, want []", string(app.Parameters))
	}
}