-- AltSystem Roll Logic
-- Handles /roll 20, captures the result, and applies modifiers.

AltSystem = AltSystem or {}

local pendingRollType = nil -- "attack" or "defense"

-- Perform a roll: triggers the WoW native /roll 20 command
function AltSystem:PerformRoll(rollType)
    pendingRollType = rollType
    RandomRoll(1, 20)
end

-- Listen for the system message that contains the roll result
local rollListener = CreateFrame("Frame")
rollListener:RegisterEvent("CHAT_MSG_SYSTEM")

rollListener:SetScript("OnEvent", function(self, event, message)
    if not pendingRollType then return end

    -- Match the roll result pattern: "PlayerName rolls X (1-20)"
    local roll = message:match("rolls (%d+) %(1%-20%)")
    if not roll then return end

    local rollValue = tonumber(roll)
    local rollType = pendingRollType
    pendingRollType = nil

    AltSystem:CalculateAndDisplayResult(rollType, rollValue)
end)

-- Calculate the final result based on the roll type and selected modifiers
function AltSystem:CalculateAndDisplayResult(rollType, rollValue)
    -- Critical rolls bypass normal calculation
    if rollValue == 1 then
        if AltSystem.ResultText then
            AltSystem.ResultText:SetText("|cffff0000Critical Failure|r")
        end
        return
    elseif rollValue == 20 then
        if AltSystem.ResultText then
            AltSystem.ResultText:SetText("|cff00ff00Critical Success|r")
        end
        return
    end

    local state = AltSystem.State
    local skill = AltSystem.Data.Skills[state.selectedSkillIndex]
    local item = AltSystem.Data.Items[state.selectedItemIndex]

    local skillMod = skill and skill.modifier or 0
    local itemMod = item and item.modifier or 0

    local total = rollValue
    local breakdown = "Roll: " .. rollValue

    if rollType == "attack" then
        -- Attack Roll = roll + skill modifier + item modifier
        total = rollValue + skillMod + itemMod

        breakdown = breakdown .. "\nSkill: " .. FormatModifier(skillMod)
        if itemMod ~= 0 then
            breakdown = breakdown .. "  |  Item: " .. FormatModifier(itemMod)
        end
        breakdown = breakdown .. "\n|cffffd100Attack Total: " .. total .. "|r"

    elseif rollType == "defense" then
        -- Defense Roll = roll + skill modifier + item modifier + defense modifier + shield modifier
        local defense = AltSystem.Data.Defenses[state.selectedDefenseIndex]
        local defenseMod = defense and defense.modifier or 0
        local shieldMod = state.shieldEnabled and AltSystem.Data.ShieldModifier or 0

        total = rollValue + skillMod + itemMod + defenseMod + shieldMod

        breakdown = breakdown .. "\nSkill: " .. FormatModifier(skillMod)
        if itemMod ~= 0 then
            breakdown = breakdown .. "  |  Item: " .. FormatModifier(itemMod)
        end
        breakdown = breakdown .. "\nDefense: " .. FormatModifier(defenseMod)
        if shieldMod ~= 0 then
            breakdown = breakdown .. "  |  Shield: " .. FormatModifier(shieldMod)
        end
        breakdown = breakdown .. "\n|cff00ccffDefense Total: " .. total .. "|r"
    end

    if AltSystem.ResultText then
        AltSystem.ResultText:SetText(breakdown)
    end
end

-- Format a modifier value with sign
function FormatModifier(value)
    if value >= 0 then
        return "+" .. value
    else
        return tostring(value)
    end
end