// ─────────────────────────────────────────────────────────────────────────────
// services/sessionState.ts – Active preset session management + overrides
// ─────────────────────────────────────────────────────────────────────────────
import deepmerge from "deepmerge";
import type { SessionState, Preset, DesignTokens } from "../types/index.js";
// ── Singleton state ───────────────────────────────────────────────────────────
let state: SessionState = {
activePresetId: null,
activePreset: null,
loadedAt: null,
overrides: {},
};
// ── Accessors ─────────────────────────────────────────────────────────────────
export function getSessionState(): SessionState {
return state;
}
export function getActivePreset(): Preset | null {
return state.activePreset;
}
export function getActivePresetId(): string | null {
return state.activePresetId;
}
export function requireActivePreset(toolName: string): Preset {
if (!state.activePreset) {
throw new Error(
`No active preset. Run load_preset first before calling ${toolName}.`
);
}
return state.activePreset;
}
export function getEffectiveTokens(): DesignTokens {
const preset = requireActivePreset("getEffectiveTokens");
if (Object.keys(state.overrides).length === 0) {
return preset.tokens;
}
return deepmerge(preset.tokens, state.overrides as DesignTokens, {
arrayMerge: (_dst, src) => src,
});
}
// ── Mutators ──────────────────────────────────────────────────────────────────
export function setActivePreset(presetId: string, preset: Preset): void {
state = {
activePresetId: presetId,
activePreset: preset,
loadedAt: new Date(),
overrides: {},
};
}
export function applyTokenOverrides(overrides: Partial<DesignTokens>): void {
state = {
...state,
overrides: deepmerge(state.overrides as DesignTokens, overrides as DesignTokens, {
arrayMerge: (_dst, src) => src,
}),
};
}
export function resetSession(): void {
state = {
activePresetId: null,
activePreset: null,
loadedAt: null,
overrides: {},
};
}
