-- Parser checks for lib/data.lua.
-- Run from the repo root:  lua test/test_data.lua
-- Parsers are what break silently on a kernel or hardware change, so they are
-- what gets a test. Everything else in this project is verified by screenshot.

package.path = './?.lua;' .. package.path
local data = require 'lib.data'

-- lib.card uses Cairo globals (cairo_*, CAIRO_*) without requiring 'cairo'
-- itself, so those globals must exist before it loads. Conky provides them;
-- plain lua needs its loadable Cairo binding on the cpath first, exactly as
-- test/render.lua does.
package.cpath = '/usr/lib64/conky/lib?.so;' .. package.cpath
require 'cairo'

local function read(path)
  local f = assert(io.open(path, 'r'))
  local s = f:read('*a')
  f:close()
  return s
end

-- cpu_times: total and idle jiffies from the aggregate "cpu " line.
local total, idle = data.cpu_times(read('test/fixtures/proc_stat'))
-- 209094+2199+135469+11604898+24408+0+946 = 11977014
assert(total == 11977014, 'cpu total, got ' .. tostring(total))
-- idle field is the 4th value, 11604898; iowait (24408) counts as idle too
assert(idle == 11629306, 'cpu idle, got ' .. tostring(idle))

-- mem_info: values in kB, as the file gives them.
local mem = data.mem_info(read('test/fixtures/proc_meminfo'))
assert(mem.total == 31943076, 'mem total, got ' .. tostring(mem.total))
assert(mem.available == 25627088, 'mem available, got ' .. tostring(mem.available))
-- used is total minus available, which is what a user means by "used"
assert(mem.used == 6315988, 'mem used, got ' .. tostring(mem.used))

-- millidegrees: hwmon temp*_input is millidegrees C, rounded to whole degrees.
assert(data.millidegrees(read('test/fixtures/temp1_input')) == 53,
  'temp, got ' .. tostring(data.millidegrees(read('test/fixtures/temp1_input'))))
-- A missing or unreadable sensor must yield nil, not an error and not 0:
-- 0 degrees is a plausible reading and would be indistinguishable from failure.
assert(data.millidegrees(nil) == nil, 'nil input must give nil')
assert(data.millidegrees('') == nil, 'empty input must give nil')
assert(data.millidegrees('garbage') == nil, 'unparseable input must give nil')

-- CPU load is a delta between two samples, so the counter holds state.
-- The first call has no previous sample and must report nil, not a number:
-- any number it invented would be wrong, and 100% on startup looks like a
-- real spike.
local c = data.new_cpu_counter()
assert(c:sample(1000, 900) == nil, 'first sample must give nil')

-- Second sample: 100 more total jiffies, 50 of them idle, so 50% busy.
-- Held in a local first: calling sample() again inside the assert message would
-- advance the counter a third time.
local busy = c:sample(1100, 950)
assert(busy == 50.0, 'second sample, got ' .. tostring(busy))

-- A counter that did not advance means no elapsed time, not 0% load.
local c2 = data.new_cpu_counter()
c2:sample(1000, 900)
assert(c2:sample(1000, 900) == nil, 'zero delta must give nil, not a division by zero')

-- === Per-core CPU =========================================================
-- The aggregate line answers "how busy is the machine"; the equaliser needs
-- one entry per core. Both come from the same file, so they are parsed by the
-- same rules and differ only in which lines they read.
local percore = read('test/fixtures/proc_stat_percore')
local cores = data.per_cpu_times(percore)
assert(#cores == 4, 'one entry per cpuN line, got ' .. tostring(#cores))

-- cpu0: 6441+24+3225+1056496+1932+0+760 = 1068878 total, idle+iowait = 1058428
assert(cores[1].total == 1068878, 'core 0 total, got ' .. tostring(cores[1].total))
assert(cores[1].idle == 1058428, 'core 0 idle, got ' .. tostring(cores[1].idle))

-- Ordering matters: bar N must be core N, so the list follows the file.
assert(cores[2].total == 1066406, 'core 1 total, got ' .. tostring(cores[2].total))

-- The aggregate 'cpu ' line must NOT be counted as a core: it would draw a
-- bar for the aggregate line showing the average, which looks like a real core.
for i, c in ipairs(cores) do
  assert(c.total < 2000000, 'entry ' .. i .. ' looks like the aggregate line')
end

-- A counter per core is just another instance, which is why new_cpu_counter
-- holds its own previous sample rather than using a module-level one.
local c0 = data.new_cpu_counter()
assert(c0:sample(cores[1].total, cores[1].idle) == nil, 'first sample is nil')
local busy = c0:sample(cores[1].total + 100, cores[1].idle + 25)
assert(busy == 75.0, 'second sample 75%, got ' .. tostring(busy))

-- Malformed input yields an empty list, never an error: a raise here is a
-- blank dashboard.
assert(#data.per_cpu_times('') == 0, 'empty input gives an empty list')
assert(#data.per_cpu_times('garbage\nlines\n') == 0, 'garbage gives an empty list')
assert(#data.per_cpu_times(nil) == 0, 'nil gives an empty list')
-- A truncated line (fewer than the 5 fields the maths needs) is skipped
-- rather than producing a nonsense total.
assert(#data.per_cpu_times('cpu0 1 2\n') == 0, 'a short line is skipped')

-- === Cache files ==========================================================
-- df -P guarantees one line per mount with the mountpoint LAST, which is why
-- the parser takes the last field rather than the sixth: an NFS device is
-- 'server:/export' and a device name can carry surprises, but the mountpoint
-- is always at the end.
local fs = data.df_parse(read('test/fixtures/df_output'))
assert(#fs == 6, 'one entry per mount, got ' .. tostring(#fs))
assert(fs[1].mount == '/', 'first mount, got ' .. tostring(fs[1].mount))
assert(fs[1].pct == 84, 'root percent, got ' .. tostring(fs[1].pct))
assert(fs[1].size == 263174213632, 'root size in bytes, got ' .. tostring(fs[1].size))
assert(fs[1].used == 208111570944, 'root used, got ' .. tostring(fs[1].used))

-- The NFS rows are the reason the last field matters: a colon in the device
-- would break a parser splitting on punctuation.
assert(fs[4].mount == '/mnt/nfs/Library', 'nfs mount, got ' .. tostring(fs[4].mount))
assert(fs[4].pct == 79, 'nfs percent, got ' .. tostring(fs[4].pct))

-- The device field carries the server, which is what lets the disks card
-- label the two shares without an address hardcoded in the repo.
assert(fs[4].host == 'server-a', 'nfs host, got ' .. tostring(fs[4].host))
assert(fs[1].host == nil, 'a local device has no host, got ' .. tostring(fs[1].host))

-- A full filesystem is a real state, not an error.
assert(fs[6].pct == 100, 'a full mount reads 100, got ' .. tostring(fs[6].pct))

-- The header line must not become a row.
for _, e in ipairs(fs) do
  assert(e.mount ~= 'on' and e.mount ~= 'Mounted', 'the header leaked in as a row')
end

assert(#data.df_parse('') == 0, 'empty input gives an empty list')
assert(#data.df_parse(nil) == 0, 'nil gives an empty list')
-- A header with no rows is what a failed df produces.
assert(#data.df_parse('Filesystem 1-blocks Used Available Capacity Mounted on\n') == 0,
  'a header alone gives an empty list')

-- du -sh: total first, then children largest-first. The suffixes must be
-- converted, not string-sorted: '1.1G' outranks '245M' numerically and loses
-- to it alphabetically.
local cache = data.du_parse(read('test/fixtures/du_output'))
assert(cache.total, 'a total is parsed')
assert(cache.total.label == '1.6G', 'total label, got ' .. tostring(cache.total.label))
assert(#cache.items == 4, 'four children, got ' .. tostring(#cache.items))
assert(cache.items[1].name == 'mozilla', 'largest child, got ' .. tostring(cache.items[1].name))
assert(cache.items[1].label == '1.1G', 'its label, got ' .. tostring(cache.items[1].label))
assert(cache.items[2].name == 'pip', 'second child, got ' .. tostring(cache.items[2].name))

-- Sizes are compared as bytes, which is what makes 'biggest' meaningful.
assert(cache.items[1].bytes > cache.items[2].bytes, '1.1G must outrank 245M')
assert(cache.items[1].bytes > 1e9, 'a G suffix is about a billion bytes')
assert(cache.items[4].bytes < 1e8, 'an M suffix is far smaller')

-- Share of the total drives the highlight colour.
assert(cache.items[1].bytes / cache.total.bytes > 0.5,
  'mozilla dominates this fixture, which is what the highlight keys on')

assert(data.du_parse('') == nil, 'empty input gives nil')
assert(data.du_parse(nil) == nil, 'nil gives nil')

-- === card.truncate ========================================================
-- Truncation is by CHARACTER, not byte: slicing a UTF-8 string mid-sequence
-- emits an invalid byte that Cairo draws as a replacement box, and the name
-- that needed shortening is exactly the kind that carries accents.
local card = require 'lib.card'

assert(card.truncate('short', 10) == 'short', 'a short string is unchanged')
assert(card.truncate('exactlyten', 10) == 'exactlyten', 'a string at the limit is unchanged')
assert(card.truncate('abcdefghijkl', 10) == 'abcdefghi\u{2026}',
  'a long string is cut to limit-1 plus an ellipsis, got ' .. tostring(card.truncate('abcdefghijkl', 10)))

-- The multi-byte case: ten accented characters are 20 bytes, so a byte-based
-- slice would cut one in half and produce invalid UTF-8.
local accented = string.rep('\u{00E9}', 12)
local cut = card.truncate(accented, 10)
assert(cut == string.rep('\u{00E9}', 9) .. '\u{2026}',
  'accented input must cut on a character boundary, got ' .. tostring(cut))

assert(card.truncate(nil, 10) == '', 'nil truncates to empty')
assert(card.truncate('abc', 0) == '', 'a zero limit gives empty')

-- === Network rate =========================================================
-- Interface byte counters are cumulative, so a rate is a delta over elapsed
-- time. The first call has no previous sample and must report nil: any number
-- it invented would be wrong, and a spike at startup looks real.
local r = data.new_rate_counter()
assert(r:sample(1000, 100) == nil, 'first sample must give nil')

-- 2048 bytes over 2 seconds is 1024 B/s.
local rate = r:sample(3048, 102)
assert(rate == 1024, 'second sample, got ' .. tostring(rate))

-- A counter that went backwards means a wrap or an interface reset. It must
-- clamp to zero, never produce the huge positive an unsigned wrap implies:
-- one bogus sample poisons the shared autoscale for the whole window.
local r2 = data.new_rate_counter()
r2:sample(5000, 100)
assert(r2:sample(10, 102) == 0, 'a counter reset must give 0')

-- Two samples inside the same clock second. os.time() has whole-second
-- resolution against a 2s draw interval, so this happens in normal operation
-- and must not divide by zero.
local r3 = data.new_rate_counter()
r3:sample(1000, 500)
local same_second = r3:sample(2000, 500)
assert(same_second ~= nil and same_second >= 0,
  'a zero time delta must fall back to the draw interval, got ' .. tostring(same_second))

-- A missing interface reads nil, which must propagate rather than raise.
local r4 = data.new_rate_counter()
assert(r4:sample(nil, 100) == nil, 'a nil byte count gives nil')

-- The fallback interval is a constructor argument, and the widget passes
-- conky's real update_interval rather than letting it default. That is the
-- path that ships, so it is the path that gets a test: at a 5s interval the
-- same 2048 bytes must read as 409.6 B/s, not 1024.
local r5 = data.new_rate_counter(5)
r5:sample(1000, 100)
assert(r5:sample(3048, 100) == 2048 / 5,
  'an explicit fallback interval must be used, got ' .. tostring(r5:sample(3048, 100)))

print('test_data: all assertions passed')