/**
 * Chi Commons configuration.
 *
 * The zod schema follows the chi-base settings-editor constraint: top-level
 * `z.enum` or `z.string` fields with defaults. Booleans are modeled as
 * "on"/"off" enums and numbers as strings; `parseCommonsConfig` converts the
 * stored shape into the typed `CommonsConfig` the module consumes (per
 * MVP_PLAN.md "Chi Base config consumed").
 */
import { z } from "zod";

export const commonsConfigSchema = z.object({
	enabled: z.enum(["on", "off"]).default("on"),
	autoReduce: z.enum(["on", "off"]).default("off"),
	reduceCadenceRounds: z.string().default("4"),
	generatedTitles: z.enum(["on", "off"]).default("on"),
	maxInsertTokens: z.string().default("2000"),
	requireRawInsertConfirmation: z.enum(["on", "off"]).default("on"),
	/** Comma-separated model preference for reduction; first available wins. */
	reduceModels: z.string().default("claude-sonnet-5,gpt-5.6-terra"),
});

export type StoredCommonsConfig = z.infer<typeof commonsConfigSchema>;

/** Typed runtime config consumed by chi-commons. */
export interface CommonsConfig {
	enabled: boolean;
	autoReduce: boolean;
	reduceCadenceRounds: number;
	generatedTitles: boolean;
	maxInsertTokens: number;
	requireRawInsertConfirmation: boolean;
	reduceModels: string[];
}

export const DEFAULT_COMMONS_CONFIG: CommonsConfig = {
	enabled: true,
	autoReduce: false,
	reduceCadenceRounds: 4,
	generatedTitles: true,
	maxInsertTokens: 2000,
	requireRawInsertConfirmation: true,
	reduceModels: ["claude-sonnet-5", "gpt-5.6-terra"],
};

function toPositiveInt(value: string, fallback: number): number {
	const parsed = Number.parseInt(value, 10);
	if (!Number.isFinite(parsed) || parsed <= 0) return fallback;
	return parsed;
}

/** Convert the stored (string/enum) shape into the typed runtime config. */
export function parseCommonsConfig(
	stored: Partial<StoredCommonsConfig> | undefined,
): CommonsConfig {
	const parsed = commonsConfigSchema.parse(stored ?? {});
	return {
		enabled: parsed.enabled === "on",
		autoReduce: parsed.autoReduce === "on",
		reduceCadenceRounds: toPositiveInt(
			parsed.reduceCadenceRounds,
			DEFAULT_COMMONS_CONFIG.reduceCadenceRounds,
		),
		generatedTitles: parsed.generatedTitles === "on",
		maxInsertTokens: toPositiveInt(
			parsed.maxInsertTokens,
			DEFAULT_COMMONS_CONFIG.maxInsertTokens,
		),
		requireRawInsertConfirmation: parsed.requireRawInsertConfirmation === "on",
		reduceModels: parsed.reduceModels.split(",").map((m) => m.trim()).filter(Boolean),
	};
}