package autogen

// YAML emission helpers: the non-model sections of the generated config
// (slot cache, API keys, groups, listeners) plus the small per-model bits
// (display name, profile block, id slug/tag formatting).

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"sync"
	"time"

	"gopkg.in/yaml.v3"

	"github.com/quartermaster-labs/quartermaster/internal/apppaths"
)

// slotKvPath resolves the slot-cache snapshot dir as forward-slash text shared
// by the --slot-save-path flag and the emitted slotCache.path. A blank Path
// falls back to the shared cache directory -- the same one
// config.DefaultSlotCachePath returns, which is what keeps the emitted config
// and the server's own LRU pointed at one directory. Both resolve it through
// internal/apppaths so autogen still needs no internal/config import.
func slotKvPath(sc SlotCacheSettings) string {
	p := sc.Path
	if p == "" {
		p = filepath.Join(apppaths.CacheDir(), "slotkv")
	}
	return strings.ReplaceAll(p, "\\", "/")
}

// multiResidentOn reports whether VRAM-budget multi-load is enabled (default on).
func multiResidentOn(s Settings) bool {
	return s.MultiResident == nil || *s.MultiResident
}

// emitVramBudget writes the top-level vramBudgetGB the router admits against.
// Withheld when multiResident is off, which leaves the router on the legacy
// static swap/exclusive policy even though every model still carries its
// estVramGB (harmless, and it keeps the dashboard's numbers available).
func emitVramBudget(b *strings.Builder, s Settings) {
	if !multiResidentOn(s) || s.TargetVramGB <= 0 {
		return
	}
	b.WriteString("# multi-resident: models stay loaded side by side while their\n")
	b.WriteString("# estVramGB sum fits this budget; over it, the least-recently-used\n")
	b.WriteString("# ones are evicted until the incoming model fits.\n")
	fmt.Fprintf(b, "vramBudgetGB: %g\n\n", round2(s.TargetVramGB))
}

// emitRamBudget writes ramBudgetGB, the RAM pool's admission budget (see
// config.Config.RamBudgetGB), from settings.maxRamGB. Same multiResident gate
// as the VRAM one.
func emitRamBudget(b *strings.Builder, s Settings) {
	if !multiResidentOn(s) || s.MaxRamGB <= 0 {
		return
	}
	b.WriteString("# CPU-pool models are admitted while every resident's estRamGB fits\n")
	b.WriteString("# this budget; over it, the least-recently-used CPU-pool ones go.\n")
	fmt.Fprintf(b, "ramBudgetGB: %g\n\n", round2(s.MaxRamGB))
}

// writeEstVram emits a model's predicted VRAM footprint, the admission input for
// vramBudgetGB. Omitted when the caller has no estimate (0), which the router
// reads as "unknown" and handles conservatively.
func writeEstVram(b *strings.Builder, estGB float64) {
	if estGB <= 0 {
		return
	}
	fmt.Fprintf(b, "    estVramGB: %g\n", round2(estGB))
}

// writeEstRam emits the sizer's predicted RAM share (weights the GPU could not
// take, or the whole footprint of a CPU-device model). It is the admission
// input for ramBudgetGB, and is omitted for a fully-offloaded model rather than
// written as 0.
func writeEstRam(b *strings.Builder, estGB float64) {
	if estGB <= 0 {
		return
	}
	fmt.Fprintf(b, "    estRamGB: %g\n", round2(estGB))
}

// emitSlotCache writes the slotCache config block (consumed by the server) when
// the feature is enabled. Unset knobs are omitted so the server applies its
// defaults. The path is always emitted so it matches the --slot-save-path flag.
func emitSlotCache(b *strings.Builder, sc SlotCacheSettings) {
	if !sc.Enable {
		return
	}
	b.WriteString("slotCache:\n")
	b.WriteString("  enable: true\n")
	fmt.Fprintf(b, "  path: %q\n", slotKvPath(sc))
	if sc.MinSaveTokens > 0 {
		fmt.Fprintf(b, "  minSaveTokens: %d\n", sc.MinSaveTokens)
	}
	if sc.RecurrentSeeds {
		b.WriteString("  recurrentSeeds: true\n")
	}
	if sc.MaxDiskGB > 0 {
		fmt.Fprintf(b, "  maxDiskGB: %g\n", sc.MaxDiskGB)
	}
	if sc.MaxSessions > 0 {
		fmt.Fprintf(b, "  maxSessions: %d\n", sc.MaxSessions)
	}
	if sc.MaxIdleDays > 0 {
		fmt.Fprintf(b, "  maxIdleDays: %d\n", sc.MaxIdleDays)
	}
	// Only the off case is emitted: absent means on, matching config's *bool.
	if sc.PreambleCaches != nil && !*sc.PreambleCaches {
		b.WriteString("  preambleCaches: false\n")
	}
	b.WriteString("\n")
}

// enhancerByID indexes settings.promptEnhancers by lowercased model id, which is
// how both the emitter and the per-model resolver look one up. Later entries win
// over earlier ones with the same id: a duplicate is an edit that was appended
// rather than replaced, and the last word is the one the user just wrote.
//
// Entries naming no model are dropped rather than reported. The list is UI-owned
// (the Settings page appends a blank row before it is filled in), so a half-typed
// entry is a normal intermediate state, not a config error.
func enhancerByID(list []PromptEnhancer) map[string]PromptEnhancer {
	if len(list) == 0 {
		return nil
	}
	out := make(map[string]PromptEnhancer, len(list))
	for _, e := range list {
		id := strings.ToLower(strings.TrimSpace(e.Model))
		if id == "" {
			continue
		}
		out[id] = e
	}
	if len(out) == 0 {
		return nil
	}
	return out
}

// emitPromptEnhancers writes the top-level promptEnhancers map: the rewrite
// models an image model may hand its prompt to, each with the fixed system
// prompt it was trained under.
//
// The body is marshalled by yaml.v3 rather than Fprintf'd like every other block
// in this file, for one reason: a PE system prompt is a multi-KB, multi-line,
// quote-and-backslash-bearing document the publisher ships verbatim, and
// hand-rolling a block scalar for it is exactly the kind of quoting that works on
// the example and corrupts the real thing. The marshaller picks a safe
// representation (block scalar, quoted, whatever the content needs); we only
// indent it.
//
// Emitted in sorted id order so a regeneration with no changes produces an
// identical file - the config hash is what gates a reload.
func emitPromptEnhancers(b *strings.Builder, list []PromptEnhancer) {
	byID := enhancerByID(list)
	if len(byID) == 0 {
		return
	}
	ids := make([]string, 0, len(byID))
	for id := range byID {
		ids = append(ids, id)
	}
	sort.Strings(ids)

	b.WriteString("# prompt-rewrite models an image model may delegate to before it renders.\n")
	b.WriteString("# Consumed by the CLIENT (the playground's Enhance button), never by the\n")
	b.WriteString("# image route: a rewrite you cannot see or edit before it renders is worse\n")
	b.WriteString("# than none. A model opts in with its own promptEnhancer: <id>.\n")
	b.WriteString("promptEnhancers:\n")
	for _, id := range ids {
		e := byID[id]
		body := struct {
			Name         string `yaml:"name,omitempty"`
			Vision       bool   `yaml:"vision,omitempty"`
			SystemPrompt string `yaml:"systemPrompt,omitempty"`
		}{Name: strings.TrimSpace(e.Name), Vision: e.Vision, SystemPrompt: e.SystemPrompt}
		out, err := yaml.Marshal(body)
		if err != nil {
			// Unreachable for a struct of two strings and a bool, but a marshal
			// error must not take the whole config with it: skip the entry and say
			// so, leaving every other model generated and loadable.
			fmt.Fprintf(b, "  # SKIPPED prompt enhancer %q: %v\n", e.Model, err)
			continue
		}
		fmt.Fprintf(b, "  %q:\n", strings.TrimSpace(e.Model))
		b.WriteString(indentYAML(string(out), "    "))
	}
	b.WriteString("\n")
}

// indentYAML shifts a marshalled block right by prefix. Blank lines are left
// EMPTY rather than filled with the prefix: a block scalar's interior blank line
// is part of its value, and padding it with spaces would silently add trailing
// whitespace to a system prompt.
func indentYAML(doc, prefix string) string {
	var b strings.Builder
	// TrimSuffix, not TrimRight: yaml.Marshal terminates the document with exactly
	// one newline, and every newline before that one is CONTENT. A system prompt
	// ending in a blank line marshals to a "|+" keep-indicator block, and trimming
	// the run would silently drop the bytes that indicator exists to preserve.
	for _, line := range strings.Split(strings.TrimSuffix(doc, "\n"), "\n") {
		if line == "" {
			b.WriteString("\n")
			continue
		}
		b.WriteString(prefix)
		b.WriteString(line)
		b.WriteString("\n")
	}
	return b.String()
}

// ovPromptEnhancer reads an override's enhancer id nil-safely. Most emitters in
// this package take *Override and a nil one is the ordinary "no rule matched"
// case, not an error.
func ovPromptEnhancer(ov *Override) string {
	if ov == nil {
		return ""
	}
	return ov.PromptEnhancer
}

// ovPromptEnhancerEdit is the img2img half, same nil-safety.
func ovPromptEnhancerEdit(ov *Override) string {
	if ov == nil {
		return ""
	}
	return ov.PromptEnhancerEdit
}

// ovEnhancerPrompt / ovEnhancerEditPrompt read the per-model system prompts,
// same nil-safety.
func ovEnhancerPrompt(ov *Override) string {
	if ov == nil {
		return ""
	}
	return ov.PromptEnhancerPrompt
}

func ovEnhancerEditPrompt(ov *Override) string {
	if ov == nil {
		return ""
	}
	return ov.PromptEnhancerEditPrompt
}

// writePromptEnhancer emits a model's `promptEnhancer:` line - the id of the
// rewrite model it delegates its prompt to.
func writePromptEnhancer(b *strings.Builder, id string, byID map[string]PromptEnhancer) {
	writeEnhancerKey(b, "promptEnhancer", id, byID)
}

// writePromptEnhancerEdit emits the img2img half. Written independently of the
// text one: a model may configure either, both or neither, and the client falls
// back to whichever is present.
func writePromptEnhancerEdit(b *strings.Builder, id string, byID map[string]PromptEnhancer) {
	writeEnhancerKey(b, "promptEnhancerEdit", id, byID)
}

// writeEnhancerBlock emits a model's whole prompt-enhancer wiring: the id it
// uses per direction, plus the system prompt IT wants that enhancer to run
// under. imageID is the model's discovered id (not its emitted name), which is
// what the detection table is keyed on.
func writeEnhancerBlock(b *strings.Builder, s Settings, imageID, text, edit, textPrompt, editPrompt string) {
	text, edit = resolveEnhancerIDs(s, imageID, text, edit)
	byID := enhancerByID(s.PromptEnhancers)
	writePromptEnhancer(b, text, byID)
	writePromptEnhancerEdit(b, edit, byID)
	writeEnhancerPrompt(b, "promptEnhancerPrompt", text, textPrompt)
	writeEnhancerPrompt(b, "promptEnhancerEditPrompt", edit, editPrompt)
}

// writeEnhancerKey emits one enhancer id, as typed.
//
// A settings.promptEnhancers row is NOT required. It used to be - an id with no
// row was dropped here - and that was wrong in both directions the feature grew:
// an id can now be free text the user typed (the modal says so: "it will be
// called with no system prompt") or one this package detected from a filename,
// and in both cases the system prompt lives on the IMAGE model. Dropping the id
// meant the client showed no button and nothing said why. A row, when there is
// one, now only fixes up the canonical casing of the id it declares.
func writeEnhancerKey(b *strings.Builder, key, id string, byID map[string]PromptEnhancer) {
	id = strings.TrimSpace(id)
	if id == "" || enhancerDisabled(id) {
		return
	}
	if e, ok := byID[strings.ToLower(id)]; ok {
		id = strings.TrimSpace(e.Model)
	}
	fmt.Fprintf(b, "    %s: %q\n", key, id)
}

// writeEnhancerPrompt emits a model's OWN system prompt for one direction: the
// text pasted into the model modal's prompt dialog. Skipped when the model has
// no enhancer in that direction, since the prompt would have nothing to run
// under.
//
// Marshalled rather than Fprintf'd for the same reason emitPromptEnhancers is: a
// rewriter prompt is a multi-line document full of quotes, colons and
// backslashes, and hand-rolling a block scalar for it works on the example and
// corrupts the real thing.
func writeEnhancerPrompt(b *strings.Builder, key, id, prompt string) {
	if strings.TrimSpace(id) == "" || enhancerDisabled(id) || prompt == "" {
		return
	}
	out, err := yaml.Marshal(map[string]string{key: prompt})
	if err != nil {
		// Unreachable for a one-string map, but a marshal error must not take the
		// model with it: the enhancer falls back to the shared row's prompt.
		fmt.Fprintf(b, "    # SKIPPED %s: %v\n", key, err)
		return
	}
	b.WriteString(indentYAML(string(out), "    "))
}

// emitAPIKeys writes the apiKeys list and, for any key scoped to a model
// subset, the apiKeyModels map (key => allowed model IDs). Keys with no Models
// are unrestricted and appear only in apiKeys. No keys => nothing emitted.
func emitAPIKeys(b *strings.Builder, keys []APIKeyEntry) {
	if len(keys) == 0 {
		return
	}
	b.WriteString("apiKeys:\n")
	for _, k := range keys {
		fmt.Fprintf(b, "  - %q\n", k.Key)
	}
	scoped := false
	for _, k := range keys {
		if len(k.Models) > 0 {
			scoped = true
			break
		}
	}
	if scoped {
		b.WriteString("apiKeyModels:\n")
		for _, k := range keys {
			if len(k.Models) == 0 {
				continue
			}
			fmt.Fprintf(b, "  %q:\n", k.Key)
			for _, m := range k.Models {
				fmt.Fprintf(b, "    - %q\n", m)
			}
		}
	}
	b.WriteString("\n")
}

// emitGroupsAndListeners writes the groups block and, when settings.groups
// define listen addresses, a listeners block. The mechanism is use-case
// agnostic: each configured group has name-glob patterns (PowerShell -like);
// every emitted model is assigned to the FIRST group whose any pattern matches
// its name, so put specific groups before a "*" catch-all. Models matching no
// group fall into an implicit "default" group with no listener. Every group is
// exclusive, so loading on any listener still evicts whatever the others were
// running (one GPU, VRAM-exclusive); a group marked coexist additionally keeps its
// OWN members loaded side by side (swap:false) instead of swapping between them.
// With no settings.groups the output is a single "exclusive" group over every model
// (upstream default).
func emitGroupsAndListeners(b *strings.Builder, s Settings, emitted []string, cs coexistSets) {
	// SAM masks, CPU-only TTS.cpp voices and CPU-only Parakeet ASR models are tiny,
	// cost no VRAM, and are wanted ALONGSIDE whatever LLM/image model is loaded — a
	// read-aloud click or a dictation must not swap the chat model out. They go in
	// their own never-evicting groups (see writeCoexistGroup) and are kept out of
	// the exclusive swap groups below.
	groups := cs.groups(s)
	inCoexist := map[string]bool{}
	for _, g := range groups {
		for _, n := range g.members {
			inCoexist[n] = true
		}
	}
	swappable := emitted
	if len(inCoexist) > 0 {
		swappable = swappable[:0:0]
		for _, n := range emitted {
			if !inCoexist[n] {
				swappable = append(swappable, n)
			}
		}
	}

	if len(s.Groups) == 0 {
		b.WriteString("\ngroups:\n")
		writeGroup(b, "exclusive", swappable, false)
		for _, g := range groups {
			writeCoexistGroup(b, g.name, g.members, g.ramPool)
		}
		return
	}
	coexist := make(map[string]bool, len(s.Groups))
	for _, g := range s.Groups {
		if g.Coexist {
			coexist[g.Name] = true
		}
	}

	// Assign each model to the first matching group (config order preserved).
	members := make(map[string][]string, len(s.Groups)+1)
	order := make([]string, 0, len(s.Groups)+1)
	seenGroup := map[string]bool{}
	addGroup := func(name string) {
		if !seenGroup[name] {
			seenGroup[name] = true
			order = append(order, name)
		}
	}
	for _, g := range s.Groups {
		addGroup(g.Name)
	}
	const defaultGroup = "default"
	for _, name := range swappable {
		assigned := ""
		for _, g := range s.Groups {
			for _, pat := range g.Match {
				if globLike(pat, name) {
					assigned = g.Name
					break
				}
			}
			if assigned != "" {
				break
			}
		}
		if assigned == "" {
			assigned = defaultGroup
			addGroup(defaultGroup)
		}
		members[assigned] = append(members[assigned], name)
	}

	b.WriteString("\ngroups:\n")
	for _, name := range order {
		writeGroup(b, name, members[name], coexist[name])
	}
	for _, g := range groups {
		writeCoexistGroup(b, g.name, g.members, g.ramPool)
	}

	// listeners: address -> the groups it exposes (a group with no Listen binds
	// no dedicated port but still groups for eviction). The coexistence groups carry
	// no Listen of their own, so they are appended to EVERY listener: a curated port
	// must not lose its segmentation / read-aloud models purely because we moved them
	// out of the exclusive group.
	byAddr := map[string][]string{}
	var addrOrder []string
	for _, g := range s.Groups {
		if g.Listen == "" {
			continue
		}
		if _, ok := byAddr[g.Listen]; !ok {
			addrOrder = append(addrOrder, g.Listen)
		}
		byAddr[g.Listen] = append(byAddr[g.Listen], g.Name)
	}
	if len(addrOrder) == 0 {
		return
	}
	var everywhere []string
	for _, g := range groups {
		everywhere = append(everywhere, g.name)
	}
	b.WriteString("\nlisteners:\n")
	for _, addr := range addrOrder {
		groups := append(append([]string{}, byAddr[addr]...), everywhere...)
		fmt.Fprintf(b, "  %q:\n    groups: [%s]\n", addr, strings.Join(groups, ", "))
	}
}

// coexistSets carries the model classes that must never take part in eviction:
// they are tiny, run outside the VRAM budget, and are used WHILE a chat or image
// model is resident. Sam is GPU-capable but placed live (see liveoffload.go); the
// other two are CPU-only unless the user opts into GPU via extraArgs, an accepted
// under-charge — the alternative is evicting a 27B on every dictation.
type coexistSets struct {
	Sam []string // SAM segmentation (*.ggml, sam3_server)
	TTS []string // TTS.cpp voices (Kokoro & friends) — CPU-only, no CUDA/ROCm path
	ASR []string // Parakeet transcription — CPU-only by default
	// CPU holds models the user pinned to the RAM pool (Override.InCpuPool). Not
	// a never-evict group like the three above: its members can be big, so they
	// are admitted against ramBudgetGB and evict each other LRU-first, but never
	// evict, and are never evicted by, a GPU model for VRAM.
	CPU []string
}

// coexistGroup is one emitted never-evicting group. Empty ones are dropped, so a
// config with no ASR models carries no "asr" group and no listener reference.
type coexistGroup struct {
	name    string
	members []string
	ramPool bool // the RAM-budgeted cpu group, see writeCoexistGroup
}

func (cs coexistSets) groups(s Settings) []coexistGroup {
	var out []coexistGroup
	for _, g := range []coexistGroup{
		{"sam", cs.Sam, false},
		{"tts", cs.TTS, false},
		{"asr", cs.ASR, false},
		{cpuGroupName, cs.CPU, true},
	} {
		if len(g.members) > 0 {
			out = append(out, coexistGroup{freeGroupName(s, g.name), g.members, g.ramPool})
		}
	}
	return out
}

// freeGroupName returns want, or want+"-auto" when a settings group already claims
// that name. The coexistence groups are synthesised by us, and emitting a duplicate
// YAML key would silently drop the user's group of the same name.
func freeGroupName(s Settings, want string) string {
	for _, g := range s.Groups {
		if strings.EqualFold(strings.TrimSpace(g.Name), want) {
			return want + "-auto"
		}
	}
	return want
}

// writeCoexistGroup emits a zero-VRAM coexistence group (SAM segmentation, CPU-only
// TTS.cpp voices, CPU-only Parakeet ASR): exclusive:false so loading a member evicts nothing,
// persistent:true so an exclusive LLM/image load never evicts the members,
// swap:false so several members coexist (they're all tiny). Nothing is emitted when
// the group has no members.
//
// The cpu group (ramPool) differs: swap:true and not persistent, so without a
// RAM budget its members still swap among themselves (one resident) instead of
// piling up in RAM forever, and with one the router admits them by fit. pool:
// ram is what keeps a GPU load from ever evicting them for VRAM.
func writeCoexistGroup(b *strings.Builder, name string, members []string, ramPool bool) {
	if len(members) == 0 {
		return
	}
	fmt.Fprintf(b, "  %s:\n", name)
	if ramPool {
		b.WriteString("    swap: true\n")
		b.WriteString("    exclusive: false\n")
		b.WriteString("    persistent: false\n")
		b.WriteString("    pool: ram\n")
	} else {
		b.WriteString("    swap: false\n")
		b.WriteString("    exclusive: false\n")
		b.WriteString("    persistent: true\n")
	}
	b.WriteString("    members:\n")
	for _, n := range members {
		fmt.Fprintf(b, "      - %q\n", n)
	}
}

// writeGroup emits one exclusive group with the given members. swap:true (the
// default) means only one member is loaded at a time; coexist emits swap:false so
// the members stay resident together. Either way exclusive:true keeps the group
// evicting the OTHER groups — one GPU.
func writeGroup(b *strings.Builder, name string, members []string, coexist bool) {
	fmt.Fprintf(b, "  %s:\n", name)
	if coexist {
		b.WriteString("    swap: false\n")
	} else {
		b.WriteString("    swap: true\n")
	}
	b.WriteString("    exclusive: true\n")
	b.WriteString("    members:\n")
	for _, n := range members {
		fmt.Fprintf(b, "      - %q\n", n)
	}
}

// emitProfile writes one model entry's YAML block.
// resolvePublicName returns the advertised name for a served id when its base
// model was renamed via settings.displayNames: the display name plus the served
// id's variant suffix. The map is keyed by BASE id; the longest matching base
// prefix wins so a renamed "foo" doesn't shadow a separately-renamed "foo-bar".
// "" => not renamed (advertise the real id unchanged).
func resolvePublicName(dn map[string]string, id string) string {
	best, bestName := "", ""
	for base, name := range dn {
		if strings.TrimSpace(name) == "" {
			continue
		}
		if id == base || strings.HasPrefix(id, base+"-") {
			if len(base) > len(best) {
				best, bestName = base, name
			}
		}
	}
	if best == "" {
		return ""
	}
	return bestName + id[len(best):]
}

// writeDisplayName emits the config name: + a routable alias for a renamed served
// id (both = the advertised public name). The real served id stays the config
// key, so it still resolves; the alias makes the public name resolve too. No-op
// when the model wasn't renamed. Indent matches the 4-space model-field block.
func writeDisplayName(b *strings.Builder, s Settings, id string) {
	pub := resolvePublicName(s.DisplayNames, id)
	if pub == "" || pub == id {
		return
	}
	fmt.Fprintf(b, "    name: %q\n", pub)
	fmt.Fprintf(b, "    aliases: [%q]\n", pub)
}

func emitProfile(b *strings.Builder, s Settings, meta Metadata, row GgufRow, prof profile, ctx, ngl, ncpuMoe int, plan LoadPlan, kvK, kvV string, kvInRam bool, ov *Override) {
	fmt.Fprintf(b, "\n  # arch=%s size=%gGB blocks=%d moe=%v\n", meta.Architecture, meta.FileSizeGB, meta.BlockCount, meta.IsMoE)
	fmt.Fprintf(b, "  # est vram=%gGB ram=%gGB\n", plan.EstVramGB, plan.EstRamGB)
	fmt.Fprintf(b, "  %q:\n", prof.Name)
	// The user's custom launch arguments are the last layer of the emitted
	// command: a knob the text sets drops the generated flags for that knob. A
	// parse error cannot fail generation (this function has no error path), so
	// ComposeCmd leaves the text appended and the spawn reports the problem.
	composed, _ := ComposeCmd(buildCmdLines(s, meta, row, prof, ctx, ngl, ncpuMoe, kvK, kvV, kvInRam, ov), ov.CustomArgsText())
	b.WriteString("    cmd: >\n")
	for _, line := range composed.Lines {
		fmt.Fprintf(b, "      %s\n", line)
	}
	fmt.Fprintf(b, "    ttl: %d\n", s.TtlSec)
	// A split is expressed in TELEMETRY device order (nvidia-smi / DXGI), but the
	// CUDA runtime enumerates FASTEST_FIRST by default, so on a mismatched pair
	// the two orders disagree and the ratio lands on the wrong cards - silently,
	// with no error and a model that OOMs the small one. Pinning bus order makes
	// the ordinal mean one thing everywhere. Ignored by a Vulkan/ROCm build.
	if len(prof.TensorSplit) > 1 {
		fmt.Fprintf(b, "    env:\n      - %q\n", cudaOrderEnv)
	}
	writeEstVram(b, plan.EstVramGB)
	writeEstRam(b, plan.EstRamGB)
	writeDisplayName(b, s, prof.Name)
	if prof.Unlisted {
		b.WriteString("    unlisted: true\n")
	}
	// Per-model preamble opt-out, read by the server's slot cache. Only meaningful
	// for a model that actually persists (it got --slot-save-path above), and only
	// the off case is emitted - absent means on.
	if ov != nil && ov.SlotCachePreamble != nil && !*ov.SlotCachePreamble &&
		s.SlotCache.Enable && ov.SlotCache != nil && *ov.SlotCache {
		b.WriteString("    slotCachePreamble: false\n")
	}
	effort := effortLevels(meta, ov)
	if prof.Vision || len(effort) > 0 {
		b.WriteString("    capabilities:\n")
		if prof.Vision {
			b.WriteString("      in: [text, image]\n")
			b.WriteString("      out: [text]\n")
		}
		if len(effort) > 0 {
			fmt.Fprintf(b, "      reasoningEffort: [%s]\n", strings.Join(effort, ", "))
		}
	}
}

// effortLevels reports the reasoning-effort ladder to advertise for a model:
// the values the template ACTUALLY BEING RUN accepts. A --chat-template-file
// override replaces the baked template wholesale, so the gguf's ladder says
// nothing about the live renderer — advertising it there would have the server
// translate a client's reasoning_effort into a kwarg the live template ignores.
// The override file is therefore scanned in the gguf template's place: drop-in
// templates are where effort support most often lives (llama.cpp ships no way
// to ask the running server what kwargs its template reads), and the two Qwen
// 3.8 templates in circulation both support the ladder while only one of them
// declares it in a guard. An unreadable file advertises nothing, as before.
//
// With no override set the model runs its own baked template, so whatever the
// gguf declared is what it accepts.
func effortLevels(meta Metadata, ov *Override) []string {
	if ov != nil && strings.TrimSpace(ov.ChatTemplateFile) != "" {
		return chatTemplateFileEffortLevels(strings.TrimSpace(ov.ChatTemplateFile))
	}
	return meta.ChatTemplateEffortLevels
}

// chatTemplateFileEffortLevels reads a drop-in .jinja template and pulls its
// ladder out with the same scanner used on baked gguf templates. Results are
// memoized: one template file is typically shared by every ctx variant of every
// model that uses it, and this runs inside config generation.
var chatTemplateEffortCache sync.Map // abs path -> []string

func chatTemplateFileEffortLevels(path string) []string {
	key := path
	if abs, err := filepath.Abs(path); err == nil {
		key = abs
	}
	if v, ok := chatTemplateEffortCache.Load(key); ok {
		return v.([]string)
	}
	var levels []string
	if b, err := os.ReadFile(path); err == nil {
		_, levels = scanChatTemplate(string(b))
	}
	chatTemplateEffortCache.Store(key, levels)
	return levels
}

func formatCtxTag(ctx int) string {
	if ctx >= 1048576 && ctx%1048576 == 0 {
		return fmt.Sprintf("%dm", ctx/1048576)
	}
	if ctx >= 1024 && ctx%1024 == 0 {
		return fmt.Sprintf("%dk", ctx/1024)
	}
	return fmt.Sprintf("%d", ctx)
}

// slugify lowercases and collapses non-alphanumerics to single dashes.
func slugify(s string) string {
	var b strings.Builder
	prevDash := false
	for _, r := range strings.ToLower(s) {
		if (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') {
			b.WriteRune(r)
			prevDash = false
		} else if !prevDash {
			b.WriteByte('-')
			prevDash = true
		}
	}
	return strings.Trim(b.String(), "-")
}

// DefaultNow returns an RFC3339 timestamp for the generation header. Kept
// separate so Generate stays deterministic in tests.
func DefaultNow() string {
	return time.Now().Format(time.RFC3339)
}