package main

import (
	"bufio"
	"context"
	"log"
	"os"
	"path/filepath"
	"sort"
	"strings"

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

// Seed loading replicated from cmd/mavend/voicewire.go (seedClassifier) and
// internal/router/semantic/helpers_test.go, which build the same classifier
// from models/seeds/<intent>.txt. The daemon and the eval fixture must agree
// on the seeds; so must a measurement.
const seedDir = "models/seeds"

var seedIntents = []router.Intent{
	router.IntentAct, router.IntentReminder, router.IntentFact,
	router.IntentNote, router.IntentQuery, router.IntentChat, router.IntentSystem,
}

// buildMinimalRouter reproduces internal/router/semantic/buildMinimalRouter:
// the daemon's grammar set, a hash-embedder classifier seeded from
// models/seeds, and the deployed 0.55 threshold. Deterministic and
// reproducible. The ONNX embedder and the routing heads score elsewhere;
// this is the floor the eval fixture reports as the legacy baseline.
func buildMinimalRouter() *router.Router {
	acts := router.DefaultActMatcher{Fns: semantic.ExperimentActVerbs()}
	cls := router.NewClassifier(router.NewHashEmbedder(1024))
	seedClassifier(cls)
	return router.New(router.Config{
		Grammars:   router.StageZeroGrammars(acts),
		Classifier: cls,
		Extractor: router.Extractor{
			Time:  router.StubDateTimeParser{},
			Acts:  acts,
			Facts: router.DefaultFactParser{},
		},
		Threshold: 0.55,
	})
}

func seedClassifier(c *router.Classifier) {
	// Walk up to find models/seeds like the daemon's seedPath, so the program
	// can run from any depth of the repo tree.
	dir := seedDir
	for i := 0; i < 5; i++ {
		if st, err := os.Stat(dir); err == nil && st.IsDir() {
			break
		}
		dir = filepath.Join("..", dir)
	}
	ctx := context.Background()
	total := 0
	for _, intent := range seedIntents {
		path := filepath.Join(dir, string(intent)+".txt")
		f, err := os.Open(path)
		if err != nil {
			log.Printf("legacy: open seed %s: %v", path, err)
			continue
		}
		sc := bufio.NewScanner(f)
		lines := []string{}
		for sc.Scan() {
			line := strings.TrimSpace(sc.Text())
			if line == "" || strings.HasPrefix(line, "#") {
				continue
			}
			lines = append(lines, line)
		}
		f.Close()
		sort.Strings(lines)
		for _, line := range lines {
			if err := c.AddExample(ctx, intent, line); err != nil {
				log.Printf("legacy: seed %s %q: %v", intent, line, err)
				continue
			}
			total++
		}
	}
	log.Printf("legacy: loaded %d seed examples from %s", total, dir)
}