package catalogue

import (
	"fmt"
	"strings"
)

// The graphical session's seats (novox/hq ADR 0208): one module per piece of software, each piece's
// role a node seat in the mesh's own set, so i3 and sway, xterm and foot, rofi and dmenu compete for
// a role rather than each inventing one — and a machine running two of one role is refused at
// assignment instead of found by two bars on one screen.
const (
	LoginManagerSeat     = "node-login-manager"
	DisplayServerSeat    = "node-display-server"
	DisplaySessionSeat   = "node-display-session"
	TerminalEmulatorSeat = "node-terminal-emulator"
	LauncherSeat         = "node-launcher"
	NotifierSeat         = "node-notifier"
	LockScreenSeat       = "node-lock-screen"
	ClipboardSeat        = "node-clipboard"
	BarSeat              = "node-bar"
	CompositorSeat       = "node-compositor"
	SecretServiceSeat    = "node-secret-service"
)

// graphicalSessionSeats are the eleven, in the order ADR 0208's table reads, each with the verbs
// research 026/05 starts it with. Three have none yet: the bar (which receives blocks instead,
// ADR 0255), the compositor and the secret
// service are roles a second holder competes for, and nothing has needed to ask them anything.
func graphicalSessionSeats() []Seat {
	const decided = "novox/hq ADR 0208"
	return []Seat{
		{Name: LoginManagerSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "sessions", Description: "The sessions the login manager offers on this machine, and which " +
				"one the operator account starts by default.",
				Input: schema(map[string]string{}, nil)},
		}},
		{Name: DisplayServerSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "displays", Description: "The monitors connected now, each with its identity, its modes and " +
				"where it is placed; and the layout profile in force, if one matches.",
				Input: schema(map[string]string{}, nil)},
			// Profiles are keyed by the monitors' identities and are the operator's data (ADR 0208 §6).
			{Name: "layout", Description: "The monitor layout profiles, keyed by the connected monitors' " +
				"identities: list them, save the current arrangement under a name, or apply one.",
				Input: withEnum(schema(map[string]string{
					"action": "list, save or apply",
					"name":   "the profile to save or apply (save and apply only)",
				}, []string{"action"}), "action", "list", "save", "apply")},
		}},
		// It receives window-manager configuration lines from every other module (novox/hq ADR 0212):
		// bindings, start-up commands, rules — placed by the session's holder, never written into
		// its directory by the contributor.
		{Name: DisplaySessionSeat, Scope: ScopeNode, Decision: decided,
			Receives: []Receivable{{Kind: "config", Comment: "#"}}, Serves: []Verb{
				{Name: "reload", Description: "Reload the session's configuration in place, keeping its windows.",
					Input: schema(map[string]string{}, nil)},
				{Name: "workspaces", Description: "The session's workspaces: each one's name, output, and whether " +
					"it is visible or focused.",
					Input: schema(map[string]string{}, nil)},
				{Name: "windows", Description: "The session's windows: each one's title, class, workspace and " +
					"whether it has focus; narrowed to one workspace when named.",
					Input: schema(map[string]string{"workspace": "one workspace (optional)"}, nil)},
			}},
		{Name: TerminalEmulatorSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "open", Description: "Open a terminal window in the operator's session, running a command " +
				"or the login shell, in a directory or the account's home.",
				Input: schema(map[string]string{
					"command":   "what to run in it (optional; the login shell when absent)",
					"directory": "where it starts (optional; the account's home when absent)",
				}, nil)},
		}},
		{Name: LauncherSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "menu", Description: "Put a menu of choices in front of the operator and answer with the " +
				"one chosen, or nothing when the menu was dismissed — the dmenu-compatible contract.",
				Input: map[string]any{"type": "object", "required": []string{"choices"},
					"properties": map[string]any{
						"choices": map[string]any{"type": "array", "items": map[string]any{"type": "string"},
							"description": "the lines to choose between, in order"},
						"prompt": map[string]any{"type": "string", "description": "what the menu asks (optional)"},
					}}},
		}},
		{Name: NotifierSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "send", Description: "Show the operator a notification.",
				Input: withEnum(schema(map[string]string{
					"title":   "the notification's summary",
					"body":    "its text (optional)",
					"urgency": "low, normal (the default) or critical",
				}, []string{"title"}), "urgency", "low", "normal", "critical")},
			{Name: "history", Description: "The notifications shown lately, newest first.",
				Input: schema(map[string]string{"limit": "how many (optional, default 20)"}, nil)},
		}},
		{Name: LockScreenSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "lock", Description: "Lock the operator's session now.",
				Input: schema(map[string]string{}, nil)},
		}},
		{Name: ClipboardSeat, Scope: ScopeNode, Decision: decided, Serves: []Verb{
			{Name: "history", Description: "What the clipboard held lately, newest first.",
				Input: schema(map[string]string{"limit": "how many (optional, default 20)"}, nil)},
			{Name: "copy", Description: "Put text on the operator's clipboard.",
				Input: schema(map[string]string{"text": "the text"}, []string{"text"})},
		}},
		// It receives blocks as data (novox/hq ADR 0255): what a block shows, said for any bar, which
		// the holder renders in its own grammar. A module that knows something about the machine — the
		// power module its battery — gives the block; the bar knows no machine's hardware.
		{Name: BarSeat, Scope: ScopeNode, Decision: decided,
			Receives: []Receivable{{Kind: BarKindBlock, Comment: "#", Offered: true, Shape: barBlockShape()}}},
		{Name: CompositorSeat, Scope: ScopeNode, Decision: decided},
		{Name: SecretServiceSeat, Scope: ScopeNode, Decision: decided},
	}
}

// withEnum narrows one string property of a schema to the values it may take, so a caller is told
// the choices by the schema rather than by a refusal.
func withEnum(s map[string]any, property string, values ...string) map[string]any {
	props := s["properties"].(map[string]any)
	p := props[property].(map[string]any)
	p["enum"] = values
	return s
}

// BarKindBlock is the bar's one received kind: a block (novox/hq ADR 0255).
const BarKindBlock = "block"

// barShows is what a contributed block may show, and the options each takes — the bar-neutral
// vocabulary every holder of node-bar renders. A new entry is a decision, and every holder's template
// renders it (the shape's examples) before it is accepted.
var barShows = map[string]map[string]barOption{
	// The machine's battery: its charge, and how long it lasts or takes to fill.
	"battery": {"device": {kind: "text"}},
	// One line a command prints, run every interval seconds: what the bar cannot know itself.
	"command": {"command": {kind: "text", required: true}, "interval": {kind: "seconds", required: true}},
	// A value the contributor keeps on the bus (novox/hq ADR 0255): its state `<module>.<name>` and the
	// key, this machine's name when absent. The value is an object whose `text` is what is shown. The
	// holder is granted to read it and shows it however its bar shows a changing value; no file and
	// no command passes between the two modules.
	"state": {"state": {kind: "text", required: true}, "key": {kind: "text"}},
}

// barBlockReads is the state a block shows, if any.
func barBlockReads(data map[string]any) []string {
	if data["shows"] != "state" {
		return nil
	}
	options, _ := data["options"].(map[string]any)
	if s, ok := options["state"].(string); ok && s != "" {
		return []string{s}
	}
	return nil
}

type barOption struct {
	kind     string // text, or seconds (a whole number from 1 to 86400)
	required bool
}

// barBlockShape is the shape of a block (novox/hq ADR 0255): which bar, where on it, in what order,
// what it shows, and that kind's options.
//
//   - bar: top or bottom;
//   - place: resources (beside the processor, memory and disks) or status (beside the sound, before the
//     clock) — the two places every holder keeps for contributed blocks;
//   - order: 0–99 within the place, 50 when absent;
//   - shows: battery or command; options: what that kind takes.
func barBlockShape() *Shape {
	return &Shape{
		Places: []PlaceField{{Field: "bar", Values: []string{"bottom", "top"}},
			{Field: "place", Values: []string{"resources", "status"}}},
		Order: "order",
		Check: barBlockProblems,
		Reads: barBlockReads,
		Examples: []map[string]any{
			{"bar": "bottom", "place": "status", "shows": "battery"},
			{"bar": "bottom", "place": "status", "shows": "battery", "options": map[string]any{"device": "BAT0"}},
			{"bar": "bottom", "place": "status", "shows": "command",
				"options": map[string]any{"command": "echo \"a line\"", "interval": float64(5)}},
			{"bar": "bottom", "place": "status", "shows": "state", "options": map[string]any{"state": "power.draw"}},
			{"bar": "bottom", "place": "status", "shows": "state",
				"options": map[string]any{"state": "power.draw", "key": "a-machine"}},
		},
	}
}

func barBlockProblems(data map[string]any) []string {
	var problems []string
	for field := range data {
		if !oneOf([]string{"bar", "place", "order", "shows", "options"}, field) {
			problems = append(problems, fmt.Sprintf("a block has no field %q; it has bar, place, order, shows and options", field))
		}
	}
	shows, _ := data["shows"].(string)
	takes, known := barShows[shows]
	if !known {
		return append(problems, fmt.Sprintf("a block shows %v; it shows one of %s", data["shows"],
			strings.Join(sortedKeys(barShows), ", ")))
	}
	options := map[string]any{}
	if raw, has := data["options"]; has {
		o, ok := raw.(map[string]any)
		if !ok {
			return append(problems, "a block's options are an object")
		}
		options = o
	}
	for name, v := range options {
		opt, ok := takes[name]
		if !ok {
			problems = append(problems, fmt.Sprintf("a %s block has no option %q; it takes %s", shows, name,
				orNothing(sortedKeys(takes))))
			continue
		}
		switch opt.kind {
		case "text":
			if t, isText := v.(string); !isText || strings.TrimSpace(t) == "" {
				problems = append(problems, fmt.Sprintf("a %s block's %s is text", shows, name))
			}
		case "seconds":
			if _, whole := wholeIn(v, 1, 86400); !whole {
				problems = append(problems, fmt.Sprintf("a %s block's %s is a whole number of seconds from 1 to 86400", shows, name))
			}
		}
	}
	for _, name := range sortedKeys(takes) {
		if _, has := options[name]; takes[name].required && !has {
			problems = append(problems, fmt.Sprintf("a %s block needs the option %s", shows, name))
		}
	}
	return problems
}