Coroutine.ttslua

---@class ge_tts__Coroutine
local Coroutine = {}

---@param co thread
---@param onError nil | fun(message: string): void
local function resumeWithErrorHandling(co, onError)
    local result, message = coroutine.resume(co)

    if not result then
        if onError then
            (--[[---@not nil]] onError)(message)
        else
            error(message)
        end
    end
end

--- Yields from the current coroutine. Resumes once a condition is met or an optional timeout is reached.
---@overload fun(condition: fun(): boolean): true
---@overload fun(condition: (fun(): boolean), timeout: number): boolean
---@param condition fun(): boolean @Return true when the current coroutine should be resumed.
---@param timeout nil | number @Timeout in seconds (optional).
---@param onError nil | fun(message: string): void @A handler for any errors raised by the current coroutine after it has been resumed.
---@return boolean @True if the condition was met, or false if the (optional) timeout was reached.
function Coroutine.yieldCondition(condition, timeout, onError)
    local co = coroutine.running()

    ---@type nil | boolean
    local conditionMet

    local resume = function()
        conditionMet = true
        resumeWithErrorHandling(co, onError)
    end

    if timeout then
        Wait.condition(resume, condition, --[[---@not nil]] timeout, function()
            conditionMet = false
            resumeWithErrorHandling(co, onError)
        end)
    else
        Wait.condition(resume, condition)
    end

    coroutine.yield()

    if conditionMet == nil then
        error("Coroutine.yieldCondition(): attempt to resume before Wait was completed!")
    end

    return --[[---@not nil]] conditionMet
end

--- Yields from the current coroutine, which will later be resumed after the specified number of frames have passed.
---@overload fun(frames: number): void
---@param frames number
---@param onError nil | fun(message: string): void @A handler for any errors raised by the current coroutine after it has been resumed.
function Coroutine.yieldFrames(frames, onError)
    local co = coroutine.running()

    ---@type boolean
    local done

    Wait.frames(function()
        done = true
        resumeWithErrorHandling(co, onError)
    end, frames)

    coroutine.yield()

    if not done then
        error("Coroutine.yieldFrames(): attempt to resume before Wait was completed!")
    end
end

--- Yields from the current coroutine, which will later be resumed after the specified number of seconds have passed.
---@overload fun(seconds: number): void
---@param seconds number
---@param onError nil | fun(message: string): void @A handler for any errors raised by the current coroutine after it has been resumed.
function Coroutine.yieldSeconds(seconds, onError)
    local co = coroutine.running()

    ---@type boolean
    local done

    Wait.time(function()
        done = true
        resumeWithErrorHandling(co, onError)
    end, seconds)

    coroutine.yield()

    if not done then
        error("Coroutine.yieldSeconds(): attempt to resume before Wait was completed!")
    end
end

--- Creates a co-routine from the specified function, and immediately starts it.
---@param func fun
---@return boolean, any...
function Coroutine.start(func)
    return coroutine.resume(coroutine.create(func))
end

return Coroutine