package domain

import (
	"errors"
	"git.cin.su/m/Assistant/contracts/work"
)

var ErrGovernedEvolution = errors.New("governed evolution gate failed")

func RunGovernedEvolution(needRef string, ops work.GovernedEvolutionOps) (work.GovernedEvolutionResult, error) {
	result := work.GovernedEvolutionResult{NeedRef: needRef, Stages: []work.EvolutionRunStage{work.EvolutionNeedRecorded}}
	if needRef == "" || ops.CreateCandidate == nil || ops.Evaluate == nil || ops.SandboxBuild == nil || ops.Benchmark == nil || ops.Promote == nil || ops.Rollback == nil || ops.LearningLedgerOutcome == nil {
		return result, ErrGovernedEvolution
	}
	candidate, err := ops.CreateCandidate()
	if err != nil {
		return result, err
	}
	if candidate.ID == "" || candidate.ProposalRef == "" {
		return result, ErrGovernedEvolution
	}
	result.CandidateRef = candidate.ID
	result.Stages = append(result.Stages, work.EvolutionCandidateBuilt)
	evaluation, err := ops.Evaluate(candidate)
	if err != nil || !evaluation.ValidFor(candidate) {
		return result, ErrGovernedEvolution
	}
	result.EvaluationRef = evaluation.CandidateRef
	result.Stages = append(result.Stages, work.EvolutionIndependentlyEvaluated)
	sandboxEvidence, err := ops.SandboxBuild(candidate)
	if err != nil || sandboxEvidence == "" {
		return result, ErrGovernedEvolution
	}
	candidate.SandboxEvidenceRefs = append(candidate.SandboxEvidenceRefs, sandboxEvidence)
	result.EvidenceRefs = append(result.EvidenceRefs, sandboxEvidence)
	result.Stages = append(result.Stages, work.EvolutionSandboxed)
	benchmarkEvidence, passed, err := ops.Benchmark(candidate)
	if err != nil || !passed || benchmarkEvidence == "" {
		result = rollbackEvolution(result, candidate, ops)
		return result, ErrGovernedEvolution
	}
	candidate.BenchmarkEvidenceRefs = append(candidate.BenchmarkEvidenceRefs, benchmarkEvidence)
	result.EvidenceRefs = append(result.EvidenceRefs, benchmarkEvidence)
	result.Stages = append(result.Stages, work.EvolutionBenchmarked)
	if ops.Canary != nil {
		canaryEvidence, passed, canaryErr := ops.Canary(candidate)
		if canaryErr != nil || !passed || canaryEvidence == "" {
			result = rollbackEvolution(result, candidate, ops)
			return result, ErrGovernedEvolution
		}
		result.EvidenceRefs = append(result.EvidenceRefs, canaryEvidence)
		result.Stages = append(result.Stages, work.EvolutionCanaried)
	}
	promotionRef, err := ops.Promote(candidate, evaluation)
	if err != nil || promotionRef == "" {
		result = rollbackEvolution(result, candidate, ops)
		return result, ErrGovernedEvolution
	}
	result.Promoted = true
	result.Stages = append(result.Stages, work.EvolutionPromoted)
	result.LearningLedgerOutcomeRef, err = ops.LearningLedgerOutcome(result)
	if err != nil || result.LearningLedgerOutcomeRef == "" {
		return result, ErrGovernedEvolution
	}
	return result, nil
}

func rollbackEvolution(result work.GovernedEvolutionResult, candidate work.EvolutionCandidate, ops work.GovernedEvolutionOps) work.GovernedEvolutionResult {
	ref, err := ops.Rollback(candidate)
	if err == nil && ref != "" {
		result.RollbackRef = ref
		result.Stages = append(result.Stages, work.EvolutionRolledBack)
		result.LearningLedgerOutcomeRef, _ = ops.LearningLedgerOutcome(result)
	}
	return result
}