#  Weighted-Weighted Harmonic Mean (WWHM) difficulty algorithm
# Original idea from Tom Harding (Deger8) called "WT-144"
# No limits in rise or fall rate should be employed.
# MTP should not be used.
# ST = solvetime, T=target solvetime
# height = most recently solved block

# set constants
# N=60 # See Masari coin for live data with N=60
# T=600 # coin's Target solvetime. If this changes, nothing else needs to be changed.
# adjust=0.99 # 0.98 for N=30, 0.99 for N=60
#  k = (N+1)/2 *adjust * T # there is not a missing N.

# algorithm
d=0, t=0, j=0
previous_max=timestamp[height - N]
for ( i = height-N+1; i < height+1; i++) {  # (N most recent blocks)
    max_timestamp=max(timestamp[i], previous_max)
    solvetime = max_timestamp - previous_max
    solvetime=1 if solvetime < 1
    # for N=60, 10*T solvetimes drives difficulty too far down, so:
     solvetime = 10*T if solvetime > 10*T
     previous_max=max_timestamp
    j++
    t +=  solvetime * j
    d += D[i] # sum the difficulties this is how WWHM is different from Tom's WT.
}
t=T*N if t < T*N  # in case of startup weirdness, keep t reasonable
next_D = d * k / t