package proposals

import (
	"fmt"
	"strings"
)

// CorrectionProposal is the base proposal emitted by correction modules.
type CorrectionProposal struct {
	TargetSegmentID int     `json:"id"`
	OriginalText    string  `json:"original_text"`
	CorrectedText   string  `json:"corrected_text"`
	Confidence      float64 `json:"confidence"`
}

// ProposalMetadata is framework-enriched execution metadata for a proposal.
type ProposalMetadata struct {
	ProposalIndex  int    `json:"proposal_index"`
	ModuleKey      string `json:"module_key"`
	ModuleInstance string `json:"module_instance"`
	SectionIndex   *int   `json:"section_index,omitempty"`
}

// EnrichedCorrectionProposal combines module-emitted proposal data with
// framework execution metadata.
type EnrichedCorrectionProposal struct {
	CorrectionProposal
	ProposalMetadata
}

// Validate checks only basic structural integrity of the proposal.
// Semantic checks (staleness, span presence, replacement behavior) are handled
// by proposal preview/application and validator execution.
func (p CorrectionProposal) Validate() error {
	if p.TargetSegmentID <= 0 {
		return fmt.Errorf("proposal id must be positive")
	}
	if strings.TrimSpace(p.OriginalText) == "" {
		return fmt.Errorf("proposal original_text must not be empty")
	}
	if p.Confidence < 0.0 || p.Confidence > 1.0 {
		return fmt.Errorf("proposal confidence must be between 0.0 and 1.0")
	}

	return nil
}