import * as React from "react"
import { Circle, Minus, Triangle } from "lucide-react"

import { cn } from "../../lib/utils"
import { statusLabel, statusTone, type StatusTone } from "../../utils/fhirStatusVocabulary"
import { Badge } from "./badge"

// ------------------------------------------------------------------------------------------------
// / design decision D5 - a FHIR status, said once, in the product's voice, and encoded TWICE.
// ------------------------------------------------------------------------------------------------
// THE SHAPE IS NOT DECORATION. D5: *"Colour alone fails for ~8% of men and this is a clinical
// product."* A red dot and a green dot are the same dot to a deuteranopic reader, so every tone carries a
// distinct SILHOUETTE as well as a distinct colour - filled circle - triangle - hollow ring - bar. Remove
// the shape and this component stops doing the only thing it was built for.
//
// THE WORDS AND THE TONE BOTH COME FROM THE SHARED VOCABULARY, never from the caller. A surface that
// passes its own label is how the product ends up with three words for one state - the exact failure card
// 248 was raised about. `utils/fhirStatusVocabulary.ts`
//
// IT RENDERS NOTHING FOR A CODE WE HAVE NO WORDS FOR. `statusLabel` returns `undefined` there, and an
// unmapped code must not reach a patient wearing the shape of a deliberate label - that is the original
// defect (`Encounter [finished]`) arriving back through a fallback. Returning `null` makes the omission
// the caller's problem at the call site, where it can be seen, rather than a silent bad label on screen.
// - do not dress up "we don't know" as an answer.
//
// DO NOT add a `variant` or a `color` prop. The tone is derived from the status precisely so two
// surfaces cannot disagree about how serious the same state is.
// ------------------------------------------------------------------------------------------------

const TONE_PRESENTATION: Readonly<Record<StatusTone, { className: string; Icon: typeof Circle; fill: boolean }>> = {
    // Blue, the same role the product already uses for "this is live and normal" - not green, which would
    // read as an outcome on a thing that has not finished.
    live: { className: "text-primary", Icon: Circle, fill: true },
    // amber-700 (`--warning`), chosen in index.css for its 5.02:1 contrast rather than its brightness.
    attention: { className: "text-warning", Icon: Triangle, fill: true },
    // Deliberately MUTED. A visit that completed normally is the unremarkable case; drawing it as
    // loudly as a cancellation is how the statuses that matter stop being noticed.
    done: { className: "text-muted-foreground", Icon: Circle, fill: false },
    cancelled: { className: "text-destructive", Icon: Minus, fill: false },
}

export interface StatusProps extends Omit<React.ComponentProps<"span">, "children"> {
    /** The RAW FHIR status code - `in-progress`, `entered-in-error`. Never a pre-formatted label. */
    status: string | undefined
    /**
 * Hides the shape, leaving the word alone. For dense rows where the icon is noise - NOT a way to opt
 * out of D5 on a surface where the status carries weight, because the word alone is the thing that
 * fails for a colour-blind reader once anything else on the row is colour-coded.
 */
    hideIcon?: boolean
}

function Status({ status, hideIcon = false, className, ...props }: StatusProps) {
    const label = statusLabel(status)
    // No words for it render nothing at all. See the header: a fallback here would reintroduce the bug.
    if (!label) return null

    const tone = statusTone(status)
    const presentation = tone ? TONE_PRESENTATION[tone] : undefined

    return (
        <span
            data-slot="status"
            data-tone={tone ?? "none"}
            className={cn("inline-flex items-center gap-1.5 whitespace-nowrap", presentation?.className, className)}
            {...props}
        >
            {presentation && !hideIcon && (
                <presentation.Icon
                    // `aria-hidden` because the LABEL beside it already carries the meaning to a screen
                    // reader. The shape exists for sighted readers who cannot rely on the colour; adding a
                    // second announcement would make every status read twice.
                    aria-hidden="true"
                    // Sized by class, never inline. `size-3` matches the
                    // icon size Badge already uses, so a Status inside a Badge does not jump.
                    className={cn("size-3 shrink-0", presentation.fill && "fill-current")}
                />
            )}
            {label}
        </span>
    )
}

/**
 * A `Status` in a neutral chip - the shape the FHIR detail sheets were already using, minus the twelve
 * hand-rolled colour maps.
 *
 * WHAT IT REPLACES: each `Fhir*Display` carried its OWN `STATUS_STYLES` record of hardcoded hex pairs
 * (`{ bg: "#DCFCE7", text: "#116932" }`), applied as an INLINE STYLE, encoding the status in colour alone
 * and printing the raw code as the text. Twelve copies, twelve chances to disagree, none of them reading
 * from a token and none of them survivable by a colour-blind reader.
 *
 * The chip itself is deliberately NEUTRAL now: `Status` carries the colour and the shape, so a coloured
 * background would be a third encoding of the same fact competing with the two D5 asked for.
 *
 * Renders `null` when the status is absent or unmapped, so a caller cannot end up with an empty chip.
 */
function StatusBadge({ status, className, ...props }: StatusProps) {
    if (!statusLabel(status)) return null

    return (
        <Badge variant="outline" className={cn("px-3 py-1 text-xs font-normal", className)}>
            <Status status={status} {...props} />
        </Badge>
    )
}

export { Status, StatusBadge, TONE_PRESENTATION }