From 09e38cd615b5aec0223488a1def610550376e3ce Mon Sep 17 00:00:00 2001
From: Rene Saarsoo <nene@triin.net>
Date: Sun, 20 Sep 2020 13:56:55 +0300
Subject: [PATCH] Replace power% field with intensity fraction

---
 src/ast.ts       |  2 +-
 src/parser.ts    | 16 +++++++++-------
 src/tokenizer.ts | 16 +++++++++-------
 src/tss.ts       | 16 +++++++---------
 4 files changed, 26 insertions(+), 24 deletions(-)

diff --git a/src/ast.ts b/src/ast.ts
index 2288481..3df5a02 100644
--- a/src/ast.ts
+++ b/src/ast.ts
@@ -10,6 +10,6 @@ export type Workout = {
 export type Interval = {
   type: IntervalLabelTokenValue;
   duration: number;
-  power: { from: number; to: number };
+  intensity: { from: number; to: number };
   cadence?: number;
 };
diff --git a/src/parser.ts b/src/parser.ts
index c51c720..63af0c0 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -58,11 +58,11 @@ const parseIntervalParams = (tokens: Token[]): [IntervalData, Token[]] => {
     } else if (token.type === "cadence") {
       data.cadence = token.value;
       tokens.shift();
-    } else if (token.type === "power") {
-      data.power = { from: token.value, to: token.value };
+    } else if (token.type === "intensity") {
+      data.intensity = { from: token.value, to: token.value };
       tokens.shift();
-    } else if (token.type === "power-range") {
-      data.power = { from: token.value[0], to: token.value[1] };
+    } else if (token.type === "intensity-range") {
+      data.intensity = { from: token.value[0], to: token.value[1] };
       tokens.shift();
     } else {
       break;
@@ -72,7 +72,7 @@ const parseIntervalParams = (tokens: Token[]): [IntervalData, Token[]] => {
   if (!("duration" in data)) {
     throw new Error("Duration not specified");
   }
-  if (!("power" in data)) {
+  if (!("intensity" in data)) {
     throw new Error("Power not specified");
   }
 
@@ -85,11 +85,13 @@ const parseIntervals = (tokens: Token[]): Interval[] => {
   while (tokens[0]) {
     const token = tokens.shift() as Token;
     if (token.type === "label" && isIntervalLabelTokenValue(token.value)) {
-      const [{ duration, power, cadence }, rest] = parseIntervalParams(tokens);
+      const [{ duration, intensity, cadence }, rest] = parseIntervalParams(
+        tokens
+      );
       intervals.push({
         type: token.value,
         duration,
-        power,
+        intensity,
         cadence,
       });
       tokens = rest;
diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index 628fc65..d09828d 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -29,14 +29,14 @@ export type TextToken = {
   value: string;
 };
 export type NumberToken = {
-  type: "power" | "cadence" | "duration";
+  type: "intensity" | "cadence" | "duration";
   value: number;
 };
-export type PowerRangeToken = {
-  type: "power-range";
+export type IntensityRangeToken = {
+  type: "intensity-range";
   value: [number, number];
 };
-export type Token = LabelToken | TextToken | NumberToken | PowerRangeToken;
+export type Token = LabelToken | TextToken | NumberToken | IntensityRangeToken;
 
 const toInteger = (str: string): number => {
   return parseInt(str.replace(/[^0-9]/, ""), 10);
@@ -47,6 +47,8 @@ const toSeconds = (str: string): number => {
   return seconds + minutes * 60 + (hours || 0) * 60 * 60;
 };
 
+const toFraction = (percentage: number): number => percentage / 100;
+
 const tokenizeValueParam = (text: string): Token => {
   if (/^[0-9:]+$/.test(text)) {
     return { type: "duration", value: toSeconds(text) };
@@ -55,11 +57,11 @@ const tokenizeValueParam = (text: string): Token => {
     return { type: "cadence", value: toInteger(text) };
   }
   if (/^[0-9]+%..[0-9]+%$/.test(text)) {
-    const [from, to] = text.split("..").map(toInteger);
-    return { type: "power-range", value: [from, to] };
+    const [from, to] = text.split("..").map(toInteger).map(toFraction);
+    return { type: "intensity-range", value: [from, to] };
   }
   if (/^[0-9]+%$/.test(text)) {
-    return { type: "power", value: toInteger(text) };
+    return { type: "intensity", value: toFraction(toInteger(text)) };
   }
   throw new Error(`Unrecognized parameter "${text}"`);
 };
diff --git a/src/tss.ts b/src/tss.ts
index 2398e66..fc741e4 100644
--- a/src/tss.ts
+++ b/src/tss.ts
@@ -8,9 +8,7 @@ import { Interval } from "./ast";
 // W - power in watts
 // IF - intensity factor (power / FTP)
 
-const steadyTss = (duration: number, power: number): number => {
-  const intensity = power / 100;
-
+const steadyTss = (duration: number, intensity: number): number => {
   return ((duration * intensity * intensity) / 3600) * 100;
 };
 
@@ -18,17 +16,17 @@ const rangeTss = (duration: number, from: number, to: number): number => {
   let score = 0;
   const step = 1;
   for (let i = 0; i < duration; i += step) {
-    let power = from + (to - from) * (i / duration);
-    score += steadyTss(step, power);
+    let intensity = from + (to - from) * (i / duration);
+    score += steadyTss(step, intensity);
   }
   return score;
 };
 
-const intervalTss = ({ duration, power }: Interval): number => {
-  if (power.from === power.to) {
-    return steadyTss(duration, power.from);
+const intervalTss = ({ duration, intensity }: Interval): number => {
+  if (intensity.from === intensity.to) {
+    return steadyTss(duration, intensity.from);
   } else {
-    return rangeTss(duration, power.from, power.to);
+    return rangeTss(duration, intensity.from, intensity.to);
   }
 };