import { expect, test } from "bun:test"
import type { NodeSpec } from "../../testing/build-snapshot"
import { headingRhythm } from "./heading-rhythm"
import { lines, marked } from "./support/layout-cases"

const group = (id: string, y: number, above = 0, below = 40): NodeSpec => ({
	style: { "border-top-width": "1px", "border-top-style": "solid", "border-top-color": "#333" },
	rect: { x: 24, y, width: 560, height: 220 }, children: [
		{ tag: "p", text: "A previous paragraph with enough prose to be read as the closing block of the previous section.", rect: { x: 24, y: y + 10, width: 560, height: 48 }, lineRects: lines([550, 400], 24, y + 10) },
		{ id, tag: "h2", text: "Section heading", style: { "font-size": "28px" }, rect: { x: 24, y: y + 58 + above, width: 560, height: 36 } },
		{ tag: "p", text: "The introduced content belongs to this heading.", rect: { x: 24, y: y + 94 + above + below, width: 560, height: 48 } },
	],
})

test("#given multiple crowded headings beside healthy gaps #then only crowded headings report", () => {
	expect(marked(headingRhythm, [group("one", 0), group("two", 240), group("healthy", 480, 64, 16)])).toEqual(["#one", "#two"])
	expect(marked(headingRhythm, [group("one", 0, 64, 16), group("two", 240, 64, 16)])).toEqual([])
})

test("#given one crowded heading #then the page minimum prevents a single local judgement", () => {
	expect(marked(headingRhythm, [group("one", 0), group("two", 240)])).toEqual(["#one", "#two"])
	expect(marked(headingRhythm, [group("one", 0)])).toEqual([])
})

test("#given equal gaps under running prose #then headings still attach to the previous block", () => {
	expect(marked(headingRhythm, [group("one", 0, 24, 24), group("two", 240, 20, 24)])).toEqual(["#one", "#two"])
	expect(marked(headingRhythm, [group("one", 0, 24, 20), group("two", 240, 24, 20)])).toEqual([])
})

test("#given headings following headings rather than prose #then titling groups do not count", () => {
	const titles = (id: string, y: number) => {
		const g = group(id, y)
		return { ...g, children: (g.children ?? []).map((n, i) => i === 0 ? { ...n, tag: "h2" } : n) }
	}
	expect(marked(headingRhythm, [titles("one", 0), titles("two", 240)])).toEqual([])
})

test("#given short two line labels with even gaps #then they are not running prose", () => {
	const labels = (id: string, y: number) => {
		const g = group(id, y, 24, 24)
		return { ...g, children: (g.children ?? []).map((n, i) => i === 0 ? { ...n, text: "A short label" } : n) }
	}
	expect(marked(headingRhythm, [labels("one", 0), labels("two", 240)])).toEqual([])
})

test("#given a preceding label larger than its heading #then it is not folded into the heading", () => {
	const small = (id: string, y: number): NodeSpec => {
		const g = group(id, y)
		return { ...g, children: (g.children ?? []).map((n, i) => i === 0
			? { ...n, text: "Closing copy", style: { "font-size": "14px" }, rect: { x: 24, y: y + 10, width: 560, height: 24 } }
			: i === 1 ? { ...n, style: { "font-size": "13px" } } : n) }
	}
	expect(marked(headingRhythm, [small("one", 0), small("two", 240)])).toEqual(["#one", "#two"])
})

test("#given alike title rows separated by other content #then distant rows do not stop the neighbour walk", () => {
	const rows = (id: string, y: number): NodeSpec => {
		const g = group(id, y)
		const nodes = g.children ?? []
		const wrapped: NodeSpec[] = nodes.map((n, i) => i === 0 ? n : {
			attributes: { class: "row" }, rect: n.rect ?? {}, children: [n],
		})
		return { ...g, children: [...wrapped, { attributes: { class: "row" }, rect: { x: 24, y: y + 210, width: 560, height: 36 },
			children: [{ tag: "h2", text: "A later title", rect: { x: 24, y: y + 210, width: 560, height: 36 } }] }] }
	}
	expect(marked(headingRhythm, [rows("one", 0), rows("two", 300)])).toEqual(["#one", "#two"])
})