package contracts

import (
	"context"
	"fmt"

	"gitea.maximumdirect.net/eric/audita/v3/internal/core/chunking"
	"gitea.maximumdirect.net/eric/audita/v3/internal/core/config"
	"gitea.maximumdirect.net/eric/audita/v3/internal/core/glossary"
	"gitea.maximumdirect.net/eric/audita/v3/internal/core/modulecatalog"
	"gitea.maximumdirect.net/eric/audita/v3/internal/core/schema"
	"gitea.maximumdirect.net/eric/audita/v3/internal/framework/outcomes"
	"gitea.maximumdirect.net/eric/audita/v3/internal/framework/promptcontext"
	"gitea.maximumdirect.net/eric/audita/v3/internal/framework/proposals"
	"gitea.maximumdirect.net/eric/audita/v3/internal/framework/structuredoutput"
	"gitea.maximumdirect.net/eric/audita/v3/internal/framework/validators"
)

type StructuredLLMClient = structuredoutput.Client

// TranscriptModule is the minimal contract for framework-integrated modules.
type TranscriptModule interface {
	Key() string
	ReplacementPolicy() proposals.ReplacementPolicy
	Validators() []Validator
	Propose(ctx context.Context, req ProposalRequest) (ProposalResult, error)
}

// Validator evaluates candidate proposals and returns one decision per proposal index.
type Validator interface {
	Name() string
	Validate(ctx context.Context, req ValidationRequest) (validators.Result, error)
}

type StructuredCompletionRequest = structuredoutput.Request
type StructuredCompletionResponse = structuredoutput.Response

// ModuleRunSpec identifies one resolved module instance in a pipeline.
type ModuleRunSpec struct {
	ModuleKey         string                      `json:"module_key"`
	InstanceName      string                      `json:"instance_name"`
	ReplacementPolicy proposals.ReplacementPolicy `json:"replacement_policy"`
	Index             int                         `json:"-"`
	ID                *string                     `json:"-"`
	Settings          config.Stage                `json:"-"`
	Glossary          []glossary.Entry            `json:"-"`
	ProtectedTerms    []glossary.Term             `json:"-"`
	ProposalClient    StructuredLLMClient         `json:"-"`
	ValidationClient  StructuredLLMClient         `json:"-"`
}

// SectionMetadata captures chunk-level metadata without embedding full segment payloads.
type SectionMetadata struct {
	Index           int `json:"section_index"`
	StartSegmentID  int `json:"start_segment_id"`
	EndSegmentID    int `json:"end_segment_id"`
	EstimatedTokens int `json:"estimated_tokens"`
	SegmentCount    int `json:"segment_count"`
}

// SectionMetadataFromSection converts a chunking section into framework metadata.
func SectionMetadataFromSection(section chunking.Section) SectionMetadata {
	return SectionMetadata{
		Index:           section.Index,
		StartSegmentID:  section.StartSegmentID,
		EndSegmentID:    section.EndSegmentID,
		EstimatedTokens: section.EstimatedTokens,
		SegmentCount:    len(section.Segments),
	}
}

// ExecutionContext carries shared execution state for proposal generation and validation.
type ExecutionContext struct {
	StageIndex *int    `json:"stage_index,omitempty"`
	StageID    *string `json:"stage_id,omitempty"`
	// ReportDiagnosticError may be called concurrently; it must not affect processing.
	ReportDiagnosticError func(error)                      `json:"-"`
	Settings              config.Stage                     `json:"-"`
	WorkingTranscript     *schema.Transcript               `json:"-"`
	Glossary              []glossary.Entry                 `json:"-"`
	ProtectedTerms        []glossary.Term                  `json:"-"`
	GlossaryVariables     *promptcontext.GlossaryVariables `json:"-"`
	Section               *SectionMetadata                 `json:"section,omitempty"`
	DiagnosticsDir        string                           `json:"diagnostics_dir,omitempty"`
}

// ProposalRequest is the input to module proposal generation.
type ProposalRequest struct {
	ExecutionContext
	RunSpec   ModuleRunSpec       `json:"run_spec"`
	LLMClient StructuredLLMClient `json:"-"`
}

type ProposalResult struct {
	Proposals  []proposals.CorrectionProposal `json:"proposals,omitempty"`
	Operations []outcomes.Operation           `json:"operations,omitempty"`
}

// ValidationRequest is the input to validator execution.
type ValidationRequest = validators.Request

// ResolveModuleRunSpecs derives isolated consumer views from resolved settings.
func ResolveModuleRunSpecs(cfg *config.Config) []ModuleRunSpec {
	if cfg == nil {
		return nil
	}
	specs := make([]ModuleRunSpec, len(cfg.Pipeline.Stages))
	for i, item := range cfg.Pipeline.Stages {
		selected := glossary.Select(cfg.GlossaryCollections, item.Glossaries)
		protected := glossary.Select(cfg.GlossaryCollections, item.ProtectedTerms)
		var excluded []glossary.Entry
		if item.Module == modulecatalog.KeyGlossary {
			excluded = selected
		}
		specs[i] = ModuleRunSpec{ModuleKey: item.Module, InstanceName: fmt.Sprintf("%s_%d", item.Module, i+1), Index: i, ID: item.ID, Settings: item, Glossary: selected, ProtectedTerms: glossary.Vocabulary(protected, excluded)}
	}
	return specs
}