// Package loader loads persona definitions from YAML files using gopkg.in/yaml.v3.
// A persona is the self-awareness/identity bound to a character and, per
// DevDocs/design/01, it also carries the emotion state-machine parameters, the
// affection curve, and a per-persona memory namespace (memory isolation).
package loader

import (
	"git.yeij.top/AskaEth/Cyrene_v2/internal/persona/emotion"
)

// Default affection bounds and step, applied when a persona defines no
// affection curve.
const (
	defaultAffectionMin   = 0
	defaultAffectionMax   = 100
	defaultAffectionInit  = 50
	defaultAffectionDelta = 5
)

// defaultMemoryNS is the namespace prefix used when a persona omits a concrete
// memory namespace; the full namespace becomes prefix + "." + persona id.
const defaultMemoryNS = "persona"

// Identity is the persona's self-awareness: the 人设 (who she is, e.g. a
// character role) plus the system prompt that carries that identity at runtime.
type Identity struct {
	// Role is the 人设 — the characterization the persona assumes.
	Role string `yaml:"role"`
	// SystemPrompt is the identity block injected as the system prompt.
	SystemPrompt string `yaml:"systemPrompt"`
}

// EmotionParams configures the persona's emotion state machine and its per-
// persona memory isolation namespace. Transitions may be empty, in which case
// the emotion package installs its default transition table.
type EmotionParams struct {
	InitialState emotion.EmotionState                            `yaml:"initialState"`
	DecayRate    float64                                         `yaml:"decayRate"`
	Transitions  map[emotion.EmotionState][]emotion.EmotionState `yaml:"transitions"`
	// MemoryNamespace is the memory isolation namespace for this persona.
	MemoryNamespace string `yaml:"memoryNamespace"`
}

// AffectionParams defines this persona's affection curve bounds and the default
// step applied to an Adjust call that carries no delta.
type AffectionParams struct {
	Initial int `yaml:"initial"`
	Min     int `yaml:"min"`
	Max     int `yaml:"max"`
	Delta   int `yaml:"delta"`
}

// Persona is a loaded persona definition. It describes who a character is (the
// identity, personality, speech style, catchphrase, background, values) and
// never restricts what that character can do.
type Persona struct {
	ID           string          `yaml:"id"`
	Name         string          `yaml:"name"`
	CharacterRef string          `yaml:"characterRef"`
	Identity     Identity        `yaml:"identity"`
	Personality  string          `yaml:"personality"`
	SpeechStyle  string          `yaml:"speechStyle"`
	Catchphrase  string          `yaml:"catchphrase"`
	Background   string          `yaml:"background"`
	Values       []string        `yaml:"values"`
	Emotion      EmotionParams   `yaml:"emotion"`
	Affection    AffectionParams `yaml:"affection"`
}

// EmotionConfig converts this persona's own fields into the params consumed by
// the emotion machine constructor.
func (p *Persona) EmotionConfig() emotion.Params {
	return emotion.Params{
		InitialState: p.Emotion.InitialState,
		DecayRate:    p.Emotion.DecayRate,
		Transitions:  p.Emotion.Transitions,
	}
}

// MemoryNamespace returns the effective memory isolation namespace for this
// persona — the configured one, or a derived default of "persona.<id>" when none
// is set. The derived default guarantees per-persona isolation.
func (p *Persona) MemoryNamespace() string {
	if p.Emotion.MemoryNamespace != "" {
		return p.Emotion.MemoryNamespace
	}
	return defaultMemoryNS + "." + p.ID
}

// NewMachine builds the persona's emotion state machine from its config.
func (p *Persona) NewMachine() (*emotion.Machine, error) {
	return emotion.NewMachine(p.EmotionConfig())
}

// NewAffection builds the persona's affection tracker from its curve config,
// applying default bounds when no curve was defined.
func (p *Persona) NewAffection() (*emotion.Affection, error) {
	params := p.Affection
	if params.Min == 0 && params.Max == 0 && params.Initial == 0 && params.Delta == 0 {
		params = AffectionParams{
			Initial: defaultAffectionInit,
			Min:     defaultAffectionMin,
			Max:     defaultAffectionMax,
			Delta:   defaultAffectionDelta,
		}
	}
	return emotion.NewAffection(params.Initial, params.Min, params.Max)
}