Dragon-Knight/internal/monsters/monsters.go

package monsters

import (
	"fmt"

	"dk/internal/database"
	"dk/internal/helpers/scanner"

	"zombiezen.com/go/sqlite"
)

// Monster represents a monster in the database
type Monster struct {
	database.BaseModel

	ID      int    `db:"id" json:"id"`
	Name    string `db:"name" json:"name"`
	MaxHP   int    `db:"max_hp" json:"max_hp"`
	MaxDmg  int    `db:"max_dmg" json:"max_dmg"`
	Armor   int    `db:"armor" json:"armor"`
	Level   int    `db:"level" json:"level"`
	MaxExp  int    `db:"max_exp" json:"max_exp"`
	MaxGold int    `db:"max_gold" json:"max_gold"`
	Immune  int    `db:"immune" json:"immune"`
}

func (m *Monster) GetTableName() string {
	return "monsters"
}

func (m *Monster) GetID() int {
	return m.ID
}

func (m *Monster) SetID(id int) {
	m.ID = id
}

func (m *Monster) Set(field string, value any) error {
	return database.Set(m, field, value)
}

func (m *Monster) Save() error {
	return database.Save(m)
}

func (m *Monster) Delete() error {
	return database.Delete(m)
}

// Creates a new Monster with sensible defaults
func New() *Monster {
	return &Monster{
		Name:    "",
		MaxHP:   10,         // Default HP
		MaxDmg:  5,          // Default damage
		Armor:   0,          // Default armor
		Level:   1,          // Default level
		MaxExp:  10,         // Default exp reward
		MaxGold: 5,          // Default gold reward
		Immune:  ImmuneNone, // No immunity by default
	}
}

var monsterScanner = scanner.New[Monster]()

// Returns the column list for monster queries
func monsterColumns() string {
	return monsterScanner.Columns()
}

// Populates a Monster struct using the fast scanner
func scanMonster(stmt *sqlite.Stmt) *Monster {
	monster := &Monster{}
	monsterScanner.Scan(stmt, monster)
	return monster
}

// Immunity constants for monster immunity types
const (
	ImmuneNone  = 0
	ImmuneHurt  = 1 // Immune to Hurt spells
	ImmuneSleep = 2 // Immune to Sleep spells
)

// Retrieves a monster by ID
func Find(id int) (*Monster, error) {
	var monster *Monster

	query := `SELECT ` + monsterColumns() + ` FROM monsters WHERE id = ?`

	err := database.Query(query, func(stmt *sqlite.Stmt) error {
		monster = scanMonster(stmt)
		return nil
	}, id)

	if err != nil {
		return nil, fmt.Errorf("failed to find monster: %w", err)
	}

	if monster == nil {
		return nil, fmt.Errorf("monster with ID %d not found", id)
	}

	return monster, nil
}

// Retrieves all monsters
func All() ([]*Monster, error) {
	var monsters []*Monster

	query := `SELECT ` + monsterColumns() + ` FROM monsters ORDER BY level, id`

	err := database.Query(query, func(stmt *sqlite.Stmt) error {
		monster := scanMonster(stmt)
		monsters = append(monsters, monster)
		return nil
	})

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve all monsters: %w", err)
	}

	return monsters, nil
}

// Retrieves monsters by level
func ByLevel(level int) ([]*Monster, error) {
	var monsters []*Monster

	query := `SELECT ` + monsterColumns() + ` FROM monsters WHERE level = ? ORDER BY id`

	err := database.Query(query, func(stmt *sqlite.Stmt) error {
		monster := scanMonster(stmt)
		monsters = append(monsters, monster)
		return nil
	}, level)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve monsters by level: %w", err)
	}

	return monsters, nil
}

// Retrieves monsters within a level range (inclusive)
func ByLevelRange(minLevel, maxLevel int) ([]*Monster, error) {
	var monsters []*Monster

	query := `SELECT ` + monsterColumns() + ` FROM monsters WHERE level BETWEEN ? AND ? ORDER BY level, id`

	err := database.Query(query, func(stmt *sqlite.Stmt) error {
		monster := scanMonster(stmt)
		monsters = append(monsters, monster)
		return nil
	}, minLevel, maxLevel)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve monsters by level range: %w", err)
	}

	return monsters, nil
}

// Retrieves monsters by immunity type
func ByImmunity(immunityType int) ([]*Monster, error) {
	var monsters []*Monster

	query := `SELECT ` + monsterColumns() + ` FROM monsters WHERE immune = ? ORDER BY level, id`

	err := database.Query(query, func(stmt *sqlite.Stmt) error {
		monster := scanMonster(stmt)
		monsters = append(monsters, monster)
		return nil
	}, immunityType)

	if err != nil {
		return nil, fmt.Errorf("failed to retrieve monsters by immunity: %w", err)
	}

	return monsters, nil
}

// Saves a new monster to the database and sets the ID
func (m *Monster) Insert() error {
	columns := `name, max_hp, max_dmg, armor, level, max_exp, max_gold, immune`
	values := []any{m.Name, m.MaxHP, m.MaxDmg, m.Armor, m.Level, m.MaxExp, m.MaxGold, m.Immune}
	return database.Insert(m, columns, values...)
}

// Returns true if the monster is immune to Hurt spells
func (m *Monster) IsHurtImmune() bool {
	return m.Immune == ImmuneHurt
}

// Returns true if the monster is immune to Sleep spells
func (m *Monster) IsSleepImmune() bool {
	return m.Immune == ImmuneSleep
}

// Returns true if the monster has any immunity
func (m *Monster) HasImmunity() bool {
	return m.Immune != ImmuneNone
}

// Returns the string representation of the monster's immunity
func (m *Monster) ImmunityName() string {
	switch m.Immune {
	case ImmuneNone:
		return "None"
	case ImmuneHurt:
		return "Hurt Spells"
	case ImmuneSleep:
		return "Sleep Spells"
	default:
		return "Unknown"
	}
}

// Calculates a simple difficulty rating based on stats
func (m *Monster) DifficultyRating() float64 {
	// Simple formula: (HP + Damage + Armor) / Level
	// Higher values indicate tougher monsters relative to their level
	if m.Level == 0 {
		return 0
	}
	return float64(m.MaxHP+m.MaxDmg+m.Armor) / float64(m.Level)
}

// Returns the experience reward per hit point (efficiency metric)
func (m *Monster) ExpPerHP() float64 {
	if m.MaxHP == 0 {
		return 0
	}
	return float64(m.MaxExp) / float64(m.MaxHP)
}

// Returns the gold reward per hit point (efficiency metric)
func (m *Monster) GoldPerHP() float64 {
	if m.MaxHP == 0 {
		return 0
	}
	return float64(m.MaxGold) / float64(m.MaxHP)
}