package sourcerelatedness

import (
	"context"
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/validate/spells/spellpayload"
)

const Key = "extract/dnd/spells/source_relatedness"
const WarningReasonCode = "spell_not_near_source"

var _ contracts.Validator = (*Validator)(nil)

type Validator struct{}

func New() *Validator {
	return &Validator{}
}

func (v *Validator) Name() string {
	return Key
}

func (v *Validator) ExecutionClass() contracts.ExecutionClass {
	return contracts.ExecutionClassDeterministic
}

func (v *Validator) Validate(ctx context.Context, req contracts.ValidationRequest) (contracts.ValidationResult, error) {
	payload, err := spellpayload.ValidationRequestPayload(req)
	if err != nil {
		return contracts.ValidationResult{Approved: true}, nil
	}
	if err := spellpayload.ValidateShape(payload); err != nil {
		return contracts.ValidationResult{Approved: true}, nil
	}

	var warnings []contracts.Warning
	for spellIndex, spell := range payload.SpellCasts {
		if !spellAppearsInCitedText(req.Source, spell) {
			warnings = append(warnings, contracts.Warning{
				Scope:      fmt.Sprintf("spell_casts[%d]", spellIndex),
				ReasonCode: WarningReasonCode,
				Message:    fmt.Sprintf("spell %q was not found in cited source text", strings.TrimSpace(spell.Spell)),
			})
		}
	}
	return contracts.ValidationResult{Approved: true, Warnings: warnings}, nil
}

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

func Register(registry *pipeline.ValidatorRegistry) error {
	return registry.RegisterWithSpec(Spec(), func() (contracts.Validator, error) {
		return New(), nil
	})
}

func spellAppearsInCitedText(doc *source.SourceDocument, spell spellpayload.SpellCast) bool {
	name := strings.ToLower(strings.TrimSpace(spell.Spell))
	if name == "" {
		return true
	}
	for _, ref := range spellpayload.SourceRefCandidates(doc, spell) {
		text, ok := spellpayload.CitedText(doc, ref)
		if !ok {
			continue
		}
		if strings.Contains(strings.ToLower(text), name) {
			return true
		}
	}
	return false
}