package membank

import (
	"encoding/json"
	"fmt"
	"sort"
	"strings"

	"textmachine/backend/internal/seed"
	"textmachine/backend/internal/store"
	"textmachine/backend/internal/text"
)

// memvoice.go: the two D21 bank record types pack-19 added — the per-character VOICE profile and the
// ordered ADDRESS pair — from seed file to store rows, plus the projection the flagger consumes.
//
// They are bank content and follow the bank's rules: curated only (no miner emits them), validated
// fail-loud at load (a silently inert profile is the class this bank exists to close), windowed on the
// SAME chapter axis as the spoiler window, and folded into the same memory_version.
//
// What they are NOT: matchable terms. A profile is keyed BY a character, it is not a surface to find in
// the text — so they never enter the Aho-Corasick automaton or the glossary injection. That separation
// is carried by the Go type system (BankInput.Rows is the only field Materialize matches over), not by a
// runtime filter that a later edit could forget.

// registerInformal / registerFormal are the ABSTRACT T/V vocabulary. They are typological category
// names, not target words: which surfaces realise them is target data, so a target with no T/V
// distinction ships no surfaces and the whole mechanism stays inert.
const (
	registerInformal = "informal"
	registerFormal   = "formal"
)

func validRegister(s string) bool { return s == registerInformal || s == registerFormal }

// BankSeed is one parsed seed file: the terms plus the two pack-19 record types.
type BankSeed struct {
	Terms  []store.GlossaryEntry
	Voices []store.VoiceProfile
	Pairs  []store.AddressPair
}

// LoadGlossarySeed parses the TERMS of a seed file — the pre-pack-19 entry point, kept for every caller
// that has no use for the other two record types.
func LoadGlossarySeed(path string) ([]store.GlossaryEntry, error) {
	s, err := LoadBankSeed(path)
	if err != nil {
		return nil, err
	}
	return s.Terms, nil
}

// loadVoiceSections validates and materializes the voices:/addresses: sections of a parsed seed file.
// Fail-loud on anything that would be silently inert or would crash the UNIQUE constraint mid-run, which
// is the same contract the terms half keeps.
func loadVoiceSections(path string, sf *seed.File) ([]store.VoiceProfile, []store.AddressPair, error) {
	var problems []string
	var voices []store.VoiceProfile
	voiceKeys := map[[4]string]bool{}
	for i, v := range sf.Voices {
		src, sense := strings.TrimSpace(v.Src), strings.TrimSpace(v.Sense)
		if src == "" {
			problems = append(problems, fmt.Sprintf("voice %d: src is required (it names the glossary term this profile belongs to)", i))
			continue
		}
		if d := strings.TrimSpace(v.AddressDefault); d != "" && !validRegister(d) {
			problems = append(problems, fmt.Sprintf("voice %q: address_default must be %s|%s, got %q", src, registerInformal, registerFormal, d))
			continue
		}
		k := [4]string{src, sense, fmt.Sprint(v.SinceCh), fmt.Sprint(v.UntilCh)}
		if voiceKeys[k] {
			problems = append(problems, fmt.Sprintf("voice %q: duplicate (src, sense=%q, since_ch=%d, until_ch=%d) — a character has one profile per window", src, sense, v.SinceCh, v.UntilCh))
			continue
		}
		voiceKeys[k] = true
		markers, err := cleanList(v.LexiconMarkers, "voice "+src+" lexicon_markers")
		if err != nil {
			problems = append(problems, err.Error())
			continue
		}
		ng, err := cleanList(v.NGLexicon, "voice "+src+" ng_lexicon")
		if err != nil {
			problems = append(problems, err.Error())
			continue
		}
		ex, err := cleanList(v.Exemplars, "voice "+src+" exemplars")
		if err != nil {
			problems = append(problems, err.Error())
			continue
		}
		// A profile that states NOTHING is an authoring slip: it costs a bank row and a hash, and directs
		// nothing. Refused for the same reason an empty langpack table is (never silently empty).
		if strings.TrimSpace(v.Register) == "" && strings.TrimSpace(v.SelfRef) == "" &&
			strings.TrimSpace(v.AddressDefault) == "" && len(markers) == 0 && len(ng) == 0 && len(ex) == 0 {
			problems = append(problems, fmt.Sprintf("voice %q: the profile states nothing (needs at least one of register|self_ref|address_default|lexicon_markers|ng_lexicon|exemplars)", src))
			continue
		}
		voices = append(voices, store.VoiceProfile{
			Src: src, Sense: sense,
			Register: strings.TrimSpace(v.Register), SelfRef: strings.TrimSpace(v.SelfRef),
			AddressDefault: strings.TrimSpace(v.AddressDefault),
			LexiconMarkers: encodeList(markers), NGLexicon: encodeList(ng), Exemplars: encodeList(ex),
			Brightness: strings.TrimSpace(v.Brightness), SinceCh: v.SinceCh, UntilCh: v.UntilCh,
		})
	}
	// Two profiles of one character valid at the same chapter: the projection would have to pick, and it
	// has no basis to. Same rule, same reason, as two renderings of one term in one chapter.
	for i := range voices {
		for j := 0; j < i; j++ {
			a, b := voices[i], voices[j]
			if a.Src == b.Src && a.Sense == b.Sense && windowsOverlap(a.SinceCh, a.UntilCh, b.SinceCh, b.UntilCh) {
				problems = append(problems, fmt.Sprintf("voice %q: windows [%d,%d] and [%d,%d] overlap — a character has ONE profile per chapter",
					a.Src, b.SinceCh, b.UntilCh, a.SinceCh, a.UntilCh))
			}
		}
	}

	var pairs []store.AddressPair
	pairKeys := map[[6]string]bool{}
	for i, p := range sf.Addresses {
		sp, spSense := strings.TrimSpace(p.Speaker), strings.TrimSpace(p.SpeakerSense)
		ad, adSense := strings.TrimSpace(p.Addressee), strings.TrimSpace(p.AddresseeSense)
		if sp == "" || ad == "" {
			problems = append(problems, fmt.Sprintf("address %d: speaker and addressee are both required", i))
			continue
		}
		if sp == ad && spSense == adSense {
			problems = append(problems, fmt.Sprintf("address %q: speaker and addressee are the same character — a register is a fact about a PAIR", sp))
			continue
		}
		if !validRegister(strings.TrimSpace(p.Register)) {
			problems = append(problems, fmt.Sprintf("address %q→%q: register must be %s|%s, got %q (the value is a typological category, never a target word)",
				sp, ad, registerInformal, registerFormal, p.Register))
			continue
		}
		k := [6]string{sp, spSense, ad, adSense, fmt.Sprint(p.SinceCh), fmt.Sprint(p.UntilCh)}
		if pairKeys[k] {
			problems = append(problems, fmt.Sprintf("address %q→%q: duplicate (speaker, addressee, since_ch=%d, until_ch=%d)", sp, ad, p.SinceCh, p.UntilCh))
			continue
		}
		pairKeys[k] = true
		pairs = append(pairs, store.AddressPair{
			SpeakerSrc: sp, SpeakerSense: spSense, AddresseeSrc: ad, AddresseeSense: adSense,
			Register: strings.TrimSpace(p.Register), Form: strings.TrimSpace(p.Form),
			Closeness: strings.TrimSpace(p.Closeness), SinceCh: p.SinceCh, UntilCh: p.UntilCh,
		})
	}
	// Contradictory registers for one ordered pair at one chapter. A ты↔вы switch is legitimate — as a
	// SECOND row with a non-overlapping window, which is what makes the table a journal.
	for i := range pairs {
		for j := 0; j < i; j++ {
			a, b := pairs[i], pairs[j]
			if a.SpeakerSrc != b.SpeakerSrc || a.SpeakerSense != b.SpeakerSense ||
				a.AddresseeSrc != b.AddresseeSrc || a.AddresseeSense != b.AddresseeSense {
				continue
			}
			if a.Register != b.Register && windowsOverlap(a.SinceCh, a.UntilCh, b.SinceCh, b.UntilCh) {
				problems = append(problems, fmt.Sprintf("address %q→%q: registers %q [%d,%d] and %q [%d,%d] overlap — one pair has ONE register per chapter (a switch is a new window, not an overlap)",
					a.SpeakerSrc, a.AddresseeSrc, b.Register, b.SinceCh, b.UntilCh, a.Register, a.SinceCh, a.UntilCh))
			}
		}
	}
	if len(problems) > 0 {
		return nil, nil, fmt.Errorf("glossary seed %s:\n  - %s", path, strings.Join(problems, "\n  - "))
	}
	return voices, pairs, nil
}

// cleanList trims a seed string list and refuses an empty member: a blank exemplar or marker is an
// authoring slip that would inject an empty line and count toward a budget.
func cleanList(in []string, what string) ([]string, error) {
	var out []string
	for _, s := range in {
		t := strings.TrimSpace(s)
		if t == "" {
			return nil, fmt.Errorf("%s: an entry is empty", what)
		}
		out = append(out, t)
	}
	return out, nil
}

// encodeList renders a string list as the JSON stored in a column. Empty → "" (not "null"/"[]"), so an
// unstated field costs no bytes in the row and none in the hash.
func encodeList(in []string) string {
	if len(in) == 0 {
		return ""
	}
	b, err := json.Marshal(in)
	if err != nil { // a []string cannot fail to marshal
		return ""
	}
	return string(b)
}

// decodeList reads a stored JSON list back. A malformed blob yields nil rather than an error: the column
// is written by encodeList alone, so a bad value is impossible without direct DB surgery, and the
// flagger's honest answer to "no data" is to check nothing.
func decodeList(s string) []string {
	if strings.TrimSpace(s) == "" {
		return nil
	}
	var out []string
	if json.Unmarshal([]byte(s), &out) != nil {
		return nil
	}
	return out
}

// UnknownVoiceCharacters reports voice/address rows whose (src, sense) names no term in the bank. Such a
// row is silently inert — the character has no target surfaces, so nothing can ever attribute a reply to
// it — which is exactly the A-class hole the bank exists to close, so the caller fails the run loud.
// Checked over the FULL entry set (seed + ruby + mined + auto), because a character may legitimately be
// signed in a delta rather than the base seed. Deterministic (input order).
func UnknownVoiceCharacters(entries []store.GlossaryEntry, voices []store.VoiceProfile, pairs []store.AddressPair) []string {
	known := map[[2]string]bool{}
	for _, e := range entries {
		known[[2]string{e.Src, e.Sense}] = true
	}
	var out []string
	seen := map[string]bool{}
	add := func(msg string) {
		if !seen[msg] {
			seen[msg] = true
			out = append(out, msg)
		}
	}
	for _, v := range voices {
		if !known[[2]string{v.Src, v.Sense}] {
			add(fmt.Sprintf("voice profile %q (sense %q) names no term in the bank", v.Src, v.Sense))
		}
	}
	for _, p := range pairs {
		if !known[[2]string{p.SpeakerSrc, p.SpeakerSense}] {
			add(fmt.Sprintf("address speaker %q (sense %q) names no term in the bank", p.SpeakerSrc, p.SpeakerSense))
		}
		if !known[[2]string{p.AddresseeSrc, p.AddresseeSense}] {
			add(fmt.Sprintf("address addressee %q (sense %q) names no term in the bank", p.AddresseeSrc, p.AddresseeSense))
		}
	}
	return out
}

// VoiceWindowGaps reports a character whose profiles leave a chapter UNCOVERED between two windows
// (…until_ch=10 then since_ch=20: chapters 11–19 have no voice at all). Not an error — a deliberate gap
// is legitimate — but it is invisible in a seed file and is far more often a typo, so the caller logs it.
// The optional lint D39.55 asked for, applied where the data actually is.
func VoiceWindowGaps(voices []store.VoiceProfile) []string {
	byChar := map[[2]string][]store.VoiceProfile{}
	var order [][2]string
	for _, v := range voices {
		k := [2]string{v.Src, v.Sense}
		if _, ok := byChar[k]; !ok {
			order = append(order, k)
		}
		byChar[k] = append(byChar[k], v)
	}
	var out []string
	for _, k := range order {
		win := byChar[k]
		if len(win) < 2 {
			continue
		}
		sort.Slice(win, func(i, j int) bool { return win[i].SinceCh < win[j].SinceCh })
		for i := 1; i < len(win); i++ {
			prevUntil := win[i-1].UntilCh
			if prevUntil == 0 { // open-ended: nothing after it can be a gap
				continue
			}
			if win[i].SinceCh > prevUntil+1 {
				out = append(out, fmt.Sprintf("voice %q: chapters %d–%d have no profile (window ends at %d, next starts at %d)",
					k[0], prevUntil+1, win[i].SinceCh-1, prevUntil, win[i].SinceCh))
			}
		}
	}
	return out
}

// CharacterView is one character as an OUTPUT-side checker needs to see it: an opaque identity, the
// normalized target surfaces that name it, and the two profile fields the deterministic checks read. It
// is deliberately free of store and checker types — membank owns the projection, the driver owns the
// adaptation — so neither package has to know the other's vocabulary.
type CharacterView struct {
	Key     string // src\x1fsense — compared, never rendered into a message
	Name    string // the approved rendering, for a human-readable detail line
	Forms   []string
	SelfRef string
	NG      []string
}

// AddressView is one ordered register record projected onto a chapter.
type AddressView struct {
	Speaker, Addressee, Register string // Speaker/Addressee are CharacterView.Key
}

// VoiceProjection resolves the bank's voice/address content ONTO one chapter: the profiles and register
// records whose window contains it, joined to the terms that give each character its target surfaces.
//
// It is a PROJECTION, never stored state — which is what keeps address_pairs a journal with one source
// of truth (D21 п.2) instead of a second store that could disagree with it. A character whose term is
// spoiler-blocked at this chapter is dropped entirely: it cannot be matched in the output, so a profile
// for it could only produce noise. Pure and deterministic (bank order).
func (b *Bank) VoiceProjection(chapter int) ([]CharacterView, []AddressView) {
	if b == nil {
		return nil, nil
	}
	// The character's surfaces come from the term row valid at this chapter (the same window rule the
	// injection uses), so a pre/post-reveal handoff projects the rendering the chapter is allowed to see.
	forms := func(src, sense string) (view CharacterView, ok bool) {
		for i := range b.entries {
			e := &b.entries[i]
			if e.src != src || e.sense != sense || spoilerBlocked(e, chapter) {
				continue
			}
			base := text.NormalizeTargetForm(e.dst)
			if base == "" {
				continue
			}
			view.Key = src + "\x1f" + sense
			view.Name = e.dst
			view.Forms = append([]string{base}, e.declForms...)
			return view, true
		}
		return view, false
	}
	byKey := map[string]*CharacterView{}
	var chars []CharacterView
	order := []string{}
	need := func(src, sense string) *CharacterView {
		key := src + "\x1f" + sense
		if v, ok := byKey[key]; ok {
			return v
		}
		v, ok := forms(src, sense)
		if !ok {
			byKey[key] = nil
			return nil
		}
		byKey[key] = &v
		order = append(order, key)
		return &v
	}
	for _, vp := range b.voices {
		if vp.SinceCh > 0 && chapter < vp.SinceCh {
			continue
		}
		if vp.UntilCh > 0 && chapter > vp.UntilCh {
			continue
		}
		v := need(vp.Src, vp.Sense)
		if v == nil {
			continue
		}
		v.SelfRef = text.NormalizeTargetForm(vp.SelfRef)
		for _, w := range decodeList(vp.NGLexicon) {
			if n := text.NormalizeTargetForm(w); n != "" {
				v.NG = append(v.NG, n)
			}
		}
	}
	var addrs []AddressView
	for _, p := range b.pairs {
		if p.SinceCh > 0 && chapter < p.SinceCh {
			continue
		}
		if p.UntilCh > 0 && chapter > p.UntilCh {
			continue
		}
		sp, ad := need(p.SpeakerSrc, p.SpeakerSense), need(p.AddresseeSrc, p.AddresseeSense)
		if sp == nil || ad == nil {
			continue
		}
		addrs = append(addrs, AddressView{Speaker: sp.Key, Addressee: ad.Key, Register: p.Register})
	}
	for _, k := range order {
		chars = append(chars, *byKey[k])
	}
	return chars, addrs
}