-- HealBot_Model.lua
-- Centralized Data Store and Observer System for HealBotBlue

-- Safe local wrappers to prevent native UIDropDownMenu concatenation crashes
-- when setting selected values on closed dropdowns during initialization.
function HealBot_UIDropDownMenu_SetSelectedID(frame, id, useValue)
    local wasNil = false
    if not UIDROPDOWNMENU_OPEN_MENU then
        UIDROPDOWNMENU_OPEN_MENU = "DropDownList1"
        wasNil = true
    end
    UIDropDownMenu_SetSelectedID(frame, id, useValue)
    if wasNil then
        UIDROPDOWNMENU_OPEN_MENU = nil
    end
end

-- HealBot_UIDropDownMenu_SetSelectedValue: Internal utility: HealBot_UIDropDownMenu_SetSelectedValue
function HealBot_UIDropDownMenu_SetSelectedValue(frame, value, useValue)
    local wasNil = false
    if not UIDROPDOWNMENU_OPEN_MENU then
        UIDROPDOWNMENU_OPEN_MENU = "DropDownList1"
        wasNil = true
    end
    UIDropDownMenu_SetSelectedValue(frame, value, useValue)
    if wasNil then
        UIDROPDOWNMENU_OPEN_MENU = nil
    end
end

HealBot_Model = {
    observers = {},
    units = {},
    
    -- Expose common lists for iteration
    partyMembers = {},
    raidMembers = {},
    playerPet = nil,
    target = nil,
    
    -- Integration maps
    unitGUIDs = {}, -- unit -> GUID
    guidUnits = {}  -- GUID -> unit
}

--------------------------------------------------------------------------------
-- Observer Pattern Implementation
--------------------------------------------------------------------------------

-- Supported Events:
-- "UNIT_HEALTH_CHANGED"
-- "UNIT_POWER_CHANGED"
-- "UNIT_AURA_CHANGED"
-- "UNIT_STATUS_CHANGED" (dead/ghost/offline)
-- "ROSTER_CHANGED"
-- "EQUIPMENT_CHANGED"
-- "INCOMING_HEAL_CHANGED"

-- HealBot_Model:RegisterObserver: Registers an observer callback for an event.
function HealBot_Model:RegisterObserver(event, callback)
    if not self.observers[event] then
        self.observers[event] = {}
    end
    table.insert(self.observers[event], callback)
end

-- HealBot_Model:NotifyObservers: Fires all registered callbacks for an event.
function HealBot_Model:NotifyObservers(event, unitID, arg1, arg2)
    if self.observers[event] then
        local len = table.getn(self.observers[event])
        for i = 1, len do
            self.observers[event][i](unitID, arg1, arg2)
        end
    end
end

--------------------------------------------------------------------------------
-- Model Initialization
--------------------------------------------------------------------------------

-- HealBot_Model:Initialize: Pre-allocates the unit state dictionary.
function HealBot_Model:Initialize()
    self:InitUnitState("player")
    self:InitUnitState("target")
    self:InitUnitState("pet")
    
    for i = 1, 4 do
        self:InitUnitState("party"..i)
        self:InitUnitState("partypet"..i)
        table.insert(self.partyMembers, "party"..i)
    end
    
    for i = 1, 40 do
        self:InitUnitState("raid"..i)
        self:InitUnitState("raidpet"..i)
        table.insert(self.raidMembers, "raid"..i)
    end
end

-- HealBot_Model:InitUnitState: Internal utility: HealBot_Model:InitUnitState
function HealBot_Model:InitUnitState(unit)
    if not self.units[unit] then
        self.units[unit] = {
            -- Base properties
            name = nil,
            class = nil,
            englishClass = nil,
            
            -- State tracking
            health = 0,
            maxHealth = 0,
            mana = 0,
            maxMana = 0,
            powerType = 0,
            
            -- Status tracking
            isDead = false,
            isGhost = false,
            isConnected = true,
            inRange = false,
            
            -- Buffs/Debuffs (Auras)
            debuffType = nil,
            debuffTexture = nil,
            missingBuff = false,
            icons = {},
            
            -- Integration
            incomingHeal = 0
        }
    end
end

--------------------------------------------------------------------------------
-- Model Updaters (Called by Controller)
--------------------------------------------------------------------------------

-- Updates base unit info (Name, Class)
function HealBot_Model:UpdateUnitIdentity(unit)
    if not self.units[unit] then return false end
    
    local oldName = self.units[unit].name
    local oldEnglishClass = self.units[unit].englishClass
    local name = UnitName(unit)
    local _, englishClass = UnitClass(unit)
    
    if oldName ~= name or oldEnglishClass ~= englishClass then
        self.units[unit].name = name
        self.units[unit].englishClass = englishClass
        self.units[unit].class = UnitClass(unit)
        
        if (HealBot_Integrations_SuperWoW_Active or HealBot_Integrations_ClassicAPI_Active) and HealBot_GetUnitGUID then
            local guid = HealBot_GetUnitGUID(unit)
            if guid and guid ~= "0" and guid ~= "0x0000000000000000" then
                self.unitGUIDs[unit] = guid
                self.guidUnits[guid] = unit
            end
        end
        return true -- Identity changed
    end
    return false
end

-- HealBot_Model:GetUnitByGUID: Internal utility: HealBot_Model:GetUnitByGUID
function HealBot_Model:GetUnitByGUID(guid)
    if not guid then return nil end
    return self.guidUnits[guid]
end

-- HealBot_Model:GetUnitIDByName: Looks up a group unit token by player name.
function HealBot_Model:GetUnitIDByName(name)
    if not name then return nil end
    for unit, data in pairs(self.units) do
        if data.name == name then return unit end
    end
    return nil
end

-- HealBot_Model:PreserveStateByGUID: Preserves icon and debuff state when group indices shift during combat.
function HealBot_Model:PreserveStateByGUID()
    if not (HealBot_Integrations_SuperWoW_Active or HealBot_Integrations_ClassicAPI_Active) or not HealBot_GetUnitGUID then return end
    
    local oldGUIDs = {}
    for unit, guid in pairs(self.unitGUIDs) do
        if string.find(unit, "^party") or string.find(unit, "^raid") or unit == "player" or unit == "pet" then
            oldGUIDs[unit] = guid
        end
    end
    
    local newUnitForGUID = {}
    -- Scan the new roster
    for _, unit in ipairs(self.partyMembers) do
        local guid = HealBot_GetUnitGUID(unit)
        if guid and guid ~= "0" and guid ~= "0x0000000000000000" then 
            newUnitForGUID[guid] = unit 
            self.unitGUIDs[unit] = guid
            self.guidUnits[guid] = unit
        end
    end
    for _, unit in ipairs(self.raidMembers) do
        local guid = HealBot_GetUnitGUID(unit)
        if guid and guid ~= "0" and guid ~= "0x0000000000000000" then 
            newUnitForGUID[guid] = unit 
            self.unitGUIDs[unit] = guid
            self.guidUnits[guid] = unit
        end
    end
    
    local stateSwaps = {}
    local iconSwaps = {}
    local missingBuffSwaps = {}
    local debuffSwaps = {}
    
    for oldUnit, guid in pairs(oldGUIDs) do
        local newUnit = newUnitForGUID[guid]
        if newUnit and newUnit ~= oldUnit then
            stateSwaps[newUnit] = self.units[oldUnit]
            
            -- Preserve external global tables if they exist
            if HealBot_UnitIcons and HealBot_UnitIcons[oldUnit] then
                iconSwaps[newUnit] = HealBot_UnitIcons[oldUnit]
            end
            if HealBot_MissingBuffs and HealBot_MissingBuffs[oldUnit] ~= nil then
                missingBuffSwaps[newUnit] = HealBot_MissingBuffs[oldUnit]
            end
            if HealBot_UnitDebuff and HealBot_UnitDebuff[oldUnit] ~= nil then
                debuffSwaps[newUnit] = HealBot_UnitDebuff[oldUnit]
            end
        end
    end
    
    for targetUnit, stateData in pairs(stateSwaps) do
        -- Deep copy to prevent memory aliasing
        self.units[targetUnit] = {}
        for k, v in pairs(stateData) do
            self.units[targetUnit][k] = v
        end
        self.units[targetUnit].icons = {}

        if HealBot_UnitIcons and iconSwaps[targetUnit] then
            if not HealBot_UnitIcons[targetUnit] then HealBot_UnitIcons[targetUnit] = {} end
            for j=1, 10 do
                HealBot_UnitIcons[targetUnit][j] = iconSwaps[targetUnit][j]
            end
        end
        if HealBot_MissingBuffs then
            HealBot_MissingBuffs[targetUnit] = missingBuffSwaps[targetUnit]
        end
        if HealBot_UnitDebuff then
            HealBot_UnitDebuff[targetUnit] = debuffSwaps[targetUnit]
        end
    end
end

-- Updates health/maxHealth values. Returns true if changed.
function HealBot_Model:UpdateUnitHealth(unit)
    if not self.units[unit] then return false end
    
    local oldHealth = self.units[unit].health
    local oldMax = self.units[unit].maxHealth
    
    local currentHealth = UnitHealth(unit)
    local maxHealth = UnitHealthMax(unit)
    
    if oldHealth ~= currentHealth or oldMax ~= maxHealth then
        self.units[unit].health = currentHealth
        self.units[unit].maxHealth = maxHealth
        return true -- Value changed
    end
    
    return false
end

-- Updates power values (mana, rage, energy). Returns true if changed.
function HealBot_Model:UpdateUnitPower(unit)
    if not self.units[unit] then return false end
    
    local oldMana = self.units[unit].mana
    local oldMax = self.units[unit].maxMana
    local oldType = self.units[unit].powerType
    
    local currentMana = UnitMana(unit)
    local maxMana = UnitManaMax(unit)
    local powerType = UnitPowerType(unit)
    
    if oldMana ~= currentMana or oldMax ~= maxMana or oldType ~= powerType then
        self.units[unit].mana = currentMana
        self.units[unit].maxMana = maxMana
        self.units[unit].powerType = powerType
        return true -- Value changed
    end
    
    return false
end

-- Updates status flags (Dead, Ghost, Offline). Returns true if changed.
function HealBot_Model:UpdateUnitStatus(unit)
    if not self.units[unit] then return false end
    
    local oldDead = self.units[unit].isDead
    local oldGhost = self.units[unit].isGhost
    local oldConn = self.units[unit].isConnected
    
    local isDead = UnitIsDead(unit)
    local isGhost = UnitIsGhost(unit)
    local isConnected = UnitIsConnected(unit)
    
    -- Note: Vanilla API for UnitIsConnected sometimes returns nil instead of false
    if isConnected == nil then isConnected = false end
    if isDead == nil then isDead = false end
    if isGhost == nil then isGhost = false end
    
    if oldDead ~= isDead or oldGhost ~= isGhost or oldConn ~= isConnected then
        self.units[unit].isDead = isDead
        self.units[unit].isGhost = isGhost
        self.units[unit].isConnected = isConnected
        return true -- Value changed
    end
    
    return false
end

-- Updates incoming heals. Returns true if changed.
function HealBot_Model:UpdateIncomingHeal(unit, amount)
    if not self.units[unit] then return false end
    
    if self.units[unit].incomingHeal ~= amount then
        self.units[unit].incomingHeal = amount
        return true
    end
    return false
end

-- Manually mark auras as changed. 
function HealBot_Model:MarkAuraChanged(unit)
    -- We don't cache all auras in the model natively because it's too expensive
    -- to poll every buff/debuff. The controller tells the model an aura changed,
    -- and the view will resolve it if the unit is rendered.
    return true
end

-- Force a full refresh of a unit's API data
function HealBot_Model:RefreshUnit(unit)
    self:UpdateUnitIdentity(unit)
    self:UpdateUnitHealth(unit)
    self:UpdateUnitPower(unit)
    self:UpdateUnitStatus(unit)
    
    -- Force observers to render the initial state
    self:NotifyObservers("UNIT_HEALTH_CHANGED", unit)
    self:NotifyObservers("UNIT_POWER_CHANGED", unit)
end

-- Initialize the model state
HealBot_Model:Initialize()