package main

import (
	"bufio"
	"context"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/kami/maven/internal/config"
	"github.com/kami/maven/internal/delivery"
	"github.com/kami/maven/internal/delivery/voicesink"
	"github.com/kami/maven/internal/dialogue"
	"github.com/kami/maven/internal/ipc"
	"github.com/kami/maven/internal/llm"
	"github.com/kami/maven/internal/memory"
	"github.com/kami/maven/internal/phraser"
	"github.com/kami/maven/internal/router"
	"github.com/kami/maven/internal/store"
	"github.com/kami/maven/internal/stt"
	"github.com/kami/maven/internal/tool"
	"github.com/kami/maven/internal/tts"
	"github.com/kami/maven/internal/voice"
	"github.com/kami/maven/internal/weather"
	"github.com/kami/maven/internal/worker"
)

// voiceWiring — everything the daemon needs to run the audio path. Held by
// cmd/mavend/main.go alongside the other wirings; closed on shutdown.
type voiceWiring struct {
	server    *voice.Server
	sessions  *voice.Sessions
	voiceSink delivery.Sink
	embedder  router.Embedder
	handler   *reactiveHandler // the reactive handler for IPC Chat
	// worker clients (set when configured as Remote): closed on shutdown so
	// mavsttd / mavttsd don't keep a stale conn into a restarting daemon.
	sttClient *worker.Client
	ttsClient *worker.Client
	// transcriber — the STT in use, exposed so the meeting recorder
	// (cmd/mavend/capture.go) can reuse it. Maven has exactly one STT and does
	// not grow a second one for capture: this is the same whisper.cpp worker the
	// voice path talks to.
	transcriber stt.Transcriber
	// mcp — the MCP client, nil unless the `mcp` block configures an enabled
	// server (Vikunja #251). Its tools land in the same allowlist as every
	// other act, so nothing else here has to know about it.
	mcp *mcpWiring
	// home — the Home Assistant client, nil unless the `smarthome` block is
	// enabled (Vikunja #256). Its devices land in the same allowlist as every
	// other act, so nothing else here has to know about it.
	home *homeWiring
	// netscan — the LAN scanner, nil unless the `netscan` block is enabled
	// (Vikunja #257).
	netscan *netWiring
}

// close releases the listener + worker conns. Safe to call on nil (when
// voice is not wired — wireVoice returns nil,nil).
func (w *voiceWiring) close() {
	if w == nil {
		return
	}
	if w.embedder != nil {
		_ = w.embedder.Close()
	}
	if w.server != nil {
		_ = w.server.Close()
	}
	if w.sttClient != nil {
		_ = w.sttClient.Close()
	}
	if w.ttsClient != nil {
		_ = w.ttsClient.Close()
	}
	w.mcp.close()
}

// wireVoice builds the audio path from cfg + a CoreAPI + a router. Returns
// nil wiring + nil error when voice isn't enabled (the caller's voice sink
// stays nil; the dispatcher's ChannelVoice routing drops silently).
//
// When voice is enabled, MUST wire a voicesink into the dispatcher's Voice
// slot using w.sessions (the caller does that — see main.go).
func wireVoice(cfg *config.Config, coreAPI ipc.CoreAPI, phr phraser.Phraser, memStore memory.Store, dataStore *store.Store, eco *ecosystemWiring) (*voiceWiring, error) {
	if cfg.Voice == nil || !cfg.Voice.Enabled {
		return nil, nil
	}
	w := &voiceWiring{}

	// ----- stt (Stub in-process OR Remote via worker socket) -----
	var transcriber stt.Transcriber
	if cfg.Voice.Stt != nil && cfg.Voice.Stt.Socket != "" {
		c := worker.Dial(cfg.Voice.Stt.Socket)
		w.sttClient = c
		lang := cfg.Voice.Stt.Lang
		if lang == "" {
			lang = cfg.Voice.Lang
		}
		transcriber = stt.NewRemote(c, lang)
	} else {
		transcriber = stt.NewStub()
	}
	w.transcriber = transcriber

	// ----- tts (Stub in-process OR Remote) -----
	var synthesizer tts.Synthesizer
	if cfg.Voice.Tts != nil && cfg.Voice.Tts.Socket != "" {
		c := worker.Dial(cfg.Voice.Tts.Socket)
		w.ttsClient = c
		lang := cfg.Voice.Tts.Lang
		if lang == "" {
			lang = cfg.Voice.Lang
		}
		synthesizer = tts.NewRemote(c, lang, cfg.Voice.Tts.Voice)
	} else {
		synthesizer = tts.NewStub()
	}

	// ----- router: embedder (ONNX when configured, floor HashEmbedder otherwise) -----
	var emb router.Embedder
	if cfg.Voice.Embedder != nil {
		onnx, err := router.NewONNXEmbedder(
			cfg.Voice.Embedder.ModelPath,
			cfg.Voice.Embedder.TokenizerPath,
			cfg.Voice.Embedder.LibPath,
		)
		if err != nil {
			w.close()
			return nil, fmt.Errorf("embedder: %w", err)
		}
		log.Printf("voice: onnx embedder loaded (%d dim)", onnx.Dim())
		emb = onnx
	} else {
		log.Printf("voice: embedder not configured, using HashEmbedder floor")
		emb = router.NewHashEmbedder(1024)
	}
	w.embedder = emb
	checkStoredEmbedder(dataStore, emb)

	// ----- tool executor (the enabled act allowlist, store-backed) -----
	// Config tools are the declarative bootstrap: seed them into the store as
	// enabled (editing mavend.json IS the human enable act). Ad-hoc tools are
	// enabled later through the authed mavweb surface. The executor + matcher
	// both read the store live, so a newly-enabled tool is runnable without a
	// daemon restart.
	seedTools(coreAPI, cfg.Voice.Tools)
	exec := tool.NewExecutor(coreAPI, time.Duration(cfg.Voice.ToolTimeout))
	// MCP servers (Vikunja #251): discovery PROPOSES tools into the same
	// allowlist, so an MCP tool is enabled by hand on /tools like any other and
	// runs through the same confirm turn. Off unless the `mcp` block configures
	// an enabled server.
	w.mcp = wireMCP(cfg, dataStore)
	if w.mcp != nil {
		exec = exec.WithMCP(w.mcp.caller())
	}
	// The house (Vikunja #256): same story as MCP. Discovery PROPOSES a row per
	// controllable device, always destructive, and Kami enables the ones he
	// wants on /tools. Off unless the `smarthome` block is enabled.
	w.home = wireSmartHome(cfg, dataStore)
	if w.home != nil {
		exec = exec.WithHome(w.home.caller())
	}
	// The LAN scanner (Vikunja #257): a read, bounded to the configured
	// subnets and rate-limited. Off unless the `netscan` block is enabled.
	w.netscan = wireNetScan(cfg)
	matcher := tool.NewMatcher(coreAPI)

	// ----- weather provider (Open-Meteo when configured, Stub otherwise) -----
	var weatherProvider weather.Provider
	var weatherLocation string
	if cfg.Voice.Weather != nil && cfg.Voice.Weather.Provider == "open-meteo" {
		weatherProvider = weather.NewOpenMeteoProvider()
		weatherLocation = cfg.Voice.Weather.DefaultLocation
		log.Printf("voice: weather provider: open-meteo (default location: %s)", cfg.Voice.Weather.DefaultLocation)
	} else {
		weatherProvider = weather.NewStubProvider()
		log.Printf("voice: weather provider: stub (not configured)")
	}

	// The replier uses the same llama-server as the phraser.
	var llmClient *llm.Client
	if lp, ok := phr.(*phraser.LLMPhraser); ok {
		// llmClientFor, not llm.New: this client must follow the phraser onto
		// the new llama-server when the resident model is swapped (Vikunja #250).
		llmClient = llmClientFor(lp, 60*time.Second)
	}
	// ----- router (the cascade; floor examples seed the classifier) -----
	// The act matcher's allowlist is exactly the enabled tool names — the
	// router only matches acts the executor can run (one source of truth).
	threshold := cfg.Voice.RouterThreshold
	if threshold <= 0 {
		threshold = config.DefaultRouterThreshold
	}
	// The resident model routes by default: 63.2% of held-out intents right
	// against the classifier's 50.0%, at about 1s a turn instead of 30ms (see
	// config.VoiceConfig.LLMRouter). The classifier always stays wired as the
	// fallback, so a model error never breaks a turn.
	rtr := buildRouter(emb, matcher, threshold, pickLLMRouter(cfg.Voice.UseLLMRouter(), llmClient))

	// ----- sessions registry (shared with voicesink) -----
	sessions := voice.NewSessions()
	w.sessions = sessions

	// ----- voice sink (proactive nudges: dispatcher → voicesink → tts → push to client) -----
	w.voiceSink = voicesink.New(synthesizer, sessions)

	// ----- memory (long-term vector storage) -----
	// Persistent (store-backed, survives restarts) when the daemon passes one;
	// falls back to the in-memory floor otherwise (tests / no-store paths).
	if memStore == nil {
		memStore = memory.NewInMemoryStore()
	}

	// ----- dialogue (multi-turn slot carry-over; 2-min follow-up window) -----
	// Store-backed when the daemon passes a store, so a restart mid-conversation
	// keeps the thread (Vikunja #363). Sessions past their TTL are dropped on
	// load, never revived. Clarify's parked question stays in memory only.
	var dialogueSessions *dialogue.SessionStore
	if dataStore != nil {
		dialogueSessions = dialogue.NewPersistentSessionStore(2*time.Minute, dataStore)
		if err := dialogueSessions.Load(context.Background(), time.Now()); err != nil {
			log.Printf("dialogue: load saved sessions: %v", err)
		}
	} else {
		dialogueSessions = dialogue.NewSessionStore(2 * time.Minute)
	}
	clarifyStore := dialogue.NewClarifyStore(clarifyTTL)
	timeParser := router.NewPythonDateParser()

	// ----- replier (LLM-backed when the engine is on, Stub floor otherwise) -----
	replier := voice.Replier(voice.NewStubReplier())
	if llmClient != nil {
		replier = newLLMReplier(llmClient, contextBlockFn(cfg, time.Now))
	}

	// ----- the handler (the reactive path; closes over stt / tts / router / coreAPI / memory) -----
	h := &reactiveHandler{
		stt:      transcriber,
		tts:      synthesizer,
		router:   rtr,
		embedder: emb,
		api:      coreAPI,
		tools:    exec,
		matcher:  matcher,
		replier:  replier,
		phraser:  phr,
		now:      time.Now,
		feedsOn:  cfg.Feeds != nil,
		home:     w.home,
		netscan:  w.netscan,
		// nil unless `crawl.on_demand` is on: reading a page he names is a
		// capability, and capabilities are off unless configured.
		crawler:          onDemandCrawler(cfg),
		weatherProvider:  weatherProvider,
		weatherLocation:  weatherLocation,
		memStore:         memStore,
		dataStore:        dataStore,
		dialogueSessions: dialogueSessions,
		clarifyStore:     clarifyStore,
		// 0 here (unset config) ⇒ the dialogue default.
		clarifyMaxAttempts: cfg.Voice.ClarifyMaxAttempts,
		extractor:          router.Extractor{Time: timeParser, Acts: matcher, Facts: router.DefaultFactParser{}},
		queryMinScore:      cfg.Voice.QueryMinScore,
		queryMinMargin:     cfg.Voice.QueryMinMargin,
		timeParser:         timeParser,
		ecosystem:          eco,
	}

	// ----- the server (TCP listener) -----
	srv := voice.NewServer(cfg.Voice.Bind, h, sessions)
	if err := srv.Listen(); err != nil {
		w.close()
		return nil, fmt.Errorf("voice listen: %w", err)
	}
	w.server = srv
	w.handler = h

	return w, nil
}

// pickLLMRouter returns the LLM router when the operator asked for it and there
// is a llama-server to talk to, and nil otherwise. nil is safe: the cascade then
// routes with the classifier, so an unusable setting costs accuracy, not turns.
func pickLLMRouter(enabled bool, c *llm.Client) *router.LLMRouter {
	if !enabled {
		return nil
	}
	if c == nil {
		log.Printf("voice: voice.llm_router is on but there is no llama-server to route with (the phraser is not an LLM phraser) — using the classifier instead")
		return nil
	}
	log.Printf("voice: LLM router enabled")
	return router.NewLLMRouter(c)
}

// buildRouter constructs the reactive-path router with the given embedder
// and confidence threshold.
//   - stage-0 grammars from DefaultActMatcher whose fn allowlist is exactly
//     the enabled tool names (actFns) — the router only matches acts the
//     executor can run. Empty ⇒ every act refuses at the matcher.
//   - The embedder is provided by wireVoice: HashEmbedder (floor) when no
//     embedder config is present, or the ONNX multilingual model when
//     configured — same interface, one constructor change.
//   - 6 bootstrap examples covering the 5 intents + one compound-capture
//     placeholder. Spec calls for ~10 per intent at production; this is the
//     bootstrapping floor swapped by tuning the seed set later.
//   - Threshold is from voice.router_threshold config (default 0.55).
func buildRouter(emb router.Embedder, acts router.ActMatcher, threshold float64, llmR *router.LLMRouter) *router.Router {
	cls := router.NewClassifier(emb)
	seedClassifier(cls)
	grammars := router.DefaultGrammars(acts)
	grammars = append(grammars, router.SystemTimeDateGrammars()...)
	grammars = append(grammars, router.ReminderGrammar())
	return router.New(router.Config{
		Grammars:   grammars,
		Classifier: cls,
		Extractor: router.Extractor{
			Time:  router.NewPythonDateParser(),
			Acts:  acts,
			Facts: router.DefaultFactParser{},
		},
		Threshold: threshold,
		LLM:       llmR,
	})
}

// seedDir is the directory containing intent seed files. Each file is named
// <intent>.txt and contains one training example per line (blank lines and
// lines starting with # are ignored). Relative to the working directory.
const seedDir = "models/seeds"

// seedClassifier floors the embedded examples so the cold-boot path
// doesn't return ErrNoIntents. Loads examples from seedDir — one file per
// intent (act.txt, reminder.txt, fact.txt, note.txt, query.txt). When the
// classifier can't decide it falls through to Clarify — the last-resort
// path asks the user to rephrase rather than guessing wrong.
func seedClassifier(c *router.Classifier) {
	intents := []router.Intent{
		router.IntentAct,
		router.IntentReminder,
		router.IntentFact,
		router.IntentNote,
		router.IntentQuery,
		router.IntentChat,
		router.IntentSystem,
	}
	total := 0
	for _, intent := range intents {
		n, err := loadSeedFile(c, intent)
		if err != nil {
			log.Printf("voice: seed %s: %v", intent, err)
			continue
		}
		total += n
	}
	log.Printf("voice: loaded %d seed examples from %s", total, seedDir)
}

func loadSeedFile(c *router.Classifier, intent router.Intent) (int, error) {
	path := filepath.Join(seedDir, string(intent)+".txt")
	f, err := os.Open(path)
	if err != nil {
		return 0, fmt.Errorf("open %s: %w", path, err)
	}
	defer f.Close()

	var count int
	sc := bufio.NewScanner(f)
	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		if err := c.AddExample(context.Background(), intent, line); err != nil {
			log.Printf("voice: seed %s: skipping %q: %v", intent, line, err)
			continue
		}
		count++
	}
	if err := sc.Err(); err != nil {
		return count, fmt.Errorf("scan %s: %w", path, err)
	}
	return count, nil
}

// seedTools upserts the config-declared tools into the store as enabled. Editing
// mavend.json is a human act, so a config tool is enabled by definition; this
// makes the declarative config the reproducible bootstrap while the store stays
// the single runtime source of truth (mavweb enables ad-hoc ones on top).
func seedTools(api ipc.CoreAPI, tools []config.ToolConfig) {
	ctx := context.Background()
	now := time.Now()
	n := 0
	for _, tc := range tools {
		if tc.Name == "" || len(tc.Cmd) == 0 {
			log.Printf("voice: skipping malformed tool config %+v", tc)
			continue
		}
		if err := api.EnableTool(ctx, tc.Name, tc.Cmd, tc.Destructive, tc.Scope, now); err != nil {
			log.Printf("voice: seed tool %q: %v", tc.Name, err)
			continue
		}
		n++
	}
	log.Printf("voice: seeded %d act tools from config", n)
}

// reembedOnStart is the -reembed flag (set in run()). Opt-in on purpose: see
// runReembed.
var reembedOnStart bool

// checkStoredEmbedder compares the embedder we just loaded with the one that
// wrote the vectors already in the DB (Vikunja #378).
//
// The two models we have both make 384-dim vectors, so a size check catches
// nothing: after a swap, recall silently compares vectors from different
// spaces and the scores are noise. So we say it out loud. Recall itself is not
// changed here — the fix is `mavend -reembed`.
func checkStoredEmbedder(dataStore *store.Store, emb router.Embedder) {
	if dataStore == nil {
		return
	}
	current := router.EmbedderID(emb)
	if reembedOnStart {
		runReembed(dataStore, emb, current)
		return
	}
	stored, mismatch, err := dataStore.CheckEmbedder(context.Background(), current)
	if err != nil {
		log.Printf("voice: embedder marker check failed: %v", err)
		return
	}
	if mismatch {
		log.Printf("voice: WARNING embedder MISMATCH — stored vectors were written by %q but the configured embedder is %q; recall scores are noise until the notes and facts are re-embedded — run `mavend -reembed` once (Vikunja #378)", stored, current)
		return
	}
	log.Printf("voice: embedder marker ok (%s)", current)
}

// runReembed is the one-shot backfill behind -reembed.
//
// Why a flag and not automatic on mismatch: the embedder is ONNX on the
// laptop's CPU, so a few thousand notes is minutes of work. Doing that silently
// inside a normal start would look like the daemon hanging on boot. So the user
// runs it once, deliberately, after an embedder swap; the mismatch warning
// above tells them to. It re-embeds, logs what it did, and then the daemon
// carries on serving as usual — no separate binary, no second start needed.
func runReembed(dataStore *store.Store, emb router.Embedder, current string) {
	log.Printf("voice: re-embedding stored notes and facts with %s — this can take a few minutes, do not interrupt", current)
	res, err := dataStore.ReembedAll(context.Background(), current,
		// EmbedPassage, not EmbedQuery: these are stored texts being searched
		// FOR, which is the side they were written with.
		func(ctx context.Context, text string) ([]float32, error) {
			return router.EmbedPassage(ctx, emb, text)
		})
	if err != nil {
		log.Printf("voice: re-embed FAILED, nothing was changed and no marker was written — safe to run again: %v", err)
		return
	}
	if res.Skipped {
		log.Printf("voice: re-embed skipped — the stored vectors were already written by %s", current)
		return
	}
	log.Printf("voice: re-embed done — %d notes in the notes table, %d notes and %d facts in the memory index, took %s; stored vectors now belong to %s",
		res.Notes, res.MemNotes, res.Facts, res.Took.Round(time.Second), current)

	// A row with no text cannot be re-embedded, so its vector is still the old
	// model's noise while the marker now says everything is current. Both write
	// paths always store the text, so this should be zero — say it loudly
	// rather than bury it in the line above if it ever isn't.
	if res.NoText > 0 {
		log.Printf("voice: WARNING %d stored rows had no text, so their vectors could not be re-embedded and are still noise; they will never match anything useful (Vikunja #378)", res.NoText)
	}
}