package workflow

// modes.go — adapters that wrap §3.4 capabilities + §3.5 drift +
// distillation scorer as workflow.Mode functions. Each mode follows
// the same glue pattern: marshal the generic input map through a
// typed struct (so workflow YAML schemas are self-documenting and
// validation errors are clear), call the underlying capability,
// return a generic output map.
//
// Pure modes (no I/O): MatrixRelevance, MatrixDowngrade,
// DistillationScore, DriftScorer.
//
// HTTP modes: MatrixSearch + PlaybookRecord — observerd talks to
// matrixd over HTTP since the search/record paths need vectord
// access. Constructed via factory funcs that take the matrixd base
// URL + an http.Client.

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"

	"git.agentview.dev/profit/golangLAKEHOUSE/internal/distillation"
	"git.agentview.dev/profit/golangLAKEHOUSE/internal/drift"
	"git.agentview.dev/profit/golangLAKEHOUSE/internal/matrix"
)

// ─── Pure-function wrappers ─────────────────────────────────────

// MatrixRelevance wraps matrix.FilterChunks. Input shape:
//
//	{
//	  "focus":     {"Path":"...", "Content":"...", ...},
//	  "chunks":    [{"source":"...", "doc_id":"...", "text":"...", "score":0.8}, ...],
//	  "threshold": 0.3   # optional; default = matrix.DefaultRelevanceThreshold
//	}
//
// Output: {"kept":[...], "dropped":[...], "threshold":N, "total_in":N}.
func MatrixRelevance(_ Context, input map[string]any) (map[string]any, error) {
	var req struct {
		Focus     matrix.FocusFile        `json:"focus"`
		Chunks    []matrix.CandidateChunk `json:"chunks"`
		Threshold float64                 `json:"threshold"`
	}
	if err := remarshalInput(input, &req); err != nil {
		return nil, fmt.Errorf("matrix.relevance: %w", err)
	}
	threshold := req.Threshold
	if threshold == 0 {
		threshold = matrix.DefaultRelevanceThreshold
	}
	res := matrix.FilterChunks(req.Focus, req.Chunks, threshold)
	return map[string]any{
		"kept":      res.Kept,
		"dropped":   res.Dropped,
		"threshold": res.Threshold,
		"total_in":  res.TotalIn,
	}, nil
}

// MatrixDowngrade wraps matrix.MaybeDowngrade. Input shape:
//
//	{
//	  "mode":  "codereview_lakehouse",
//	  "model": "x-ai/grok-4.1-fast",
//	  "forced_mode":          false,         # optional
//	  "force_full_override":  false          # optional
//	}
//
// Output: matrix.DowngradeDecision JSON.
func MatrixDowngrade(_ Context, input map[string]any) (map[string]any, error) {
	var req struct {
		Mode              string `json:"mode"`
		Model             string `json:"model"`
		ForcedMode        bool   `json:"forced_mode"`
		ForceFullOverride bool   `json:"force_full_override"`
	}
	if err := remarshalInput(input, &req); err != nil {
		return nil, fmt.Errorf("matrix.downgrade: %w", err)
	}
	if req.Mode == "" || req.Model == "" {
		return nil, fmt.Errorf("matrix.downgrade: mode and model are required")
	}
	dec := matrix.MaybeDowngrade(matrix.DowngradeInput{
		Mode:              req.Mode,
		Model:             req.Model,
		ForcedMode:        req.ForcedMode,
		ForceFullOverride: req.ForceFullOverride,
	})
	return map[string]any{
		"mode":            dec.Mode,
		"downgraded_from": dec.DowngradedFrom,
		"reason":          dec.Reason,
	}, nil
}

// MatrixDowngradeWithWeakList is the config-driven variant of
// MatrixDowngrade — callers pass cfg.Models.WeakModels at startup
// and the closure includes that list in every DowngradeInput.
// nil/empty list falls back to matrix.DefaultWeakModels (matching the
// plain MatrixDowngrade behavior).
func MatrixDowngradeWithWeakList(weakModels []string) Mode {
	return func(_ Context, input map[string]any) (map[string]any, error) {
		var req struct {
			Mode              string `json:"mode"`
			Model             string `json:"model"`
			ForcedMode        bool   `json:"forced_mode"`
			ForceFullOverride bool   `json:"force_full_override"`
		}
		if err := remarshalInput(input, &req); err != nil {
			return nil, fmt.Errorf("matrix.downgrade: %w", err)
		}
		if req.Mode == "" || req.Model == "" {
			return nil, fmt.Errorf("matrix.downgrade: mode and model are required")
		}
		dec := matrix.MaybeDowngrade(matrix.DowngradeInput{
			Mode:              req.Mode,
			Model:             req.Model,
			ForcedMode:        req.ForcedMode,
			ForceFullOverride: req.ForceFullOverride,
			WeakModels:        weakModels,
		})
		return map[string]any{
			"mode":            dec.Mode,
			"downgraded_from": dec.DowngradedFrom,
			"reason":          dec.Reason,
		}, nil
	}
}

// DistillationScore wraps distillation.ScoreRecord — re-runs the
// scorer over a single EvidenceRecord. Useful as a workflow node
// that grades a freshly-produced evidence row.
//
// Input: a JSON EvidenceRecord under the key "record":
//
//	{"record": {"run_id":"...", "task_id":"...", ...}}
//
// Output: ScoreOutput-ish map with category, reasons, sub_scores.
func DistillationScore(_ Context, input map[string]any) (map[string]any, error) {
	var req struct {
		Record distillation.EvidenceRecord `json:"record"`
	}
	if err := remarshalInput(input, &req); err != nil {
		return nil, fmt.Errorf("distillation.score: %w", err)
	}
	if req.Record.RunID == "" {
		return nil, fmt.Errorf("distillation.score: record.run_id required")
	}
	out := distillation.ScoreRecord(req.Record)
	return map[string]any{
		"category":   string(out.Category),
		"reasons":    out.Reasons,
		"sub_scores": out.SubScores,
	}, nil
}

// DriftScorer wraps drift.ComputeScorerDrift. Input shape:
//
//	{
//	  "inputs": [
//	    {"record": {...EvidenceRecord...}, "persisted_category": "accepted"},
//	    ...
//	  ],
//	  "include_entries": false  # optional, default false
//	}
//
// Output: ScorerDriftReport JSON.
func DriftScorer(_ Context, input map[string]any) (map[string]any, error) {
	var req struct {
		Inputs []drift.ScorerDriftInput `json:"inputs"`
		IncludeEntries bool              `json:"include_entries"`
	}
	if err := remarshalInput(input, &req); err != nil {
		return nil, fmt.Errorf("drift.scorer: %w", err)
	}
	if len(req.Inputs) == 0 {
		return nil, fmt.Errorf("drift.scorer: inputs must be non-empty")
	}
	report := drift.ComputeScorerDrift(req.Inputs, req.IncludeEntries)
	bs, err := json.Marshal(report)
	if err != nil {
		return nil, err
	}
	var asMap map[string]any
	if err := json.Unmarshal(bs, &asMap); err != nil {
		return nil, err
	}
	return asMap, nil
}

// ─── HTTP-backed modes ──────────────────────────────────────────

// MatrixSearch returns a workflow.Mode bound to a matrixd base URL
// and HTTP client. The mode posts to /v1/matrix/search via the
// gateway-internal upstream (caller passes the URL).
//
// Input shape mirrors matrix.SearchRequest (see retrieve.go).
// Output is the matrix.SearchResponse JSON.
func MatrixSearch(matrixdURL string, hc *http.Client) Mode {
	return func(ctx Context, input map[string]any) (map[string]any, error) {
		bs, err := json.Marshal(input)
		if err != nil {
			return nil, fmt.Errorf("matrix.search: marshal: %w", err)
		}
		req, err := http.NewRequestWithContext(ctx.Ctx, http.MethodPost,
			matrixdURL+"/matrix/search", bytes.NewReader(bs))
		if err != nil {
			return nil, err
		}
		req.Header.Set("Content-Type", "application/json")
		resp, err := hc.Do(req)
		if err != nil {
			return nil, fmt.Errorf("matrix.search: %w", err)
		}
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			body, _ := io.ReadAll(resp.Body)
			return nil, fmt.Errorf("matrix.search: status %d: %s", resp.StatusCode, body)
		}
		var out map[string]any
		if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
			return nil, fmt.Errorf("matrix.search: decode: %w", err)
		}
		return out, nil
	}
}

// ─── Helpers ─────────────────────────────────────────────────────

// remarshalInput round-trips a generic input map through JSON into
// the typed target struct. Same trick as the matrixd handlers — gives
// us schema validation for free without writing custom field-by-field
// coercion.
func remarshalInput(input map[string]any, target any) error {
	bs, err := json.Marshal(input)
	if err != nil {
		return err
	}
	return json.Unmarshal(bs, target)
}