// Package replay ports scripts/distillation/replay.ts to Go.
//
// Replay takes a task → retrieves matching playbooks/RAG records →
// builds a context bundle → calls a LOCAL model via the gateway's
// /v1/chat → validates → escalates to a stronger model if needed →
// logs the run as new evidence in `data/_kb/replay_runs.jsonl`.
//
// Spec invariants (carry over from replay.ts):
//   - never bypass retrieval (unless caller passes NoRetrieval)
//   - never discard provenance
//   - never allow free-form hallucinated output (validation gate)
//   - log every run as new evidence
//
// This is NOT training — it's runtime behavior shaping via retrieval.
package replay

// ReplayRequest mirrors the TS interface. NoRetrieval skips the
// context bundle entirely (baseline mode for A/B tests). DryRun returns
// a deterministic synthetic response without calling the gateway —
// used by tests to exercise retrieval/validation without an LLM.
type ReplayRequest struct {
	Task             string
	LocalOnly        bool
	AllowEscalation  bool
	NoRetrieval      bool
	DryRun           bool
	GatewayURL       string // overrides $LH_GATEWAY_URL
	LocalModel       string // overrides default
	EscalationModel  string // overrides default
}

// RagSample is one record in exports/rag/playbooks.jsonl.
type RagSample struct {
	ID             string   `json:"id"`
	Title          string   `json:"title"`
	Content        string   `json:"content"`
	Tags           []string `json:"tags"`
	SourceRunID    string   `json:"source_run_id"`
	SuccessScore   string   `json:"success_score"`
	SourceCategory string   `json:"source_category"`
}

// RetrievedArtifact is one playbook surfaced into a ContextBundle.
type RetrievedArtifact struct {
	RagID          string   `json:"rag_id"`
	SourceRunID    string   `json:"source_run_id"`
	Title          string   `json:"title"`
	ContentPreview string   `json:"content_preview"` // first 240 chars
	SuccessScore   string   `json:"success_score"`
	Tags           []string `json:"tags"`
	Score          float64  `json:"score"`
}

// ContextBundle is what the prompt builder consumes. Empty bundles
// (no retrieved playbooks) still pass through — buildPrompt downgrades
// to a no-context prompt when both accepted and warnings are empty.
type ContextBundle struct {
	RetrievedPlaybooks    []RetrievedArtifact `json:"retrieved_playbooks"`
	PriorSuccessfulOutputs []RetrievedArtifact `json:"prior_successful_outputs"`
	FailurePatterns       []RetrievedArtifact `json:"failure_patterns"`
	ValidationSteps       []string            `json:"validation_steps"`
	BundleTokenEstimate   int                 `json:"bundle_token_estimate"`
}

// ValidationResult is the deterministic gate's verdict. Reasons is
// always non-nil so JSON consumers can iterate without a nil check.
type ValidationResult struct {
	Passed  bool     `json:"passed"`
	Reasons []string `json:"reasons"`
}

// ReplayResult is what Replay returns. Mirrors the TS type one-to-one
// so JSONL emitted by either runtime parses identically.
type ReplayResult struct {
	InputTask           string         `json:"input_task"`
	TaskHash            string         `json:"task_hash"`
	RetrievedArtifacts  RetrievedIDs   `json:"retrieved_artifacts"`
	ContextBundle       *ContextBundle `json:"context_bundle"`
	ModelResponse       string         `json:"model_response"`
	ModelUsed           string         `json:"model_used"`
	EscalationPath      []string       `json:"escalation_path"`
	ValidationResult    ValidationResult `json:"validation_result"`
	RecordedRunID       string         `json:"recorded_run_id"`
	RecordedAt          string         `json:"recorded_at"`
	DurationMs          int64          `json:"duration_ms"`
}

// RetrievedIDs is the {rag_ids} envelope the TS shape uses.
type RetrievedIDs struct {
	RagIDs []string `json:"rag_ids"`
}

// Defaults match replay.ts. Override via env or ReplayRequest fields.
const (
	DefaultLocalModel       = "qwen3.5:latest"
	DefaultEscalationModel  = "deepseek-v3.1:671b"
	DefaultGatewayURL       = "http://localhost:3110"
)