Fitnes-tracker/main.go

697 lines
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Go
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2025-12-04 12:51:08 +00:00
package main
import (
"database/sql"
"encoding/json"
"html/template"
"log"
"net/http"
"strconv"
"time"
_ "github.com/mattn/go-sqlite3"
)
var (
db *sql.DB
indexTmpl *template.Template
listenAddr = ":8080"
databaseFile = "fitness.db"
)
type SetRow struct {
ID int
Exercise string
Reps int
Weight float64
StartedAt time.Time
}
func main() {
var err error
// Open SQLite DB
db, err = sql.Open("sqlite3", databaseFile)
if err != nil {
log.Fatal("open db:", err)
}
defer db.Close()
if err := initDB(); err != nil {
log.Fatal("init db:", err)
}
// Parse template with helper funcs
indexTmpl = template.Must(template.New("index").Funcs(template.FuncMap{
"add": func(a, b int) int { return a + b },
}).Parse(indexHTML))
// Routes
http.HandleFunc("/", handleIndex)
http.HandleFunc("/start", handleStartWorkout)
http.HandleFunc("/add-set", handleAddSet)
// APIs
http.HandleFunc("/api/rest-times", handleRestTimes)
http.HandleFunc("/api/volume", handleVolumeStats)
log.Printf("Listening on %s ...", listenAddr)
if err := http.ListenAndServe(listenAddr, nil); err != nil {
log.Fatal(err)
}
}
func initDB() error {
// Very simple schema
schema := `
CREATE TABLE IF NOT EXISTS workouts (
id INTEGER PRIMARY KEY AUTOINCREMENT,
started_at TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS sets (
id INTEGER PRIMARY KEY AUTOINCREMENT,
workout_id INTEGER NOT NULL,
exercise TEXT NOT NULL,
reps INTEGER NOT NULL,
weight REAL NOT NULL,
started_at TEXT NOT NULL,
FOREIGN KEY(workout_id) REFERENCES workouts(id)
);
`
_, err := db.Exec(schema)
return err
}
// --- Handlers ---
func handleIndex(w http.ResponseWriter, r *http.Request) {
latestID, err := getLatestWorkoutID()
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
var sets []SetRow
if latestID != 0 {
sets, err = getSetsForWorkout(latestID)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
}
data := struct {
HasWorkout bool
WorkoutID int
Sets []SetRow
}{
HasWorkout: latestID != 0,
WorkoutID: latestID,
Sets: sets,
}
if err := indexTmpl.Execute(w, data); err != nil {
log.Println("template error:", err)
}
}
func handleStartWorkout(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodPost {
http.Redirect(w, r, "/", http.StatusSeeOther)
return
}
now := time.Now().UTC().Format(time.RFC3339)
_, err := db.Exec(`INSERT INTO workouts (started_at) VALUES (?)`, now)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
http.Redirect(w, r, "/", http.StatusSeeOther)
}
func handleAddSet(w http.ResponseWriter, r *http.Request) {
if r.Method != http.MethodPost {
http.Redirect(w, r, "/", http.StatusSeeOther)
return
}
// Always attach to latest workout
workoutID, err := getLatestWorkoutID()
if err != nil || workoutID == 0 {
http.Error(w, "no active workout", http.StatusBadRequest)
return
}
exercise := r.FormValue("exercise")
repsStr := r.FormValue("reps")
weightStr := r.FormValue("weight")
if exercise == "" || repsStr == "" || weightStr == "" {
http.Error(w, "missing fields", http.StatusBadRequest)
return
}
reps, err := strconv.Atoi(repsStr)
if err != nil {
http.Error(w, "invalid reps", http.StatusBadRequest)
return
}
weight, err := strconv.ParseFloat(weightStr, 64)
if err != nil {
http.Error(w, "invalid weight", http.StatusBadRequest)
return
}
now := time.Now().UTC().Format(time.RFC3339)
_, err = db.Exec(
`INSERT INTO sets (workout_id, exercise, reps, weight, started_at)
VALUES (?, ?, ?, ?, ?)`,
workoutID, exercise, reps, weight, now,
)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
http.Redirect(w, r, "/", http.StatusSeeOther)
}
// --- API: rest times between sets (latest workout) ---
func handleRestTimes(w http.ResponseWriter, r *http.Request) {
workoutID, err := getLatestWorkoutID()
if err != nil || workoutID == 0 {
http.Error(w, "no workout", http.StatusBadRequest)
return
}
rows, err := db.Query(
`SELECT id, started_at FROM sets WHERE workout_id = ? ORDER BY started_at`,
workoutID,
)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
defer rows.Close()
type simpleSet struct {
ID int
StartedAt time.Time
}
var sets []simpleSet
for rows.Next() {
var id int
var startedStr string
if err := rows.Scan(&id, &startedStr); err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
t, err := time.Parse(time.RFC3339, startedStr)
if err != nil {
http.Error(w, "time parse error", http.StatusInternalServerError)
return
}
sets = append(sets, simpleSet{ID: id, StartedAt: t})
}
if err := rows.Err(); err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
// Compute rest times (seconds) between sets
var labels []string
var data []float64
for i := 1; i < len(sets); i++ {
delta := sets[i].StartedAt.Sub(sets[i-1].StartedAt).Seconds()
if delta < 0 {
delta = 0
}
labels = append(labels, "Set "+strconv.Itoa(i+1))
data = append(data, delta)
}
resp := struct {
Labels []string `json:"labels"`
Data []float64 `json:"data"`
}{
Labels: labels,
Data: data,
}
w.Header().Set("Content-Type", "application/json")
_ = json.NewEncoder(w).Encode(resp)
}
// --- API: volume stats (day / week / month) ---
func handleVolumeStats(w http.ResponseWriter, r *http.Request) {
rangeParam := r.URL.Query().Get("range")
if rangeParam == "" {
rangeParam = "day"
}
now := time.Now()
var curStart, curEnd time.Time
switch rangeParam {
case "week":
// Start of ISO week (Monday)
weekday := int(now.Weekday())
if weekday == 0 {
weekday = 7 // Sunday
}
curStart = time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).
AddDate(0, 0, -(weekday - 1))
curEnd = curStart.AddDate(0, 0, 7)
case "month":
curStart = time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
curEnd = curStart.AddDate(0, 1, 0)
default: // "day"
curStart = time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
curEnd = curStart.AddDate(0, 0, 1)
rangeParam = "day"
}
// Previous period of same length
period := curEnd.Sub(curStart)
prevEnd := curStart
prevStart := prevEnd.Add(-period)
currentVol, err := queryVolume(curStart, curEnd)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
prevVol, err := queryVolume(prevStart, prevEnd)
if err != nil {
http.Error(w, "db error", http.StatusInternalServerError)
return
}
percentChange := 0.0
hasPrevious := prevVol > 0
if hasPrevious {
percentChange = (currentVol - prevVol) / prevVol * 100.0
}
resp := struct {
Range string `json:"range"`
CurrentVolume float64 `json:"current_volume"`
PreviousVolume float64 `json:"previous_volume"`
PercentChange float64 `json:"percent_change"`
HasPrevious bool `json:"has_previous"`
CurrentLabel string `json:"current_label"`
PreviousLabel string `json:"previous_label"`
}{
Range: rangeParam,
CurrentVolume: currentVol,
PreviousVolume: prevVol,
PercentChange: percentChange,
HasPrevious: hasPrevious,
CurrentLabel: curStart.Format("2006-01-02"),
PreviousLabel: prevStart.Format("2006-01-02"),
}
w.Header().Set("Content-Type", "application/json")
_ = json.NewEncoder(w).Encode(resp)
}
func queryVolume(start, end time.Time) (float64, error) {
// Sum of (reps * weight) for sets whose started_at is in [start, end)
startStr := start.UTC().Format(time.RFC3339)
endStr := end.UTC().Format(time.RFC3339)
row := db.QueryRow(`
SELECT COALESCE(SUM(reps * weight), 0)
FROM sets
WHERE started_at >= ? AND started_at < ?
`, startStr, endStr)
var vol float64
if err := row.Scan(&vol); err != nil {
return 0, err
}
return vol, nil
}
// --- Helpers ---
func getLatestWorkoutID() (int, error) {
row := db.QueryRow(`SELECT id FROM workouts ORDER BY id DESC LIMIT 1`)
var id int
err := row.Scan(&id)
if err == sql.ErrNoRows {
return 0, nil
}
return id, err
}
func getSetsForWorkout(workoutID int) ([]SetRow, error) {
rows, err := db.Query(
`SELECT id, exercise, reps, weight, started_at
FROM sets
WHERE workout_id = ?
ORDER BY started_at`,
workoutID,
)
if err != nil {
return nil, err
}
defer rows.Close()
var out []SetRow
for rows.Next() {
var s SetRow
var startedStr string
if err := rows.Scan(&s.ID, &s.Exercise, &s.Reps, &s.Weight, &startedStr); err != nil {
return nil, err
}
t, err := time.Parse(time.RFC3339, startedStr)
if err != nil {
return nil, err
}
s.StartedAt = t
out = append(out, s)
}
return out, rows.Err()
}
// --- HTML template (single page) ---
const indexHTML = `
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Minimal Fitness Tracker</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
body {
font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
max-width: 900px;
margin: 0 auto;
padding: 1rem;
background: #111827;
color: #e5e7eb;
}
h1 { margin-bottom: 0.5rem; }
.card {
background: #1f2937;
border-radius: 0.75rem;
padding: 1rem 1.25rem;
margin-bottom: 1rem;
}
label { display:block; margin-top: 0.5rem; }
input[type="text"],
input[type="number"],
select {
width: 100%;
padding: 0.4rem 0.5rem;
border-radius: 0.375rem;
border: 1px solid #374151;
background: #111827;
color: #e5e7eb;
}
button {
margin-top: 0.75rem;
padding: 0.4rem 0.9rem;
border-radius: 0.375rem;
border: none;
background: #3b82f6;
color: white;
cursor: pointer;
}
button:hover { background: #2563eb; }
table {
width: 100%;
border-collapse: collapse;
margin-top: 0.5rem;
}
th, td {
border-bottom: 1px solid #374151;
padding: 0.4rem 0.3rem;
text-align: left;
}
th { font-size: 0.85rem; text-transform: uppercase; color:#9ca3af; }
canvas {
max-width: 100%;
background: #111827;
border-radius: 0.75rem;
padding: 0.5rem;
}
.badge {
display:inline-block;
padding: 0.15rem 0.5rem;
border-radius: 999px;
font-size: 0.75rem;
background:#111827;
color:#9ca3af;
}
.row {
display: grid;
grid-template-columns: 1fr;
gap: 1rem;
}
@media (min-width: 768px) {
.row {
grid-template-columns: 1.1fr 0.9fr;
}
}
</style>
</head>
<body>
<h1>Minimal Fitness Tracker</h1>
<p style="color:#9ca3af;">Simple self-hosted Go app log sets, see rest times and training volume.</p>
<div class="row">
<div>
<div class="card">
<h2>Workout</h2>
{{if .HasWorkout}}
<p>Current workout ID: <span class="badge">{{.WorkoutID}}</span></p>
{{else}}
<p>No workout yet.</p>
{{end}}
<form method="POST" action="/start">
<button type="submit">Start new workout</button>
</form>
</div>
<div class="card">
<h2>Add set</h2>
{{if .HasWorkout}}
<form method="POST" action="/add-set">
<label>
Exercise
<input type="text" name="exercise" placeholder="Squat" required>
</label>
<label>
Reps
<input type="number" name="reps" min="1" step="1" required>
</label>
<label>
Weight (kg)
<input type="number" name="weight" step="0.5" min="0" required>
</label>
<button type="submit">Save set</button>
</form>
{{else}}
<p style="color:#fbbf24;">Start a workout first.</p>
{{end}}
</div>
<div class="card">
<h2>Sets in latest workout</h2>
{{if .Sets}}
<table>
<thead>
<tr>
<th>#</th>
<th>Exercise</th>
<th>Reps</th>
<th>Weight</th>
<th>Time (UTC)</th>
</tr>
</thead>
<tbody>
{{range $i, $s := .Sets}}
<tr>
<td>{{add $i 1}}</td>
<td>{{$s.Exercise}}</td>
<td>{{$s.Reps}}</td>
<td>{{$s.Weight}}</td>
<td>{{$s.StartedAt.Format "15:04:05"}}</td>
</tr>
{{end}}
</tbody>
</table>
{{else}}
<p>No sets logged yet.</p>
{{end}}
</div>
</div>
<div>
<div class="card">
<h2>Rest time between sets (latest workout)</h2>
<canvas id="restChart" height="120"></canvas>
<p id="restInfo" style="font-size:0.85rem; color:#9ca3af; margin-top:0.3rem;"></p>
</div>
<div class="card">
<h2>Training volume (Σ weight × reps)</h2>
<label for="rangeSelect">View range</label>
<select id="rangeSelect" onchange="loadVolumeStats()">
<option value="day">Today vs yesterday</option>
<option value="week">This week vs last week</option>
<option value="month">This month vs last month</option>
</select>
<canvas id="volumeChart" height="120" style="margin-top:0.5rem;"></canvas>
<p id="volumeInfo" style="font-size:0.85rem; color:#9ca3af; margin-top:0.3rem;"></p>
</div>
</div>
</div>
<!-- Chart.js from CDN -->
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
<script>
let restChartInstance = null;
let volumeChartInstance = null;
function loadRestTimes() {
fetch('/api/rest-times')
.then(res => {
if (!res.ok) {
throw new Error("No rest data yet");
}
return res.json();
})
.then(data => {
const ctx = document.getElementById('restChart').getContext('2d');
if (!data || !data.labels || data.labels.length === 0) {
document.getElementById('restInfo').textContent =
'Log at least two sets to see rest times.';
return;
}
if (restChartInstance) {
restChartInstance.destroy();
}
restChartInstance = new Chart(ctx, {
type: 'bar',
data: {
labels: data.labels,
datasets: [{
label: 'Rest (seconds)',
data: data.data
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
});
const avg = data.data.reduce((a,b)=>a+b,0) / data.data.length;
document.getElementById('restInfo').textContent =
'Average rest: ' + avg.toFixed(1) + ' s';
})
.catch(err => {
document.getElementById('restInfo').textContent =
'No rest data yet add some sets.';
});
}
function loadVolumeStats() {
const range = document.getElementById('rangeSelect').value;
fetch('/api/volume?range=' + encodeURIComponent(range))
.then(res => {
if (!res.ok) {
throw new Error("No volume data");
}
return res.json();
})
.then(data => {
const ctx = document.getElementById('volumeChart').getContext('2d');
if (volumeChartInstance) {
volumeChartInstance.destroy();
}
volumeChartInstance = new Chart(ctx, {
type: 'bar',
data: {
labels: [data.previous_label, data.current_label],
datasets: [{
label: 'Volume (kg × reps)',
data: [data.previous_volume, data.current_volume]
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
});
let text = '';
const current = data.current_volume;
const previous = data.previous_volume;
const prettyRange =
data.range === 'day' ? 'today' :
data.range === 'week' ? 'this week' :
'this month';
if (!data.has_previous) {
text = 'Total volume ' + prettyRange + ': ' + current.toFixed(1) +
' (no previous period logged).';
} else {
const change = data.percent_change;
let dir = 'no change';
let arrow = '';
if (change > 1e-6) {
dir = 'up';
arrow = '▲';
} else if (change < -1e-6) {
dir = 'down';
arrow = '▼';
}
text = 'Total volume ' + prettyRange + ': ' + current.toFixed(1) +
' (previous: ' + previous.toFixed(1) +
'). Change: ' + dir + ' ' + arrow + ' ' +
change.toFixed(1) + '%.';
}
document.getElementById('volumeInfo').textContent = text;
})
.catch(err => {
document.getElementById('volumeInfo').textContent =
'No volume data yet log some sets.';
});
}
document.addEventListener('DOMContentLoaded', () => {
loadRestTimes();
loadVolumeStats();
});
</script>
</body>
</html>
`