package judgment

// Searching for good names
// ------------------------
// Rebuttal == Contestation == ???
// Rebuttal has a nice length isonomy with Adhesion
// Contestation ain't in some dictionaries
// Contestation feels more natural to a french thinker
// Rebuttal may be a little (too) intense
//
// uint8 for grades
// ----------------
// Not sure about that.  Is it worth the hassle?  May change.  Advice welcome.
//

// ProposalAnalysis holds some data we need to compute the Score of a Proposal, and hence its Rank.
type ProposalAnalysis struct {
	TotalSize              uint64 `json:"totalSize"`         // total amount of judges|judgments across all grades
	MedianGrade            uint8  `json:"medianGrade"`       // 0 == "worst" grade, goes up to the amount of grades - 1
	MedianGroupSize        uint64 `json:"medianGroupSize"`   // in judges|judgments
	SecondMedianGrade      uint8  `json:"secondMedianGrade"` // used in Majority Judgment deliberation
	SecondGroupSize        uint64 `json:"secondGroupSize"`   // either adhesion or contestation, whichever is bigger
	SecondGroupSign        int    `json:"secondGroupSign"`   // -1 for contestation group, +1 for adhesion group
	AdhesionGroupGrade     uint8  `json:"adhesionGroupGrade"`
	AdhesionGroupSize      uint64 `json:"adhesionGroupSize"`
	ContestationGroupGrade uint8  `json:"contestationGroupGrade"`
	ContestationGroupSize  uint64 `json:"contestationGroupSize"`
	// Can't decide between Rebuttal and Contestation…  Help!
	//RebuttalGroupGrade uint8
	//RebuttalGroupSize  uint64
}

// Reset the ProposalAnalysis to default values.
func (analysis *ProposalAnalysis) Reset() {
	analysis.TotalSize = 0
	analysis.MedianGrade = 0
	analysis.MedianGroupSize = 0
	analysis.SecondMedianGrade = 0
	analysis.SecondGroupSize = 0
	analysis.SecondGroupSign = 0
	analysis.AdhesionGroupGrade = 0
	analysis.AdhesionGroupSize = 0
	analysis.ContestationGroupGrade = 0
	analysis.ContestationGroupSize = 0
}

// Run MUTATES THE ANALYSIS, but leaves the proposalTally intact, unchanged.
// MJ uses the low median by default (favors contestation), but there's a parameter if need be.
// This method is deemed complex by gocyclo ; there's no way around it.
func (analysis *ProposalAnalysis) Run(proposalTally *ProposalTally, favorContestation bool) {
	analysis.Reset()
	analysis.TotalSize = proposalTally.CountJudgments()
	if 0 == analysis.TotalSize {
		return
	}

	adjustedTotal := analysis.TotalSize
	if favorContestation {
		adjustedTotal = analysis.TotalSize - 1
	}
	medianIndex := adjustedTotal / 2 // Euclidean division
	startIndex := uint64(0)
	cursorIndex := uint64(0)
	for gradeIndex, gradeTally := range proposalTally.Tally {
		if 0 == gradeTally {
			continue
		}

		startIndex = cursorIndex
		cursorIndex += gradeTally
		if (startIndex < medianIndex) && (cursorIndex <= medianIndex) {
			analysis.ContestationGroupSize += gradeTally
			analysis.ContestationGroupGrade = uint8(gradeIndex)
		} else if (startIndex <= medianIndex) && (medianIndex < cursorIndex) {
			analysis.MedianGroupSize = gradeTally
			analysis.MedianGrade = uint8(gradeIndex)
		} else if (startIndex > medianIndex) && (medianIndex < cursorIndex) {
			analysis.AdhesionGroupSize += gradeTally
			if 0 == analysis.AdhesionGroupGrade {
				analysis.AdhesionGroupGrade = uint8(gradeIndex)
			}
		}
	}

	contestationIsBiggest := analysis.AdhesionGroupSize < analysis.ContestationGroupSize
	if favorContestation {
		contestationIsBiggest = analysis.AdhesionGroupSize <= analysis.ContestationGroupSize
	}
	if contestationIsBiggest {
		analysis.SecondMedianGrade = analysis.ContestationGroupGrade
		analysis.SecondGroupSize = analysis.ContestationGroupSize
		if 0 < analysis.SecondGroupSize {
			analysis.SecondGroupSign = -1
		}
	} else {
		analysis.SecondMedianGrade = analysis.AdhesionGroupGrade
		analysis.SecondGroupSize = analysis.AdhesionGroupSize
		if 0 < analysis.SecondGroupSize {
			analysis.SecondGroupSign = 1
		}
	}

}