// Command labelgen labels utterances with the stage 0 grammars and prints JSONL.
//
// docs/plans/18-routing-heads-on-e5-small.md calls the labeled set the whole
// project, and it names the stage 0 grammars as the high-precision label
// functions to start from. This runs them — the real ones, in the real
// buildRouter order — rather than a reimplementation, so a rule change moves
// the training data with it.
//
// A grammar that declines leaves the line unlabeled. Those go to the model, and
// keeping them is the point: a set labeled only by the rules teaches only the
// rules.
//
//	go run ./cmd/labelgen < utterances.txt > labeled.jsonl
//
// The wakeword-act grammar is absent, because its allowlist is the deployment's
// enabled tool names and this tool has no deployment. Every other rule is here.
package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"os"
	"strings"

	"github.com/kami/maven/internal/router"
)

// label is one output row. The grammar name rides along so a reviewer can see
// which rule made the claim, and so a rule that turns out to be wrong can have
// its rows pulled without re-running everything.
type label struct {
	Utterance string `json:"utterance"`
	Intent    string `json:"intent,omitempty"`
	Grammar   string `json:"grammar,omitempty"`
	Key       string `json:"key,omitempty"`
	Value     string `json:"value,omitempty"`
	Fn        string `json:"fn,omitempty"`
	Text      string `json:"text,omitempty"`
	Labeled   bool   `json:"labeled"`
}

// grammars is the daemon's canonical ordered stage-zero set. Label generation
// must not maintain a second copy: that drift was the defect fixed by V-693.
func grammars() []router.Grammar {
	return router.StageZeroGrammars(router.DefaultActMatcher{})
}

func match(gs []router.Grammar, utterance string) label {
	out := label{Utterance: utterance}
	for _, g := range gs {
		d, matched, ok := g.Evaluate(utterance)
		if !matched || !ok {
			continue
		}
		out.Intent = string(d.Intent)
		out.Grammar = g.Name
		out.Key = d.Slots.Key
		out.Value = d.Slots.Value
		out.Fn = d.Slots.Fn
		out.Text = d.Slots.Text
		out.Labeled = true
		return out
	}
	return out
}

func main() {
	gs := grammars()
	in := bufio.NewScanner(os.Stdin)
	in.Buffer(make([]byte, 0, 64*1024), 1024*1024)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	enc := json.NewEncoder(out)
	var seen, labeled int
	for in.Scan() {
		line := strings.TrimSpace(in.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		seen++
		l := match(gs, line)
		if l.Labeled {
			labeled++
		}
		if err := enc.Encode(l); err != nil {
			fmt.Fprintln(os.Stderr, "labelgen:", err)
			os.Exit(1)
		}
	}
	if err := in.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "labelgen:", err)
		os.Exit(1)
	}
	// Coverage on stderr, so the count is visible without polluting the JSONL.
	fmt.Fprintf(os.Stderr, "labelgen: %d/%d labeled by %d grammars\n", labeled, seen, len(gs))
}