--[[---------------------------------------------------------------------------
  Grichelde
  Copyright 2020 Teilzeit-Jedi <tj@teilzeit-jedi.de>

  based on Misspelled developed by Nathan Pieper - nrpieper (@) gmail (dot) com

  This code freely distributed for your use in any GPL compliant project.
  See conditions in the LICENSE file attached.

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

--------------------------------------------------------------------------]] --

local AddonName, AddonTable = ...

local Grichelde = LibStub("AceAddon-3.0"):NewAddon("Grichelde", "AceEvent-3.0", "AceHook-3.0")
Grichelde.version = GetAddOnMetadata(AddonName, "Version")
Grichelde.build = GetAddOnMetadata(AddonName, "X-Build") or "UNKNOWN"

local L = LibStub("AceLocale-3.0"):GetLocale("Grichelde", true)

local Grichelde_Debug = false

-- faster function lookups by mapping to local refs
local string_find = string.find
local string_gsub = string.gsub
local string_len = string.len
local string_rep = string.rep
local string_sub = string.sub
local strtrim = strtrim
local strmatch = strmatch
local tostring = tostring
local tInsert = table.insert
local tContains = tContains
local pairs = pairs
local ipairs = ipairs

local Grichelde_Hooks = {}

--local Grichelde_ChatTypes = { "SAY", "EMOTE", "YELL", "PARTY", "GUILD", "OFFICER", "RAID", "RAID_WARNING", "INSTANCE_CHAT", "BATTLEGROUND", "WHISPER" }
local Grichelde_ChatTypes = { "SAY", "EMOTE", "YELL", "PARTY", "GUILD" }
local Grichelde_ChatCommands = { "/s", "/e", "/me", "/y", "/p", "/pl", "/g", "/o", "/raid", "/rl", "/rw", "/i", "bg", "/w", "/r", "/tt" }

-- do not replace these patterns
local Grichelde_IgnorePatterns = {
    "|[Cc]%x%x%x%x%x%x%x%x.-|r",    -- colored items (or links)
    "|H.-|h",                       -- item links (http://www.wowwiki.com/ItemLink)
    "|T.-|t",                       -- textures
    "|n",                           -- newline
    "{rt[1-8]}",                    -- rumbered raid target icons
    "{Star}",                       -- named raid target icon 1
    "{Circle}",                     -- named raid target icon 2
    "{Coin}",                       -- named raid target icon 2
    "{Diamond}",                    -- named raid target icon 3
    "{Triangle}",                   -- named raid target icon 4
    "{Moon}",                       -- named raid target icon 5
    "{Square}",                     -- named raid target icon 6
    "{Cross}",                      -- named raid target icon 7
    "{X}",                          -- named raid target icon 7
    "{Skull}"                       -- named raid target icon 8
}

function Grichelde:OnInitialize()
    -- Build Interface Options window
    --self:CreateInterfaceOptions()

    -- Watch for WIM and Prat to Load, then integrate
    self:RegisterEvent("ADDON_LOADED", "HookIntoForOtherChatAddons")
end

function Grichelde:OnEnable()
    -- Hook in before message is sent to replace all character occurrences where replacements have been defined in the options
    self:RawHook("SendChatMessage", true)

    if (Misspelled) then
        print("Misspelled detected, Grichelde will have any messsage being cleansed")
    end

    -- tell the world we are listening
    print(L.AddonLoaded)
end

function Grichelde:OnDisable()
    self:Unhook("SendChatMessage")
end

--- @param event string
--- @param addonName string
function Grichelde:HookIntoForOtherChatAddons(event, addonName)
    if event == "ADDON_LOADED" then
        if addonName == "WIM" then
            WIM.RegisterWidgetTrigger("msg_box", "whisper,chat,w2w", "OnEnterPressed", Grichelde.EditBox_OnEnterPressed)

            -- If available use the WIM API
            if (WIM.RegisterPreSendFilterText) then -- avoid error if WIM not up to date.
                WIM.RegisterPreSendFilterText(function(text)
                    return Grichelde:CheckAndReplace(text)
                end)
            else
                -- WIM sends its chat messages via the API ChatThrottleLib, which itself hooks the default SendChatMessage api
                -- many times before Grichelde will. ChatThrottleLib might potentially load before Grichelde, so we just hook
                -- into ChatThrottleLib to be on the safe side.

                if (ChatThrottleLib) then
                    Grichelde_Hooks["ChatThrottleLib"] = ChatThrottleLib.SendChatMessage

                    function ChatThrottleLib:SendChatMessage(prio, prefix, text, ...)
                        Grichelde:DebugPrint("ChatThrottleLib:SendChatMessage : Hook called")
                        local replacedText = Grichelde:CheckAndReplace(text)
                        return Grichelde_Hooks["ChatThrottleLib"](ChatThrottleLib, prio, prefix, replacedText, ...)
                    end
                end
            end
        end
    end
end

--- Before af chat message is sent, check if replacement is required and replace the text accordingly.
--- @param message string
--- @param type string
--- @param language string
--- @param channel string
function Grichelde:SendChatMessage(message, type, language, channel, ...)
    local replacedText = self:CheckAndReplace(message, type)

    self:DebugPrint("SendChatMessage : replacedText: " .. replacedText)

    -- Send text in chunks if length exceeds 255 bytes after replacement
    local chunks = self:SplitText(replacedText)
    self:DebugPrint("SendChatMessage : #chunks: " .. #chunks)

    for _, chunk in ipairs(chunks) do
        self.hooks["SendChatMessage"](chunk, type, language, channel, ...);
    end
end

function Grichelde:CheckAndReplace(message, type)
    local text = message
    if (Misspelled) then
        self:DebugPrint("Misspelled detected: cleansing message")
        text = Misspelled:RemoveHighlighting(text)
    end
    text = strtrim(text)

    if (self:CheckReplacement(text, type)) then
        text = self:ReplaceText(text)
    end
    return text
end

function Grichelde:CheckReplacement(text, type)
    -- todo: globally disabled?

    -- check type
    if (not tContains(Grichelde_ChatTypes, type)) then
        self:DebugPrint("CheckReplacement : skip channel type")
        return false
    end

    -- don't replace slash commands except chat related commands
    if string_sub(text, 1, 1) == "/" then
        local firstWord, _ = self:SplitOnFirstMatch(text)
        if (firstWord == nil or not tContains(Grichelde_ChatCommands, firstWord)) then
            self:DebugPrint("CheckReplacement : ignore slash command")
            return false
        end
    end

    -- in any other case
    return true
end

--- Checks if the text starts with a preversable ignore pattern, such as itemLinks, textures or raid target icons
--- and returns the end location of the match, or 0 if no pattern was found
--- @param text string
--- @return number
function Grichelde:CheckForPreversableText(text)
    self:DebugPrint("CheckForPreversableText : text is " .. text)
    -- Calling find on ever pattern might be inefficient but its way less code.
    for _, pattern in ipairs(Grichelde_IgnorePatterns) do
        local pos1, pos2 = string_find(text, pattern)
        if pos1 == 1 and pos2 ~= nil then
            self:DebugPrint("CheckForPreversableText : Found ignore pattern " .. pattern .. " at (" .. pos1 .. "," .. pos2 .. ")")
            return pos2
        end
    end
    self:DebugPrint("CheckForPreversableText : no ignore pattern found")
    return 0
end

--- Replaces all character occurrences for which replacements have been defined in the options,
--- while preserving any itemLinks or textures. (http://www.wowwiki.com/ItemLink)
--- @param text string
--- @return string
function Grichelde:ReplaceText(text)
    local finalText = ""
    local newText = text

    -- don't replace non-chat related slash commands
    local firstWord, line = self:SplitOnFirstMatch(text)
    if (firstWord ~= nil and tContains(Grichelde_ChatCommands, firstWord)) then
        self:DebugPrint("ReplaceText : Found slash command " .. (firstWord + "") )
        -- skip chat slash command
        finalText = finalText .. firstWord .. ' '
        newText = line
    end

    local current = 1
    local lastStart = 1

    while current <= string_len(newText) do
        local currentChar = string_sub(newText, current, current)
        self:DebugPrint("current/char : " .. current .. "," .. currentChar)

        if currentChar ~= '|' and currentChar ~= '{' then
            current = current + 1
        else

            -- lookahead-check for itemLinks, textures and raid target icons
            local textAhead = string_sub(newText, current)
            local posEnd = self:CheckForPreversableText(textAhead)
            if posEnd > 0 then
                self:DebugPrint("ReplaceText : Found an ignore pattern")

                local textBehind = string_sub(newText, lastStart, current - 1)
                local replacement = self:ReplaceCharacters(textBehind)
                local preservedText = string_sub(textAhead, 1, posEnd)

                finalText = finalText .. replacement .. preservedText
                current = current + posEnd
                lastStart = current
                self:DebugPrint("ReplaceText : restarting at " .. lastStart)
            else
                -- no corresponding end was found to start pattern, continue loop with next char
                current = current + 1
            end
        end
    end

    -- cleanup remaining text to the end
    local remainingText = string_sub(newText, lastStart)
    local replacement = self:ReplaceCharacters(remainingText)
    finalText = finalText .. replacement

    self:DebugPrint("ReplaceText : replaced \"" .. text .. "\"")
    self:DebugPrint("ReplaceText : with         \"" .. finalText .. "\"")
    return finalText
end

--- Replaces all character occurrences for which replacements have been defined in the options
--- @param text string
--- @return string
function Grichelde:ReplaceCharacters(text)
    -- todo: read from options
    -- todo: case (in)sensitivity
    local replacement = text
    replacement = string_gsub(replacement, "s", "ch")
    replacement = string_gsub(replacement, "S", "Ch")
    replacement = string_gsub(replacement, "t", "k")
    replacement = string_gsub(replacement, "T", "K")
    self:DebugPrint("ReplaceCharacters : replaced \"" .. text .. "\" with \"" .. replacement .. "\"")
    return replacement
end

--- Splits a long text in longest possible chunks of <= 255 length, split at last available space
--- @param text string
--- @return table
function Grichelde:SplitText(text)
    local chunks = {}
    local splitText = text
    local textSize = string_len(splitText)

    while textSize > 255 do
        local chunk = string_sub(splitText, 1, 255)
        local remaining = ""

        -- special case: if space is the start of the next chunk, don't split this chunk
        if string_sub(splitText, 256, 256) ~= ' ' then
            -- split at last space, don't assign directly as nil might be returned
            local left, right = self:SplitOnLastMatch(chunk)
            if left ~= nil then
                chunk = left
            end
            if right ~= nil then
                remaining = right
            end
        end

        self:DebugPrint("SplitText : chunk: " .. chunk )

        tInsert(chunks, chunk)
        splitText = remaining .. string_sub(splitText, 256)
        textSize = string_len(splitText)
    end

    -- pickup remaining text < 255
    self:DebugPrint("SplitText : last chunk: " .. splitText)
    tInsert(chunks, splitText)

    return chunks
end

-- split first word of a text line
function Grichelde:SplitOnFirstMatch(text, start)
    self:DebugPrint("SplitOnFirstMatch : text: " .. text .. ", start: " .. self:EmptyIfNil(start))
    local pos = 1
    if start ~= nil then pos = start end
    local left, right = strmatch(text, "^.- .+", pos)
    self:DebugPrint("SplitOnFirstMatch : left: " .. self:EmptyIfNil(left) .. ", right: " .. self:EmptyIfNil(right))
    return left, right
end

function Grichelde:SplitOnLastMatch(text, start)
    self:DebugPrint("SplitOnLastMatch : text: " .. text .. ", start: " .. self:EmptyIfNil(start))
    local pos = 1
    if start ~= nil then pos = start end
    local left, right = strmatch(text, ".+ .-$", pos)
    self:DebugPrint("SplitOnLastMatch : left: " .. self:EmptyIfNil(left) .. ", right: " .. self:EmptyIfNil(right))
    return left, right
end

function Grichelde:DebugPrint(message)
    if (Grichelde_Debug) then
        print(GRAY_FONT_COLOR_CODE .. "Grichelde:" .. FONT_COLOR_CODE_CLOSE .. " " .. message)
    end
end

function Grichelde:EmptyIfNil(value)
    if value == nil then return "" end
    return tostring(value)
end

function Grichelde:tprint(t, indent, done)
    -- in case we run it standalone
    local Note = Note or print
--  local Tell = Tell or io.write

    -- show strings differently to distinguish them from numbers
    local function show(val)
        if type(val) == "string" then
            return '"' .. val .. '"'
        else
            return tostring(val)
        end
    end

    -- entry point here
    done = done or {}
    indent = indent or 0
    for key, value in pairs(t) do
        print(string_rep(" ", indent)) -- indent it
        if type(value) == "table" and not done[value] then
            done[value] = true
            Note(show(key), ":");
            self:tprint(value, indent + 2, done)
        else
            print(show(key), "=")
            print(show(value))
        end
    end
end