import {
	type PipelineConfig,
	type PipelinePreset,
	DEFAULT_PIPELINE_CONFIG,
	BUILT_IN_PRESETS,
	clonePipelineConfig
} from '$lib/types';

const STORAGE_KEY = '2eink-pipeline-presets';

function createPipelineStore() {
	let globalConfig = $state<PipelineConfig>(clonePipelineConfig(DEFAULT_PIPELINE_CONFIG));
	let selectedPresetId = $state<string | null>('default');
	let userPresets = $state<PipelinePreset[]>([]);

	const allPresets = $derived<PipelinePreset[]>([...BUILT_IN_PRESETS, ...userPresets]);

	const selectedPreset = $derived<PipelinePreset | null>(
		allPresets.find((p) => p.id === selectedPresetId) ?? null
	);

	const isModified = $derived<boolean>(() => {
		if (!selectedPreset) return true;
		return JSON.stringify(globalConfig) !== JSON.stringify(selectedPreset.config);
	});

	function loadPresets(): void {
		if (typeof window === 'undefined') return;
		try {
			const stored = localStorage.getItem(STORAGE_KEY);
			if (stored) {
				userPresets = JSON.parse(stored);
			}
		} catch {
			console.warn('Failed to load pipeline presets');
		}
	}

	function savePresets(): void {
		if (typeof window === 'undefined') return;
		try {
			localStorage.setItem(STORAGE_KEY, JSON.stringify(userPresets));
		} catch {
			console.warn('Failed to save pipeline presets');
		}
	}

	function selectPreset(presetId: string): void {
		const preset = allPresets.find((p) => p.id === presetId);
		if (preset) {
			globalConfig = clonePipelineConfig(preset.config);
			selectedPresetId = presetId;
		}
	}

	function updateConfig(updates: Partial<PipelineConfig>): void {
		globalConfig = { ...globalConfig, ...updates };
	}

	function updateStep<K extends keyof PipelineConfig>(
		step: K,
		updates: Partial<PipelineConfig[K]>
	): void {
		globalConfig = {
			...globalConfig,
			[step]: { ...globalConfig[step], ...updates }
		};
	}

	function saveAsPreset(name: string): PipelinePreset {
		const id = `user-${Date.now()}`;
		const preset: PipelinePreset = {
			id,
			name,
			config: clonePipelineConfig(globalConfig),
			isBuiltIn: false
		};

		userPresets = [...userPresets, preset];
		selectedPresetId = id;
		savePresets();

		return preset;
	}

	function updatePreset(presetId: string): void {
		const index = userPresets.findIndex((p) => p.id === presetId);
		if (index === -1) return;

		userPresets = userPresets.map((p) =>
			p.id === presetId ? { ...p, config: clonePipelineConfig(globalConfig) } : p
		);
		savePresets();
	}

	function deletePreset(presetId: string): void {
		const preset = userPresets.find((p) => p.id === presetId);
		if (!preset || preset.isBuiltIn) return;

		userPresets = userPresets.filter((p) => p.id !== presetId);
		if (selectedPresetId === presetId) {
			selectPreset('default');
		}
		savePresets();
	}

	function renamePreset(presetId: string, newName: string): void {
		userPresets = userPresets.map((p) => (p.id === presetId ? { ...p, name: newName } : p));
		savePresets();
	}

	function resetToDefault(): void {
		selectPreset('default');
	}

	function getEffectiveConfig(imageOverride: PipelineConfig | null): PipelineConfig {
		return imageOverride ?? globalConfig;
	}

	if (typeof window !== 'undefined') {
		loadPresets();
	}

	return {
		get globalConfig() {
			return globalConfig;
		},
		get selectedPresetId() {
			return selectedPresetId;
		},
		get selectedPreset() {
			return selectedPreset;
		},
		get allPresets() {
			return allPresets;
		},
		get userPresets() {
			return userPresets;
		},
		get isModified() {
			return isModified;
		},
		selectPreset,
		updateConfig,
		updateStep,
		saveAsPreset,
		updatePreset,
		deletePreset,
		renamePreset,
		resetToDefault,
		getEffectiveConfig,
		loadPresets
	};
}

export const pipelineStore = createPipelineStore();