package sourcerelatedness

import (
	"context"
	"fmt"

	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared/diagnostics"
	combatshape "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/combatturns/shape"
)

const (
	Key               = "extract/dnd/combat-turns/source_relatedness"
	WarningReasonCode = "combat_turn_not_near_source"
	policy            = "dnd.combat_turns.validator.source_relatedness.v2"
)

type Options struct{}
type Validator struct{}

var _ contracts.TypedValidator[dnd.CombatTurnList] = (*Validator)(nil)
var _ pipeline.CheckpointFingerprintProvider = (*Validator)(nil)

func New(Options) *Validator      { return &Validator{} }
func (v *Validator) Name() string { return Key }
func (v *Validator) ExecutionClass() contracts.ExecutionClass {
	return contracts.ExecutionClassDeterministic
}
func (v *Validator) CheckpointFingerprints() []pipeline.CheckpointFingerprint {
	return []pipeline.CheckpointFingerprint{{Name: "policy", Value: policy}}
}

func (v *Validator) Validate(_ context.Context, req contracts.TypedValidationRequest[dnd.CombatTurnList]) (contracts.ValidationResult, error) {
	if combatshape.Validate(req.Value) != nil {
		return contracts.ValidationResult{Approved: true}, nil
	}

	citedTexts := make([]string, len(req.Value.CombatTurns))
	for turnIndex, turn := range req.Value.CombatTurns {
		citedText, err := shared.CitedText(req.Source, turn.SourceRefs)
		if err != nil {
			return contracts.ValidationResult{Approved: true}, nil
		}
		citedTexts[turnIndex] = citedText
	}
	warnings := make([]contracts.Warning, 0)
	for turnIndex, turn := range req.Value.CombatTurns {
		citedText := citedTexts[turnIndex]
		if actorAppearsInCitedText(citedText, turn.Actor) {
			continue
		}
		warnings = append(warnings, contracts.Warning{
			Scope:      fmt.Sprintf("combat_turns[%d]", turnIndex),
			ReasonCode: WarningReasonCode,
			Message: diagnostics.Aggregate("combat turn not near source", []string{
				fmt.Sprintf("actor %s was not found in cited source text", diagnostics.Quote(turn.Actor)),
			}),
		})
	}
	return contracts.ValidationResult{Approved: true, Warnings: warnings}, nil
}
func actorAppearsInCitedText(citedText string, actor string) bool {
	return shared.ContainsTokenSequence(citedText, actor)
}

func Spec() pipeline.ValidatorSpec {
	return pipeline.ValidatorSpec{Key: Key, ExecutionClass: contracts.ExecutionClassDeterministic}
}

func Register(registry *pipeline.ValidatorRegistry) error {
	return pipeline.RegisterTypedValidatorBuilder(registry, dnd.CombatTurnListKind, Spec(), validateOptions, func(request pipeline.BuildRequest) (contracts.TypedValidator[dnd.CombatTurnList], error) {
		options, err := DecodeOptions(request.Options)
		if err != nil {
			return nil, err
		}
		return New(options), nil
	})
}

func DecodeOptions(options map[string]any) (Options, error) {
	if err := pipeline.RejectUnknownOptions(options); err != nil {
		return Options{}, err
	}
	return Options{}, nil
}

func validateOptions(options map[string]any) error { _, err := DecodeOptions(options); return err }