local NanamiDPS = NanamiDPS
local DataStore = NanamiDPS.DataStore

local Parser = CreateFrame("Frame")
NanamiDPS.Parser = Parser

local validUnits = { ["player"] = true }
for i = 1, 4 do validUnits["party" .. i] = true end
for i = 1, 40 do validUnits["raid" .. i] = true end

local validPets = { ["pet"] = true }
for i = 1, 4 do validPets["partypet" .. i] = true end
for i = 1, 40 do validPets["raidpet" .. i] = true end

Parser.validUnits = validUnits
Parser.validPets = validPets

-----------------------------------------------------------------------
-- Threat calculation now delegated to ThreatEngine + ThreatCoefficients.
-- The engine handles stance/buff scanning, talent multipliers, and the
-- complete spell coefficient database. These wrappers remain for
-- backward compatibility with ProcessDamage/ProcessHealing.
-----------------------------------------------------------------------

function Parser:CalculateSpellThreat(source, spell, damage)
    if not damage or damage <= 0 then return 0 end
    local class = DataStore:GetClass(source)
    return NanamiDPS.ThreatEngine:CalculateLocalThreat(source, spell, damage, false, class)
end

function Parser:CalculateHealThreat(source, amount)
    if not amount or amount <= 0 then return 0 end
    local class = DataStore:GetClass(source)
    return NanamiDPS.ThreatEngine:CalculateLocalThreat(source, nil, amount, true, class)
end

local unit_cache = {}
function Parser:UnitByName(name)
    if unit_cache[name] and UnitName(unit_cache[name]) == name then
        return unit_cache[name]
    end
    for unit in pairs(validUnits) do
        if UnitName(unit) == name then
            unit_cache[name] = unit
            return unit
        end
    end
    for unit in pairs(validPets) do
        if UnitName(unit) == name then
            unit_cache[name] = unit
            return unit
        end
    end
    return nil
end

function Parser:ScanName(name)
    if not name then return nil end

    for unit in pairs(validUnits) do
        if UnitExists(unit) and UnitName(unit) == name then
            if UnitIsPlayer(unit) then
                local _, class = UnitClass(unit)
                DataStore:SetClass(name, class)
                return "PLAYER"
            end
        end
    end

    -- SuperWoW pet format: "PetName (OwnerName)"
    local match, _, owner = string.find(name, "%((.*)%)", 1)
    if match and owner then
        if Parser:ScanName(owner) == "PLAYER" then
            DataStore:SetClass(name, owner)
            return "PET"
        end
    end

    for unit in pairs(validPets) do
        if UnitExists(unit) and UnitName(unit) == name then
            if strsub(unit, 0, 3) == "pet" then
                DataStore:SetClass(name, UnitName("player"))
            elseif strsub(unit, 0, 8) == "partypet" then
                DataStore:SetClass(name, UnitName("party" .. strsub(unit, 9)))
            elseif strsub(unit, 0, 7) == "raidpet" then
                DataStore:SetClass(name, UnitName("raid" .. strsub(unit, 8)))
            end
            return "PET"
        end
    end

    if NanamiDPS.config and NanamiDPS.config.trackAllUnits then
        DataStore:SetClass(name, DataStore:GetClass(name) or "__other__")
        return "OTHER"
    end

    return nil
end

function Parser:ResolveSource(source)
    source = NanamiDPS.trim(source)

    local sourceType = self:ScanName(source)
    if not sourceType then return nil, nil end

    if NanamiDPS.config and NanamiDPS.config.mergePets and sourceType == "PET" then
        local ownerClass = DataStore:GetClass(source)
        if ownerClass and ownerClass ~= "__other__" and NanamiDPS.validClasses[DataStore:GetClass(ownerClass)] then
            return ownerClass, "Pet: " .. source
        elseif ownerClass and ownerClass ~= "__other__" then
            return ownerClass, "Pet: " .. source
        end
    end

    return source, nil
end

function Parser:ProcessDamage(source, spell, target, amount, school)
    if NanamiDPS.config and NanamiDPS.config.paused then return end
    if type(source) ~= "string" or not tonumber(amount) then return end
    source = NanamiDPS.trim(source)
    amount = tonumber(amount)

    if source == target then return end

    local resolvedSource, petPrefix = self:ResolveSource(source)
    if not resolvedSource then return end

    local finalSpell = petPrefix and (petPrefix .. ": " .. (spell or "")) or spell

    if not DataStore.inCombat then
        DataStore:StartCombat()
    end

    DataStore:AddDamage(resolvedSource, finalSpell, target, amount, school)

    local targetType = self:ScanName(target)
    if targetType == "PLAYER" then
        DataStore:AddDamageTaken(target, finalSpell, resolvedSource, amount, school)
    end

    local threatAmount = self:CalculateSpellThreat(source, spell, amount)
    DataStore:AddThreat(source, threatAmount)

    local TE = NanamiDPS.ThreatEngine
    local TC = NanamiDPS.ThreatCoefficients
    if TE then
        local targetKey = TE:GetCurrentTargetKey()
        if targetKey and not TE:IsAPIActiveForTarget(targetKey) then
            TE:AddLocalThreat(targetKey, source, threatAmount)

            if spell and TC and TC.tauntSpells and TC.tauntSpells[spell] then
                TE:HandleTaunt(source, targetKey)
            end
        end
    end

    DataStore:UpdateActivity(resolvedSource, GetTime())

    if targetType == "PLAYER" then
        self:FeedDeathLog(target, {
            time = GetTime(),
            source = resolvedSource,
            spell = finalSpell,
            amount = -amount,
            type = "damage",
            hp = self:GetUnitHP(target),
        })
    end

    self:ThrottledRefresh()
end

function Parser:ProcessHealing(source, spell, target, amount, school)
    if NanamiDPS.config and NanamiDPS.config.paused then return end
    if type(source) ~= "string" or not tonumber(amount) then return end
    source = NanamiDPS.trim(source)
    amount = tonumber(amount)

    local resolvedSource, petPrefix = self:ResolveSource(source)
    if not resolvedSource then return end

    local finalSpell = petPrefix and (petPrefix .. ": " .. (spell or "")) or spell

    local effective = amount
    local unitstr = self:UnitByName(target)
    if unitstr then
        effective = math.min(UnitHealthMax(unitstr) - UnitHealth(unitstr), amount)
    end

    if not DataStore.inCombat then
        DataStore:StartCombat()
    end

    DataStore:AddHealing(resolvedSource, finalSpell, target, amount, effective)

    local healThreat = self:CalculateHealThreat(source, effective)
    DataStore:AddThreat(source, healThreat)

    local TE = NanamiDPS.ThreatEngine
    if TE then
        local targetKey = TE:GetCurrentTargetKey()
        if targetKey and not TE:IsAPIActiveForTarget(targetKey) then
            TE:AddLocalThreat(targetKey, source, healThreat)
        end
    end

    DataStore:UpdateActivity(resolvedSource, GetTime())

    local targetType = self:ScanName(target)
    if targetType == "PLAYER" then
        self:FeedDeathLog(target, {
            time = GetTime(),
            source = resolvedSource,
            spell = finalSpell,
            amount = effective,
            type = "heal",
            hp = self:GetUnitHP(target),
        })
    end

    self:ThrottledRefresh()
end

function Parser:ProcessDeath(name)
    if not name then return end
    local nameType = self:ScanName(name)
    if nameType ~= "PLAYER" then return end

    local log = self:FlushDeathLog(name)
    DataStore:AddDeath(name, {
        time = GetTime(),
        timeStr = date("%H:%M:%S"),
        events = log,
    })

    self:ThrottledRefresh()
end

function Parser:ProcessDispel(source, spell, target, aura)
    if type(source) ~= "string" then return end
    source = NanamiDPS.trim(source)

    local resolvedSource = self:ResolveSource(source)
    if not resolvedSource then return end

    DataStore:AddDispel(resolvedSource, spell or NanamiDPS.L["Unknown"], target, aura)
    DataStore:UpdateActivity(resolvedSource, GetTime())

    self:ThrottledRefresh()
end

function Parser:ProcessInterrupt(source, spell, target, interrupted)
    if type(source) ~= "string" then return end
    source = NanamiDPS.trim(source)

    local resolvedSource = self:ResolveSource(source)
    if not resolvedSource then return end

    DataStore:AddInterrupt(resolvedSource, spell or NanamiDPS.L["Unknown"], target, interrupted)
    DataStore:UpdateActivity(resolvedSource, GetTime())

    self:ThrottledRefresh()
end

function Parser:GetUnitHP(name)
    local unit = self:UnitByName(name)
    if unit then
        return UnitHealth(unit), UnitHealthMax(unit)
    end
    return 0, 0
end

-- Throttle refresh callbacks to avoid excessive UI updates
Parser.lastRefreshTime = 0
local REFRESH_INTERVAL = 0.25

function Parser:ThrottledRefresh()
    local now = GetTime()
    if now - self.lastRefreshTime >= REFRESH_INTERVAL then
        self.lastRefreshTime = now
        NanamiDPS:FireCallback("refresh")
    end
end

-- Death log buffer: last 15 seconds of events per player
Parser.deathLogBuffer = {}
local DEATH_LOG_WINDOW = 15

function Parser:FeedDeathLog(name, entry)
    if not self.deathLogBuffer[name] then
        self.deathLogBuffer[name] = {}
    end
    table.insert(self.deathLogBuffer[name], entry)

    -- Trim old entries
    local now = GetTime()
    local buf = self.deathLogBuffer[name]
    while table.getn(buf) > 0 and (now - buf[1].time) > DEATH_LOG_WINDOW do
        table.remove(buf, 1)
    end
end

function Parser:FlushDeathLog(name)
    local log = self.deathLogBuffer[name] or {}
    self.deathLogBuffer[name] = {}
    return log
end

-- Combat state detection
local combatFrame = CreateFrame("Frame", "NanamiDPSCombatState", UIParent)
combatFrame:RegisterEvent("PLAYER_REGEN_DISABLED")
combatFrame:RegisterEvent("PLAYER_REGEN_ENABLED")

local pendingCombatEnd = false
local combatEndTimer = 0

combatFrame:SetScript("OnEvent", function()
    if event == "PLAYER_REGEN_DISABLED" then
        pendingCombatEnd = false
        if not DataStore.inCombat then
            DataStore:StartCombat()
        end
    elseif event == "PLAYER_REGEN_ENABLED" then
        pendingCombatEnd = true
        combatEndTimer = GetTime() + 2
    end
end)

combatFrame:SetScript("OnUpdate", function()
    if (this.tick or 1) > GetTime() then return end
    this.tick = GetTime() + 1

    if pendingCombatEnd and GetTime() >= combatEndTimer then
        pendingCombatEnd = false
        DataStore:StopCombat()
    end
end)