import z from "zod";

/** Per-environment configuration block — narrow projection of Altair's. */
export interface AltairEnvironment {
    readonly url?: string;
    readonly subscriptionsEndpoint?: string;
    readonly headers?: Readonly<Record<string, string>>;
    readonly variables?: Readonly<Record<string, string>>;
}

const environmentSchema = z
    .object({
        url: z.string().optional(),
        subscriptionsEndpoint: z.string().optional(),
        headers: z.record(z.string(), z.string()).optional(),
        variables: z.record(z.string(), z.string()).optional(),
    })
    .strict();

/**
 * Zod schema for {@link AltairUiOptions}. The schema is intentionally
 * permissive on header/environment values — operators can plug arbitrary
 * string values into the embedded shell — and strict on the four
 * structural fields (endpoints + theme).
 */
export const altairUiOptionsSchema = z
    .object({
        uiEndpoint: z
            .string()
            .min(1)
            .startsWith("/", {
                message: "uiEndpoint must start with '/'",
            })
            .default("/graphql/ui"),
        graphqlEndpoint: z
            .string()
            .min(1)
            .startsWith("/", {
                message: "graphqlEndpoint must start with '/'",
            })
            .default("/graphql"),
        subscriptionEndpoint: z
            .string()
            .min(1)
            .startsWith("/", {
                message: "subscriptionEndpoint must start with '/'",
            })
            .default("/graphql/ws"),
        theme: z.enum(["light", "dark", "system"]).default("system"),
        initialQuery: z.string().default(""),
        initialHeaders: z.record(z.string(), z.string()).default({}),
        initialEnvironments: z
            .record(z.string(), environmentSchema)
            .default({}),
    })
    .strict();

/** Parsed, defaulted options consumed by `createAltairUi`. */
export type AltairUiOptions = z.infer<typeof altairUiOptionsSchema>;

/** Caller-facing input — every field optional, defaults applied by Zod. */
export type AltairUiOptionsInput = z.input<typeof altairUiOptionsSchema>;

/**
 * Validate caller-supplied options. Throws on shape violations; returns
 * a fully-defaulted, immutable `AltairUiOptions` on success.
 */
export function parseAltairUiOptions(
    input: AltairUiOptionsInput | undefined
): AltairUiOptions {
    return altairUiOptionsSchema.parse(input ?? {});
}