import { Window } from "happy-dom"
import type { Options } from "../src/morphlex"

type BenchmarkCase = {
	name: string
	from: string
	to: string
	iterations?: number
	weight?: number
	options?: Options
	setup?: (from: ChildNode, to: ChildNode) => void
}

type BenchmarkResult = {
	name: string
	iterations: number
	mean: number
	median: number
	p95: number
	min: number
	max: number
	opsPerSecond: number
	total: number
}

type CliOptions = {
	iterations: number
	warmup: number
	thorough: boolean
	json: boolean
	repeats: number
}

type BenchmarkSummary = {
	weightedMedianMs: number
	weightedP95Ms: number
	totalMeasuredMs: number
	trimmedMeanMs: number
}

const DEFAULT_ITERATIONS = 1500
const DEFAULT_WARMUP = 250

const window = new Window({
	url: "http://localhost",
})

Object.assign(window, {
	SyntaxError,
})

const globals: Record<string, unknown> = {
	window,
	document: window.document,
	Node: window.Node,
	Element: window.Element,
	NodeList: window.NodeList,
	DOMParser: window.DOMParser,
	DocumentFragment: window.DocumentFragment,
	HTMLInputElement: window.HTMLInputElement,
	HTMLOptionElement: window.HTMLOptionElement,
	HTMLTextAreaElement: window.HTMLTextAreaElement,
	performance: window.performance,
}

for (const [key, value] of Object.entries(globals)) {
	Object.assign(globalThis, { [key]: value })
}

const { morph } = await import("../src/morphlex")

const noopOptions: Options = {
	beforeNodeVisited: () => true,
	afterNodeVisited: () => {},
	beforeNodeAdded: () => true,
	afterNodeAdded: () => {},
	beforeNodeRemoved: () => true,
	afterNodeRemoved: () => {},
	beforeAttributeUpdated: () => true,
	afterAttributeUpdated: () => {},
	beforeChildrenVisited: () => true,
	afterChildrenVisited: () => {},
}

function buildIdRelatedCards(count: number, reverseOrder: boolean, updatedText: boolean): string {
	const indices = Array.from({ length: count }, (_, i) => i)
	if (reverseOrder) indices.reverse()

	return indices
		.map((i) => {
			const next = (i + 1) % count
			return `<article data-card="${i}"><h3 id="card-${i}">Card ${i}</h3><a href="#card-${next}" name="card-link-${i}">Next</a><p>${updatedText ? `Card ${i} updated` : `Card ${i}`}</p></article>`
		})
		.join("")
}

function buildPartiallyReorderedList(count: number, shift: number): string {
	const indices = Array.from({ length: count }, (_, i) => i)
	const rotated = indices.slice(shift).concat(indices.slice(0, shift))
	return rotated.map((i) => `<li id="row-${i}">Row ${i}</li>`).join("")
}

function buildDeepNestedIdTrees(count: number, depth: number, reverseOrder: boolean, updatedText: boolean): string {
	const indices = Array.from({ length: count }, (_, i) => i)
	if (reverseOrder) indices.reverse()

	return indices
		.map((i) => {
			const next = (i + 1) % count
			let nested = `<span id="deep-id-${i}">Node ${i}${updatedText ? " updated" : ""}</span><a href="#deep-id-${next}">Next</a>`
			for (let d = 0; d < depth; d++) {
				nested = `<div data-depth="${d}" data-key="${i}-${d}">${nested}</div>`
			}
			return `<article data-chain="${i}">${nested}</article>`
		})
		.join("")
}

const benchmarkCases: Array<BenchmarkCase> = [
	{
		name: "text-update",
		from: "<div>Hello world</div>",
		to: "<div>Goodbye world</div>",
		weight: 1,
	},
	{
		name: "attribute-churn",
		from: '<div class="a" data-mode="old" aria-hidden="true">Content</div>',
		to: '<div class="b" data-mode="new" title="fresh">Content</div>',
		weight: 1,
	},
	{
		name: "append-children",
		from: "<ul><li>One</li></ul>",
		to: "<ul><li>One</li><li>Two</li><li>Three</li><li>Four</li></ul>",
		weight: 1,
	},
	{
		name: "remove-children",
		from: "<ul><li>One</li><li>Two</li><li>Three</li><li>Four</li></ul>",
		to: "<ul><li>One</li></ul>",
		weight: 1,
	},
	{
		name: "reorder-with-ids-20",
		from: `<ul>${Array.from({ length: 20 }, (_, i) => `<li id="item-${i}">Item ${i}</li>`).join("")}</ul>`,
		to: `<ul>${Array.from({ length: 20 }, (_, i) => `<li id="item-${19 - i}">Item ${19 - i}</li>`).join("")}</ul>`,
		weight: 2,
	},
	{
		name: "large-list-update-200",
		from: `<div>${Array.from({ length: 200 }, (_, i) => `<p id="row-${i}">Row ${i}</p>`).join("")}</div>`,
		to: `<div>${Array.from({ length: 200 }, (_, i) => `<p id="row-${i}">Row ${i} updated</p>`).join("")}</div>`,
		iterations: 400,
		weight: 3,
	},
	{
		name: "mixed-structure",
		from: '<section><h1 id="title">Title</h1><p>Body</p><footer><a href="#">Link</a></footer></section>',
		to: '<section><h1 id="title">Title 2</h1><p>Body updated</p><aside>Side</aside><footer><a href="/x">Link</a></footer></section>',
		weight: 2,
	},
	{
		name: "partial-reorder-with-ids-100",
		from: `<ul>${buildPartiallyReorderedList(100, 0)}</ul>`,
		to: `<ul>${buildPartiallyReorderedList(100, 30)}</ul>`,
		iterations: 350,
		weight: 3,
	},
	{
		name: "idset-matching-related-cards-60",
		from: `<section>${buildIdRelatedCards(60, false, false)}</section>`,
		to: `<section>${buildIdRelatedCards(60, true, true)}</section>`,
		iterations: 350,
		weight: 3,
	},
	{
		name: "deep-id-ancestry-40x8",
		from: `<section>${buildDeepNestedIdTrees(40, 8, false, false)}</section>`,
		to: `<section>${buildDeepNestedIdTrees(40, 8, true, true)}</section>`,
		iterations: 300,
		weight: 3,
	},
	{
		name: "dirty-form-text-inputs-60",
		from: `<form>${Array.from({ length: 60 }, (_, i) => `<input name="field-${i}" value="value-${i}">`).join("")}</form>`,
		to: `<form>${Array.from({ length: 60 }, (_, i) => `<input name="field-${i}" value="new-${i}" data-next="1">`).join("")}</form>`,
		iterations: 500,
		weight: 1,
		setup: (from) => {
			const textInputs = (from as Element).querySelectorAll("input[name^='field-']")
			for (let i = 0; i < textInputs.length; i++) {
				const input = textInputs[i] as HTMLInputElement
				input.value = `${input.value}-dirty`
			}
		},
	},
	{
		name: "dirty-form-checkboxes-60",
		from: `<form>${Array.from({ length: 60 }, (_, i) => `<input type="checkbox" name="check-${i}" ${i % 3 === 0 ? "checked" : ""}>`).join("")}</form>`,
		to: `<form>${Array.from({ length: 60 }, (_, i) => `<input type="checkbox" name="check-${i}" ${i % 5 === 0 ? "checked" : ""}>`).join("")}</form>`,
		iterations: 500,
		weight: 1,
		setup: (from) => {
			const checkboxes = (from as Element).querySelectorAll("input[type='checkbox']")

			for (let i = 0; i < checkboxes.length; i++) {
				if (i % 4 === 0) {
					const checkbox = checkboxes[i] as HTMLInputElement
					checkbox.checked = !checkbox.checked
				}
			}
		},
	},
	{
		name: "hooks-mixed-structure",
		from: '<section><h1 id="title">Title</h1><p>Body</p><footer><a href="#">Link</a></footer></section>',
		to: '<section><h1 id="title">Title 2</h1><p>Body updated</p><aside>Side</aside><footer><a href="/x">Link</a></footer></section>',
		options: noopOptions,
		weight: 2,
	},
]

function parseOptions(argv: Array<string>): CliOptions {
	let iterations = DEFAULT_ITERATIONS
	let warmup = DEFAULT_WARMUP
	let thorough = false
	let json = false
	let repeats = 1

	for (let i = 0; i < argv.length; i++) {
		const arg = argv[i]
		if (arg === "--thorough") {
			thorough = true
			continue
		}

		if (arg === "--json") {
			json = true
			continue
		}

		if (arg === "--iterations") {
			const value = Number(argv[i + 1])
			if (Number.isFinite(value) && value > 0) {
				iterations = Math.floor(value)
				i++
			}
			continue
		}

		if (arg === "--warmup") {
			const value = Number(argv[i + 1])
			if (Number.isFinite(value) && value >= 0) {
				warmup = Math.floor(value)
				i++
			}
			continue
		}

		if (arg === "--repeats") {
			const value = Number(argv[i + 1])
			if (Number.isFinite(value) && value > 0) {
				repeats = Math.floor(value)
				i++
			}
		}
	}

	if (thorough) {
		iterations = Math.max(iterations, 5000)
		warmup = Math.max(warmup, 1000)
	}

	return { iterations, warmup, thorough, json, repeats }
}

function median(numbers: Array<number>): number {
	if (numbers.length === 0) return 0
	const sorted = [...numbers].sort((a, b) => a - b)
	return sorted[Math.floor(sorted.length / 2)] ?? 0
}

function createElement(html: string): ChildNode {
	const template = document.createElement("template")
	template.innerHTML = html
	const node = template.content.firstChild
	if (!node) throw new Error("Invalid benchmark fixture")
	return node
}

function runCase(testCase: BenchmarkCase, options: CliOptions): BenchmarkResult {
	const fromTemplate = createElement(testCase.from)
	const toTemplate = createElement(testCase.to)
	const iterations = testCase.iterations ?? options.iterations
	const times: Array<number> = []
	const morphOptions = testCase.options ?? {}

	for (let i = 0; i < options.warmup; i++) {
		const from = fromTemplate.cloneNode(true) as ChildNode
		const to = toTemplate.cloneNode(true) as ChildNode
		testCase.setup?.(from, to)
		morph(from, to, morphOptions)
	}

	for (let i = 0; i < iterations; i++) {
		const from = fromTemplate.cloneNode(true) as ChildNode
		const to = toTemplate.cloneNode(true) as ChildNode
		testCase.setup?.(from, to)
		const start = performance.now()
		morph(from, to, morphOptions)
		const end = performance.now()
		times.push(end - start)
	}

	times.sort((a, b) => a - b)
	let total = 0
	for (let i = 0; i < times.length; i++) total += times[i]!

	const mean = total / times.length
	const median = times[Math.floor(times.length / 2)] ?? 0
	const p95 = times[Math.floor(times.length * 0.95)] ?? 0
	const min = times[0] ?? 0
	const max = times[times.length - 1] ?? 0
	const opsPerSecond = mean > 0 ? 1000 / mean : 0

	return {
		name: testCase.name,
		iterations,
		mean,
		median,
		p95,
		min,
		max,
		opsPerSecond,
		total,
	}
}

function summarizeResults(results: Array<BenchmarkResult>): BenchmarkSummary {
	let totalWeight = 0
	let weightedMedianMs = 0
	let weightedP95Ms = 0
	let totalMeasuredMs = 0
	let weightedTrimmedMeanMs = 0

	for (let i = 0; i < results.length; i++) {
		const result = results[i]!
		const testCase = benchmarkCases[i]!
		const weight = testCase.weight ?? 1
		const trimmedMean = Math.min(result.p95, result.mean)

		totalWeight += weight
		weightedMedianMs += result.median * weight
		weightedP95Ms += result.p95 * weight
		weightedTrimmedMeanMs += trimmedMean * weight
		totalMeasuredMs += result.total
	}

	if (totalWeight === 0) {
		return {
			weightedMedianMs: 0,
			weightedP95Ms: 0,
			totalMeasuredMs,
			trimmedMeanMs: 0,
		}
	}

	return {
		weightedMedianMs: weightedMedianMs / totalWeight,
		weightedP95Ms: weightedP95Ms / totalWeight,
		totalMeasuredMs,
		trimmedMeanMs: weightedTrimmedMeanMs / totalWeight,
	}
}

function aggregateResults(runs: Array<Array<BenchmarkResult>>): Array<BenchmarkResult> {
	if (runs.length === 0) return []

	const caseCount = runs[0]!.length
	const aggregated: Array<BenchmarkResult> = []

	for (let caseIndex = 0; caseIndex < caseCount; caseIndex++) {
		const samples = runs.map((run) => run[caseIndex]!)
		const first = samples[0]!

		aggregated.push({
			name: first.name,
			iterations: first.iterations,
			mean: median(samples.map((sample) => sample.mean)),
			median: median(samples.map((sample) => sample.median)),
			p95: median(samples.map((sample) => sample.p95)),
			min: median(samples.map((sample) => sample.min)),
			max: median(samples.map((sample) => sample.max)),
			opsPerSecond: median(samples.map((sample) => sample.opsPerSecond)),
			total: median(samples.map((sample) => sample.total)),
		})
	}

	return aggregated
}

function printTable(results: Array<BenchmarkResult>, options: CliOptions): void {
	const rows = results.map((result) => {
		const testCase = benchmarkCases.find((test) => test.name === result.name)
		return {
			benchmark: result.name,
			weight: String(testCase?.weight ?? 1),
			iterations: String(result.iterations),
			mean: `${result.mean.toFixed(4)}ms`,
			median: `${result.median.toFixed(4)}ms`,
			p95: `${result.p95.toFixed(4)}ms`,
			trimmedMean: `${Math.min(result.p95, result.mean).toFixed(4)}ms`,
			ops: result.opsPerSecond.toFixed(1),
		}
	})

	const repeatLabel = options.repeats > 1 ? ` x${options.repeats} (median across runs)` : ""
	console.log(`Morphlex benchmark${options.thorough ? " (thorough)" : ""}${repeatLabel}`)
	console.table(rows)

	const summary = summarizeResults(results)
	console.log(`Weighted median: ${summary.weightedMedianMs.toFixed(4)}ms`)
	console.log(`Weighted p95: ${summary.weightedP95Ms.toFixed(4)}ms`)
	console.log(`Weighted trimmed mean: ${summary.trimmedMeanMs.toFixed(4)}ms`)
	console.log(`Total measured time: ${summary.totalMeasuredMs.toFixed(2)}ms`)
}

function main(): void {
	const options = parseOptions(process.argv.slice(2))
	const runs: Array<Array<BenchmarkResult>> = []

	for (let repeat = 0; repeat < options.repeats; repeat++) {
		const runResults: Array<BenchmarkResult> = []

		for (let i = 0; i < benchmarkCases.length; i++) {
			runResults.push(runCase(benchmarkCases[i]!, options))
		}

		runs.push(runResults)
	}

	const results = aggregateResults(runs)

	if (options.json) {
		console.log(JSON.stringify({ options, summary: summarizeResults(results), results }, null, 2))
		return
	}

	printTable(results, options)
}

main()