import type { TimelineRange } from "@/uhm/lib/editor/session/sessionTypes";

// Single source of truth for the app-wide timeline range.
export const FIXED_TIMELINE_START_YEAR = -2000;
export const FIXED_TIMELINE_END_YEAR = 2000;

export const FIXED_TIMELINE_RANGE: TimelineRange = {
    min: FIXED_TIMELINE_START_YEAR,
    max: FIXED_TIMELINE_END_YEAR,
};

// UI debounce when user drags timeline before triggering data fetch.
export const TIMELINE_DEBOUNCE_MS = 180;

export function clampYearValue(year: number, minYear: number, maxYear: number): number {
    const lower = Math.min(minYear, maxYear);
    const upper = Math.max(minYear, maxYear);
    if (year < lower) return lower;
    if (year > upper) return upper;
    return year;
}

export function clampYearToFixedRange(year: number): number {
    return clampYearValue(year, FIXED_TIMELINE_START_YEAR, FIXED_TIMELINE_END_YEAR);
}

export function normalizeTimelineYearValue(value: unknown): number | null {
    if (typeof value === "number") {
        return Number.isFinite(value) ? Math.trunc(value) : null;
    }

    if (typeof value === "string") {
        const trimmed = value.trim();
        if (!trimmed.length) return null;
        const parsed = Number(trimmed);
        return Number.isFinite(parsed) ? Math.trunc(parsed) : null;
    }

    return null;
}