1 files changed, 277 insertions, 0 deletions
diff --git a/src/duration-graph.js b/src/duration-graph.js
new file mode 100644
index 0000000..5d0bf85
--- /dev/null
+++ b/src/duration-graph.js
@@ -0,0 +1,277 @@
+'use strict'
+
+const fs = require('fs')
+const util = require('util')
+const processArgv = require('./process-argv')
+
+const {
+  updatePlaylistFormat,
+  isGroup, isItem,
+  getItemPathString,
+  flattenGrouplike
+} = require('./playlist-utils')
+
+const readFile = util.promisify(fs.readFile)
+
+const metrics = {}
+metrics.duration = Symbol('Duration')
+metrics.length = metrics.duration
+metrics.time = metrics.duration
+metrics.tracks = Symbol('# of tracks')
+metrics.items = metrics.tracks
+
+function getUncachedDurationOfItem(item) {
+  if (isGroup(item)) {
+    return item.items.reduce((a, b) => a + getDurationOfItem(b), 0)
+  } else {
+    if (item && item.metadata && item.metadata.duration) {
+      return item.metadata.duration
+    } else {
+      console.warn('Item missing metadata:', getItemPathString(item))
+      return 0
+    }
+  }
+}
+
+// This is mostly just to avoid logging out "item missing metadata" warnings
+// multiple times.
+function getDurationOfItem(item) {
+  if (metrics.duration in item === false) {
+    item[metrics.duration] = getUncachedDurationOfItem(item)
+  }
+
+  return item[metrics.duration]
+}
+
+function getTrackCount(item) {
+  if (metrics.tracks in item === false) {
+    if (isGroup(item)) {
+      item[metrics.tracks] = flattenGrouplike(item).items.length
+    } else {
+      item[metrics.tracks] = 1
+    }
+  }
+
+  return item[metrics.tracks]
+}
+
+const getHours = n => Math.floor(n / 3600)
+const getMinutes = n => Math.floor((n % 3600) / 60)
+const getSeconds = n => n % 60
+
+function wordFormatDuration(durationNumber) {
+  if (typeof durationNumber !== 'number') {
+    throw new Error('Non-number passed')
+  }
+
+  // oh yeah
+  const hours = getHours(durationNumber),
+        minutes = getMinutes(durationNumber),
+        seconds = getSeconds(durationNumber)
+
+  return [
+    hours ? `${hours} hours` : false,
+    minutes ? `${minutes} minutes` : false,
+    seconds ? `${seconds} seconds` : false
+  ].filter(Boolean).join(', ') || '(No length.)'
+}
+
+function digitalFormatDuration(durationNumber) {
+  if (typeof durationNumber !== 'number') {
+    throw new Error('Non-number passed')
+  }
+
+  const hours = getHours(durationNumber),
+        minutes = getMinutes(durationNumber),
+        seconds = getSeconds(durationNumber)
+
+  return [hours, minutes, seconds].filter(Boolean).length ? [
+    hours ? `${hours}` : false,
+    minutes ? `${minutes}`.padStart(2, '0') : '00',
+    seconds ? `${seconds}`.padStart(2, '0') : '00'
+  ].filter(Boolean).join(':') : '(No length.)'
+}
+
+function padStartList(strings) {
+  const len = strings.reduce((a, b) => Math.max(a, b.length), 0)
+  return strings.map(s => s.padStart(len, ' '))
+}
+
+function measureItem(item, metric) {
+  if (metric === metrics.duration) {
+    return getDurationOfItem(item)
+  } else if (metric === metrics.tracks) {
+    return getTrackCount(item)
+  } else {
+    throw new Error('Invalid metric: ' + metric)
+  }
+}
+
+function makePlaylistGraph(playlist, {
+  graphWidth = 60,
+  onlyFirst = 20,
+  metric = metrics.duration
+} = {}) {
+  const output = []
+
+  const wholePlaylistLength = measureItem(playlist, metric)
+
+  const briefFormatDuration = duration => {
+    if (metric === metrics.duration) {
+      return digitalFormatDuration(duration)
+    } else {
+      return duration.toString()
+    }
+  }
+
+  const longFormatDuration = duration => {
+    if (metric === metrics.duration) {
+      return wordFormatDuration(duration)
+    } else if (metric === metrics.tracks) {
+      return `${duration} tracks`
+    } else {
+      return duration.toString()
+    }
+  }
+
+  let topThings = playlist.items.map((item, i) => {
+    const duration = measureItem(item, metric)
+    const briefDuration = briefFormatDuration(duration)
+    return {item, duration, briefDuration}
+  })
+
+  topThings.sort((a, b) => b.duration - a.duration)
+
+  const ignoredThings = topThings.slice(onlyFirst)
+
+  topThings = topThings.slice(0, onlyFirst)
+
+  const displayLength = topThings.reduce((a, b) => a + b.duration, 0)
+
+  // Left-pad the brief durations so they're all the same length.
+  {
+    const len = topThings.reduce((a, b) => Math.max(a, b.briefDuration.length), 0)
+    for (const obj of topThings) {
+      obj.padDuration = obj.briefDuration.padStart(len, ' ')
+    }
+  }
+
+  let totalWidth = 0
+  for (let i = 0; i < topThings.length; i++) {
+    // Add a color to each item.
+    const colorCode = (i % 6) + 1
+    topThings[i].fgColor = `\x1b[3${colorCode}m`
+    topThings[i].bgColor = `\x1b[4${colorCode}m`
+
+    topThings[i].partOfWhole = 1 / displayLength * topThings[i].duration
+
+    let w = Math.floor(topThings[i].partOfWhole * graphWidth)
+    if (totalWidth < graphWidth) {
+      w = Math.max(1, w)
+    }
+    totalWidth += w
+    topThings[i].visualWidth = w
+  }
+
+  output.push('    Whole length: ' + longFormatDuration(wholePlaylistLength), '')
+
+  output.push('    ' + topThings.map(({ bgColor, fgColor, visualWidth }) => {
+    return bgColor + fgColor + '-'.repeat(visualWidth)
+  }).join('') + '\x1b[0m' + (ignoredThings.length ? ' *' : ''), '')
+
+  output.push('    Length by item:')
+
+  output.push(...topThings.map(({ item, padDuration, visualWidth, fgColor }) =>
+    `    ${fgColor}${
+      // Dim the row if it doesn't show up in the graph.
+      visualWidth === 0 ? '\x1b[2m- ' : '  '
+    }${padDuration}  ${item.name}\x1b[0m`
+  ))
+
+  if (ignoredThings.length) {
+    const totalDuration = ignoredThings.reduce((a, b) => a + b.duration, 0)
+    const dur = longFormatDuration(totalDuration)
+    output.push(
+      `    \x1b[2m(* Plus ${ignoredThings.length} skipped items, accounting `,
+      `       for ${dur}.)\x1b[0m`
+    )
+  }
+
+  if (topThings.some(x => x.visualWidth === 0)) {
+    output.push('',
+      '    (Items that are too short to show up on the',
+      '     visual graph are dimmed and marked with a -.)'
+    )
+  }
+
+  return output
+}
+
+async function main(args) {
+  if (args.length === 0) {
+    console.log("Usage: http-music duration-graph /path/to/processed-playlist.json")
+    return
+  }
+
+  let graphWidth = 60
+  let onlyFirst = 20
+  let metric = metrics.duration
+
+  await processArgv(args.slice(1), {
+    '-metric': util => {
+      const arg = util.nextArg()
+      if (Object.keys(metrics).includes(arg)) {
+        metric = metrics[arg]
+      } else {
+        console.warn('Didn\'t set metric because it isn\'t recognized:', arg)
+      }
+    },
+
+    '-measure': util => util.alias('-metric'),
+    'm': util => util.alias('-metric'),
+
+    '-graph-width': util => {
+      const arg = util.nextArg()
+      const newVal = parseInt(arg)
+      if (newVal > 0) {
+        graphWidth = newVal
+      } else {
+        console.warn('Didn\'t set graph width because it\'s not greater than 0:', arg)
+      }
+    },
+
+    '-width': util => util.alias('-graph-width'),
+    'w': util => util.alias('-graph-width'),
+
+    '-only-first': util => {
+      const arg = util.nextArg()
+      const newVal = parseInt(arg)
+      if (newVal > 0) {
+        onlyFirst = newVal
+      } else {
+        console.warn('You can\'t use the first *zero* tracks! -', arg)
+      }
+    },
+
+    '-only': util => util.alias('-only-first'),
+    'o': util => util.alias('-only-first'),
+    '-first': util => util.alias('-only-first'),
+    'f': util => util.alias('-only-first'),
+
+    '-all': util => {
+      onlyFirst = Infinity
+    },
+
+    'a': util => util.alias('-all')
+  })
+
+  const playlist = updatePlaylistFormat(JSON.parse(await readFile(args[0])))
+
+  for (const line of makePlaylistGraph(playlist, {
+    graphWidth, onlyFirst, metric
+  })) {
+    console.log(line)
+  }
+}
+
+module.exports = main