Implement analytics feature

Add server-side visit analytics collection, a public-page ping endpoint,
and a full-screen AnalyticsView for admins.

Backend:
- Add pagerite/analytics.py: Analytics/Visit model, Store, and persistence
- Wire /_a ping endpoint and GET /_api/analytics into pagerite/app.py

Frontend:
- Add full-screen AnalyticsView with visitor charts and transition map
- Add VisitorCharts and TransitionGraph subcomponents
- Add analytics JS helpers in frontend/src/analytics/
- Send navigation pings from frontend/src/pagerite.js
- Mount AnalyticsView from frontend/src/main.js
- Document the feature in docs/analytics.md and update AGENTS.md
This commit is contained in:
2026-08-20 18:43:57 +00:00
parent 11f8de2df5
commit b4e8fad090
16 changed files with 1932 additions and 17 deletions
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/**
* Radial transition map and helpers.
*
* Radial site map: the front page at the center, each slug level on its own
* ring. All pages of the site are shown (from /_api/pages), plus any extra
* paths seen in transitions (deleted pages); siblings run clockwise in
* navigation order, starting at the top. Internal path -> path transitions
* join opposite directions into straight connections (middle width = total
* count, wrapping the node circles at both ends); external referers/exits
* are not shown (yet). Self-loops (reload pings) are also skipped.
*/
export const TNODE_R = 34 // node circles hold the slug and the view count
/** Flatten the site tree into navigation order via DFS. */
function buildNavigationOrder(pageTree) {
const order = new Map()
const walk = (items) => {
for (const item of items || []) {
const p = `/${item.path}`
if (!order.has(p)) order.set(p, order.size)
walk(item.children)
}
}
walk(pageTree)
return order
}
/** Map page paths to their article titles from the site tree. */
function buildTitleMap(pageTree) {
const titles = new Map()
const walk = (items) => {
for (const item of items || []) {
titles.set(`/${item.path}`, item.title)
walk(item.children)
}
}
walk(pageTree)
return titles
}
/** Extract internal page-to-page transitions, excluding self-loops. */
function collectInternalTransitions(transitions) {
const internal = []
for (const [fr, tos] of Object.entries(transitions || {})) {
if (!fr.startsWith('/')) continue
for (const [to, count] of Object.entries(tos)) {
if (to.startsWith('/') && to !== fr) internal.push({ fr, to, count })
}
}
return internal
}
/** Build nodes with depth and a path lookup map; children are wired to parents. */
function buildNodeTree(internal, navOrder) {
const paths = new Set(['/', ...navOrder.keys()])
for (const e of internal) { paths.add(e.fr); paths.add(e.to) }
const depth = (p) => (p === '/' ? 0 : p.split('/').length - 1)
const nodes = [...paths].map((p) => ({
path: p, depth: depth(p), angle: 0, children: [],
}))
const byPath = new Map(nodes.map((n) => [n.path, n]))
// Parent is the nearest ancestor present in the map, front page last.
const parentOf = (p) => {
let q = p
while (q !== '/') {
q = q.slice(0, q.lastIndexOf('/')) || '/'
if (byPath.has(q)) return byPath.get(q)
}
return byPath.get('/')
}
for (const n of nodes) {
if (n.path !== '/') parentOf(n.path).children.push(n)
}
return { nodes, byPath, root: byPath.get('/') }
}
/** Sort children by navigation order and compute each subtree's angular weight. */
function prepareWeights(root, navOrder) {
const byNav = (a, b) =>
(navOrder.get(a.path) ?? Infinity) - (navOrder.get(b.path) ?? Infinity)
|| a.path.localeCompare(b.path)
const weight = (n) =>
n.children.length ? n.children.reduce((s, k) => s + weight(k), 0) : 1 / n.depth
const walkSort = (n) => {
n.children.sort(byNav)
n.children.forEach(walkSort)
}
walkSort(root)
return weight
}
/** Assign angles clockwise starting from the top (-PI/2). */
function layoutAngles(root, unit, weight) {
const lay = (n, a0) => {
n.angle = a0
let a = a0
for (const k of n.children) {
lay(k, a)
a += weight(k) * unit
}
}
let a = -Math.PI / 2
for (const k of root.children) {
lay(k, a)
a += weight(k) * unit
}
}
/** Compute radial positions, view counts and labels for each node. */
function positionNodes(nodes, maxDepth, unit, viewsData, titles) {
// Constant radial gap between rings, equal to the arc spacing of nodes
// along a ring: leaf arc = unit * GAP, so GAP scales up with `unit` on
// sparse trees (where closing the circle forces wider arcs) and with
// 1/unit on dense ones (keeping arcs at the node clearance).
const CLEAR = 2 * TNODE_R + 12
const GAP = CLEAR * Math.max(unit, 1 / unit)
const radius = (d) => d * GAP
const viewCount = (p) => {
let n = 0
for (const c of Object.values(viewsData?.[p] || {})) n += c
return n
}
for (const n of nodes) {
const r = radius(n.depth)
n.x = Math.cos(n.angle) * r
n.y = Math.sin(n.angle) * r
n.views = viewCount(n.path)
// Slug inside the circle; full title goes on the link title attribute.
const slug = n.path === '/' ? '🏠' : n.path.split('/').pop()
n.label = slug.length > 11 ? `${slug.slice(0, 10)}` : slug
n.title = titles.get(n.path) || ''
}
return { radius, GAP }
}
/**
* Family structure at a glance: a radial spoke from each parent to its
* first child, and a ring arc across each sibling group from first to last
* child in navigation (clockwise) order.
*/
function buildFamilyArcs(nodes, radius) {
const arcs = []
for (const n of nodes) {
if (!n.children.length) continue
// The spoke aims along the FIRST CHILD's angle (the node's own angle
// coincides with it, except for the center page which has none).
const first = n.children[0]
const r1 = radius(n.depth) + TNODE_R
const r2 = radius(first.depth) - TNODE_R
arcs.push({
d: `M ${Math.cos(first.angle) * r1} ${Math.sin(first.angle) * r1} `
+ `L ${Math.cos(first.angle) * r2} ${Math.sin(first.angle) * r2}`,
})
if (n.children.length < 2) continue
const r = radius(n.children[0].depth)
const a0 = n.children[0].angle
const a1 = n.children[n.children.length - 1].angle
if (a1 - a0 >= 2 * Math.PI - 1e-6) continue // full circle: degenerate arc
const large = a1 - a0 > Math.PI ? 1 : 0
arcs.push({
d: `M ${Math.cos(a0) * r} ${Math.sin(a0) * r} `
+ `A ${r} ${r} 0 ${large} 1 ${Math.cos(a1) * r} ${Math.sin(a1) * r}`,
})
}
return arcs
}
/** Collapse opposite transition directions into one unordered pair per page pair. */
function aggregatePairs(internal) {
const pairs = new Map() // unordered pair key -> [countAB, countBA]
for (const e of internal) {
const forward = e.fr < e.to
const k = forward ? `${e.fr} ${e.to}` : `${e.to} ${e.fr}`
const c = pairs.get(k) || [0, 0]
c[forward ? 0 : 1] += e.count
pairs.set(k, c)
}
return pairs
}
const fmtPt = (p) => `${p[0].toFixed(2)} ${p[1].toFixed(2)}`
/** Build one ribbon edge between two nodes with counts ab and ba. */
function buildRibbon(a, b, ab, ba) {
const count = ab + ba
const len = Math.hypot(b.x - a.x, b.y - a.y) || 1
const ux = (b.x - a.x) / len
const uy = (b.y - a.y) / len
const nx = -uy
const ny = ux
// Half-width of the thin middle and radius of the node surround.
const wMid = 0.75 + 6.75 * (Math.min(count, 100) / 100) ** 1.5
const R2 = TNODE_R + 3
// Attachment points sit somewhat forward from the side of the node,
// leaving enough room for the surround to flow naturally into the flare.
const BETA = (65 * Math.PI) / 180
const END = R2 * Math.cos(BETA)
const wEnd = R2 * Math.sin(BETA)
// Fixed flare length, clamped so the two ends cannot overlap.
const FLARE = Math.min(36, Math.max(0, (len - 2 * END) / 2))
// Point on the connection centerline at distance t from A, offset s
// perpendicular to it.
const P = (t, s) => [
a.x + t * ux + s * nx,
a.y + t * uy + s * ny,
]
// Arc around a node from p to q the long way, passing its back side.
const wrap = (p, q, node, back) => {
const ang = (pt2) =>
Math.atan2(pt2[1] - node[1], pt2[0] - node[0])
const TAU = 2 * Math.PI
const da = ((ang(back) - ang(p)) % TAU + TAU) % TAU
const db = ((ang(q) - ang(p)) % TAU + TAU) % TAU
return `A ${R2} ${R2} 0 1 ${da < db ? 1 : 0} ${fmtPt(q)} `
}
// Build one side of a flare in node -> middle order.
const flarePoints = (endT, midT, s, dir) => {
const span = Math.abs(midT - endT)
const pEnd = P(endT, s * wEnd)
const pMid = P(midT, s * wMid)
// At the node, leave tangent to the circular surround.
// The circle radius at the attachment is locally:
// A: (+END, ±wEnd)
// B: (-END, ±wEnd)
// A perpendicular tangent pointing into the connection therefore has
// these centerline/normal components.
const tangentT = dir * wEnd / R2
const tangentS = -s * END / R2
const hEnd = span * 0.65
const hMid = span * 0.4
const cEnd = P(
endT + tangentT * hEnd,
s * wEnd + tangentS * hEnd,
)
// At the thin end, arrive parallel with the centerline.
const cMid = P(
midT - dir * hMid,
s * wMid,
)
return { pEnd, cEnd, cMid, pMid }
}
// Emit a cubic in either traversal direction. Reversing a cubic requires
// swapping its control points, rather than recalculating the geometry.
const curve = (f, reverse = false) => {
if (!reverse) {
return `C ${fmtPt(f.cEnd)} ${fmtPt(f.cMid)} ${fmtPt(f.pMid)} `
}
return `C ${fmtPt(f.cMid)} ${fmtPt(f.cEnd)} ${fmtPt(f.pEnd)} `
}
const LA = P(END, wEnd)
const RA = P(END, -wEnd)
const LB = P(len - END, wEnd)
const RB = P(len - END, -wEnd)
const aLeft = flarePoints(END, END + FLARE, 1, 1)
const bLeft = flarePoints(len - END, len - END - FLARE, 1, -1)
const bRight = flarePoints(len - END, len - END - FLARE, -1, -1)
const aRight = flarePoints(END, END + FLARE, -1, 1)
const d = `M ${fmtPt(LA)} `
+ curve(aLeft)
+ `L ${fmtPt(bLeft.pMid)} `
+ curve(bLeft, true)
+ wrap(LB, RB, [b.x, b.y], P(len + R2, 0))
+ curve(bRight)
+ `L ${fmtPt(aRight.pMid)} `
+ curve(aRight, true)
+ wrap(RA, LA, [a.x, a.y], P(-R2, 0))
+ 'Z'
return {
d,
title: `${a.path}${b.path}: ${count} (${ab} / ${ba})`,
}
}
/** Build ribbon edges for every aggregated page-to-page pair. */
function buildRibbonEdges(pairs, byPath) {
return [...pairs].map(([k, [ab, ba]]) => {
const [pf, pt] = k.split(' ')
const a = byPath.get(pf)
const b = byPath.get(pt)
return buildRibbon(a, b, ab, ba)
})
}
/** Parse a visit start timestamp, which may already be numeric or an ISO string. */
function visitStart(v) {
return typeof v.start === 'number' ? v.start : Date.parse(v.start)
}
/**
* Derive internal path -> path transitions from the visits list, optionally
* restricted to a time window. This is the only time-filterable source of
* transitions (the server-side aggregate has no per-transition timestamps).
* Re-visits within the same visit are not recorded in `trail`, so this yields
* first-seen navigation chains rather than every ping.
*/
export function buildTransitionsFromVisits(visits, t0, t1) {
const transitions = {}
for (const v of visits || []) {
const start = visitStart(v)
if ((t0 != null && start < t0) || (t1 != null && start >= t1)) continue
const path = [v.entry, ...(v.trail || [])].filter((p) => p?.startsWith('/'))
for (let i = 0; i < path.length - 1; i++) {
const fr = path[i]
const to = path[i + 1]
if (fr === to) continue
transitions[fr] = transitions[fr] || {}
transitions[fr][to] = (transitions[fr][to] || 0) + 1
}
}
return transitions
}
/** Keep only the 5-minute view buckets that fall inside [t0, t1). */
export function filterViewsByRange(views, t0, t1) {
const filtered = {}
for (const [path, buckets] of Object.entries(views || {})) {
const out = {}
for (const [k, c] of Object.entries(buckets)) {
const t = Date.parse(k)
if ((t0 == null || t >= t0) && (t1 == null || t < t1)) out[k] = c
}
if (Object.keys(out).length) filtered[path] = out
}
return filtered
}
/**
* Build the radial transition map model.
* Returns { nodes, edges, arcs, r } or null when there is nothing to show.
*/
export function buildTransitionGraph(data, pageTree) {
const internal = collectInternalTransitions(data?.transitions)
const navOrder = buildNavigationOrder(pageTree)
const titles = buildTitleMap(pageTree)
if (!internal.length && !navOrder.size) return null
const { nodes, byPath, root } = buildNodeTree(internal, navOrder)
const weightFn = prepareWeights(root, navOrder)
const unit = (2 * Math.PI) / weightFn(root)
layoutAngles(root, unit, weightFn)
const maxDepth = Math.max(1, ...nodes.map((n) => n.depth))
const { radius, GAP } = positionNodes(nodes, maxDepth, unit, data?.views, titles)
const arcs = buildFamilyArcs(nodes, radius)
const pairs = aggregatePairs(internal)
const edges = buildRibbonEdges(pairs, byPath)
// Tight bounding box of the actual nodes; edges and arcs stay within the
// node circles, so node bounds plus node radius are sufficient.
const pad = 16
const xs = nodes.map((n) => n.x)
const ys = nodes.map((n) => n.y)
const bounds = {
x0: Math.min(...xs) - TNODE_R - pad,
y0: Math.min(...ys) - TNODE_R - pad,
x1: Math.max(...xs) + TNODE_R + pad,
y1: Math.max(...ys) + TNODE_R + pad,
}
return {
nodes,
edges,
arcs,
bounds,
}
}