/**
 * The saved parameters for a node type, as one list: material blocks
 * (GET /anomalous/materials/by_node_type) and recipes' parameter sets
 * (GET /anomalous/parameters/by_node_type), with the same values saved twice merged into
 * one entry that names both sources, each saying where it came from (a recipe's set with its
 * file and values' signature, a kept picture, or values saved in Current node). For a live
 * node, what an entry would change: every differing value, except seeds and how they change
 * after a run, model files (the model section changes those) and choices this computer does
 * not have, which stay. And the recent pictures made with each set's values. What was last
 * put into a node is remembered in this browser (per workflow and node), so the panel can say
 * which set the values came from and what changed since; without a record, which set the
 * values match or come closest to. No DOM.
 */

import { applyNodeMaterialValues, isModelFilePath, isVolatileWidget } from './node_material_actions.js';
import { workflowKey } from './canvas_undo.js';

const same = (a, b) => JSON.stringify(a) === JSON.stringify(b);
const APPLIED_KEY = 'anomalous_applied_sets'; // { "workflow|graph|node": record }, this browser only
const APPLIED_KEPT = 100; // records kept, the newest

async function fetchJson(url, signal) {
    const response = await fetch(url, { cache: 'no-store', signal });
    if (!response.ok) throw new Error(`HTTP ${response.status}`);
    return response.json();
}

/**
 * [{ name, role, timestamp, values, sources }], newest first. A source is a material
 * { kind: 'material', label, filename, timestamp, origin, image, preview } (origin: how it was
 * saved, 'generated_image' or 'canvas_node'; image: the kept picture { filename, subfolder } or
 * null; preview: its saved preview's URL or '') or a recipe set { kind: 'recipe', label (the
 * recipe), recipeFile, setFile, setName, timestamp, signature }.
 */
export async function loadParameterSets(type, { signal } = {}) {
    const query = `type=${encodeURIComponent(type)}`;
    const [materials, recipes] = await Promise.all([
        fetchJson(`/anomalous/materials/by_node_type?${query}`, signal),
        fetchJson(`/anomalous/parameters/by_node_type?${query}`, signal),
    ]);
    const entries = new Map();
    const add = (values, entry) => {
        if (!Array.isArray(values) || !values.length) return;
        const key = JSON.stringify(values);
        const known = entries.get(key);
        if (!known) entries.set(key, { ...entry, values });
        else {
            known.sources.push(...entry.sources);
            known.timestamp = Math.max(known.timestamp, entry.timestamp);
        }
    };
    for (const material of materials.materials || []) {
        const blocks = material.blocks || [];
        for (const block of blocks) {
            add(block.widgets_values, {
                name: blocks.length > 1 ? `${material.name} · ${block.title || block.type}` : material.name,
                role: block.role || '',
                timestamp: material.timestamp || 0,
                sources: [{
                    kind: 'material', label: material.name, filename: material.filename, timestamp: material.timestamp || 0,
                    origin: material.origin || '', image: material.source_image?.filename ? material.source_image : null,
                    preview: material.preview ? `/anomalous/material_asset?${new URLSearchParams({ filename: material.filename, asset: material.preview })}` : '',
                }],
            });
        }
    }
    for (const group of recipes.groups || []) {
        const recipe = String(group.recipe_name || group.recipe_filename || '');
        // Sets not bound to a recipe, or whose recipe is gone (only its file name is left).
        if (group.recipe_filename === 'unbound' || recipe.endsWith('.json')) continue;
        for (const notebook of group.notebooks || []) {
            const nodes = notebook.nodes || [];
            for (const node of nodes) {
                add(node.widgets_values, {
                    name: nodes.length > 1 ? `${notebook.name} · ${node.title}` : notebook.name,
                    role: node.role || '',
                    timestamp: notebook.timestamp || 0,
                    sources: [{
                        kind: 'recipe', label: recipe, recipeFile: group.recipe_filename, setFile: notebook.filename || '',
                        setName: notebook.name || '', timestamp: notebook.timestamp || 0, signature: notebook.signature || '',
                    }],
                });
            }
        }
    }
    return [...entries.values()].sort((a, b) => b.timestamp - a.timestamp);
}

/**
 * Every value of `values` for `node`: [{ index, label, from, to, status }], status being
 * 'change' (put in), 'same', or why the value stays: 'seed' | 'model' | 'missing'. Values of
 * another type than the node's input there are left out.
 */
export function parameterRows(node, values) {
    const rows = [];
    values.forEach((to, index) => {
        const widget = node.widgets?.[index];
        if (!widget || to === undefined || to === null) return;
        if (widget.value != null && typeof widget.value !== typeof to) return; // not the same input
        const label = widget.label || widget.name || `#${index}`;
        if (same(widget.value, to)) {
            rows.push({ index, label, from: widget.value, to, status: 'same' });
            return;
        }
        const choices = Array.isArray(widget.options?.values) ? widget.options.values : null;
        const status = isVolatileWidget(node, widget, index) || widget.name === 'control_after_generate' ? 'seed'
            : isModelFilePath(to) || isModelFilePath(widget.value) ? 'model'
                : choices && !choices.includes(to) ? 'missing' : 'change';
        rows.push({ index, label, from: widget.value, to, status });
    });
    return rows;
}

/**
 * What putting `values` into `node` would change: [{ index, label, from, to, keep }], keep
 * being '' for a change that is made, or why the value stays: 'seed' | 'model' | 'missing'.
 */
export function parameterChanges(node, values) {
    return parameterRows(node, values).filter(row => row.status !== 'same')
        .map(({ index, label, from, to, status }) => ({ index, label, from, to, keep: status === 'change' ? '' : status }));
}

/**
 * The recent pictures made with the recipe sets' values among `entries` (one pass over the
 * outputs): { signature: { count, newest: { filename, subfolder } } }; {} when none or unreadable.
 */
export async function loadSetPictures(entries, { signal } = {}) {
    const signatures = [...new Set(entries.flatMap(entry => entry.sources.map(source => source.signature)).filter(Boolean))].slice(0, 64);
    if (!signatures.length) return {};
    try {
        const data = await fetchJson(`/anomalous/parameter_pictures?signatures=${signatures.join(',')}`, signal);
        return data.pictures || {};
    } catch {
        return {};
    }
}

/** Puts the changes that are made into the node; the undoable result of node_material_actions. */
export function applyParameterChanges(app, node, changes) {
    return applyNodeMaterialValues(app, node, changes.filter(change => !change.keep).map(({ index, to }) => ({ index, value: to })));
}

function appliedStore() {
    try {
        const data = JSON.parse(globalThis.localStorage?.getItem(APPLIED_KEY) || '{}');
        return data && typeof data === 'object' && !Array.isArray(data) ? data : {};
    } catch {
        return {};
    }
}

function keepAppliedStore(store) {
    const newest = Object.entries(store).sort((a, b) => (b[1]?.at || 0) - (a[1]?.at || 0)).slice(0, APPLIED_KEPT);
    try {
        globalThis.localStorage?.setItem(APPLIED_KEY, JSON.stringify(Object.fromEntries(newest)));
    } catch { /* only a convenience: without storage the panel says which set the values match */ }
}

const appliedKey = (app, node) => `${workflowKey(app)}|${node.graph?.id || ''}|${node.id}`;

/**
 * Remembers that `entry`'s values were put into `node` (`rows`: its parameterRows before):
 * { name, at, values: { index: value } (the values it set or that were equal already), labels,
 * made: [index] (the ones it changed) }. Returns the record it replaces (null for none).
 */
export function rememberApplied(app, node, entry, rows, now = Date.now()) {
    const store = appliedStore();
    const key = appliedKey(app, node);
    const previous = store[key] || null;
    const held = rows.filter(row => row.status === 'change' || row.status === 'same');
    store[key] = {
        name: entry.name,
        at: now,
        values: Object.fromEntries(held.map(row => [row.index, row.to])),
        labels: Object.fromEntries(held.map(row => [row.index, row.label])),
        made: rows.filter(row => row.status === 'change').map(row => row.index),
    };
    keepAppliedStore(store);
    return previous;
}

/** Puts back the record rememberApplied replaced (null: none), when the change is undone. */
export function restoreApplied(app, node, previous) {
    const store = appliedStore();
    const key = appliedKey(app, node);
    if (previous) store[key] = previous;
    else delete store[key];
    keepAppliedStore(store);
}

/**
 * The node against what was last put into it: { record, changed: [{ index, label, from (the
 * set's), to (now) }] }, or null without a record or once none of the values it changed is
 * there any more (undone, or replaced since).
 */
export function appliedState(app, node) {
    const record = appliedStore()[appliedKey(app, node)];
    if (!record?.values) return null;
    const now = index => node.widgets?.[Number(index)]?.value;
    if (!(record.made || []).some(index => same(now(index), record.values[index]))) return null;
    const changed = Object.entries(record.values).filter(([index, value]) => !same(now(index), value))
        .map(([index, value]) => ({ index: Number(index), label: record.labels?.[index] || `#${index}`, from: value, to: now(index) }));
    return { record, changed };
}

/** Whether `entry` is the set `record` was taken from (its name, and every value it set). */
export function isAppliedEntry(entry, record) {
    return Boolean(record) && entry.name === record.name
        && Object.entries(record.values || {}).every(([index, value]) => same(entry.values[Number(index)], value));
}

/**
 * The saved set the node's values are now (none of its values would change anything), else the
 * one that would change the fewest, at most `most`: { entry, changes (parameterRows), others
 * (how many more match) }, or null.
 */
export function closestSet(node, entries, most = 3) {
    let best = null;
    let matches = 0;
    for (const entry of entries) {
        const rows = parameterRows(node, entry.values);
        if (!rows.some(row => row.status === 'same')) continue; // nothing in common to speak of
        const changes = rows.filter(row => row.status === 'change');
        if (!changes.length) matches += 1;
        if (!best || changes.length < best.changes.length) best = { entry, changes };
    }
    if (!best || best.changes.length > most) return null;
    return { ...best, others: best.changes.length ? 0 : matches - 1 };
}

/** Saves the node's current values as a material; { status: 'success' | 'duplicate', name }. */
/** Deletes saved values (a material file, with any other nodes saved with them) to the Recycle Bin. */
export async function deleteSavedValues(filename) {
    const response = await fetch('/anomalous/delete_material', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ filename }),
    });
    if (!response.ok) throw new Error(`HTTP ${response.status}`);
}

export async function saveNodeParameters(node, name) {
    const values = node.serialize?.().widgets_values || node.widgets_values || (node.widgets || []).map(widget => widget.value);
    const response = await fetch('/anomalous/save_node_material', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ name, node: { type: node.type, title: node.title || node.type, widgets_values: values } }),
    });
    const payload = await response.json().catch(() => ({}));
    if (payload.status === 'success') return { status: 'success', name: payload.material?.name || name };
    if (payload.status === 'duplicate') return { status: 'duplicate', name: payload.name };
    throw new Error(payload.message || `HTTP ${response.status}`);
}