// tss.ts
type PseudoKeys = ["hover"|"before"|"after"] | ["hover", "after"|"before"];
type ValueSignature = (...args:any[])=>string
type EnumDefinition<Signature> = [property:string, options:Record<string, string>, values?:Signature];
type EnumBlock<Signature> = Record<string, EnumDefinition<Signature>>;
type RecursiveObject<Sig extends ValueSignature, Obj extends EnumBlock<Sig>> =
{
  [F in keyof Obj]: Obj[F][2] extends Sig ? ((...args:Parameters<Obj[F][2]>)=> RecursiveObject<Sig, Obj>&((...args:PseudoKeys)=>RecursiveObject<Sig, Obj>)&Array<RecursiveObject<Sig, Obj>>)&{
    [E in keyof Obj[F][1]]:RecursiveObject<Sig, Obj>&((...args:PseudoKeys)=>RecursiveObject<Sig, Obj>)&Array<RecursiveObject<Sig, Obj>>
  } :
  {
    [E in keyof Obj[F][1]]:RecursiveObject<Sig, Obj>&((...args:PseudoKeys)=>RecursiveObject<Sig, Obj>)&Array<RecursiveObject<Sig, Obj>>
  }
}

function Block<Signature extends ValueSignature, Fields extends EnumBlock<Signature>>(options:Fields):()=>RecursiveObject<Signature, Fields>
{
  return ()=>{

    let pseudo = false;
    let query = false;
    const list = [];
    let fieldLookup = {};

    const proxyOuter = new Proxy(
      function(...args)
      {
        // OUTER context called as function:

        if(args.length) // pseudo elements are being declared, capture and return the OUTER context
        {
          list.push(`${(pseudo||query) ? "}" : ""} &:${args.join("::")}{`);
          pseudo = true;
          query = false;
          return proxyOuter;
        }
        else // css dump requested:
        {
          pseudo && list.push("}");
          query && list.push("}");
          pseudo = false;
          query = false;
          return list;
        }
      },
      {
        get(_target, propName)
        {
          // OUTER context property access:

          if(parseInt(propName)) // if a number was used as a property, treat that as a mobile-first media query in px units, and return the OUTER context
          {
            list.push(`${(query) ? "}" : ""} @media(min-width:${propName}px){`);
            query = true;
            return proxyOuter;
          }

          // a css property alias was accessed, look up the mapped css property name from the declaration array, push that, and return the OUTER context
          fieldLookup = options[propName];
          if(fieldLookup)
          {
            list.push(fieldLookup[0]);
          }
          return proxyInner;
        }
      }
    );

    const proxyInner = new Proxy(
      function(...args)
      {
        // INNER context called as function

        // capture the evalued dynamic values and return the OUTER context
        list.push(`:${fieldLookup[2](...args)};`);
        return proxyOuter;
      },
      {
        get(_target, valName)
        {
          // INNER context property access

          try // capture the mapped css value and return the OUTER context
          {
            list.push(`:${fieldLookup[1][valName]};`);
            return proxyOuter;
          }
          catch(_e)
          {
            console.warn("someone is trying to stringify a style proxy");
            return ()=>"[StyleProxy]";
          }
        }
      }
    );
    return proxyOuter;
  }
}

type Measure = "px" | "em" | "rem" | "vh" | "vw" | "%"; 
type UnitString = `${number}${Measure}`;

const funcUnitSingle = (amount:UnitString)=>amount
const funcUnitTRBL=<T = UnitString>(...args:[t:T, r?:T, b?:T, l?:T])=>args.join(" ")
const UnitAuto = {Auto:"auto"};

const styles = Block(
{
      Pos:["position",   { Abs:"absolute", Rel:"relative", Fix:"fixed", Pin:"sticky", No:"static" }],
      Dis:["display",    { Flex:"flex", Grid:"grid", None:"none", Block:"block", InlineBlock:"inline-block" }],
      Box:["box-sizing", { Border:"border-box", Content:"content-box" }],

      T:["top",    UnitAuto, funcUnitSingle],
      R:["right",  UnitAuto, funcUnitSingle],
      B:["bottom", UnitAuto, funcUnitSingle],
      L:["left",   UnitAuto, funcUnitSingle],

      Pad: ["padding",        {}, funcUnitTRBL  ],
      PadT:["padding-top",    {}, funcUnitSingle],
      PadR:["padding-right",  {}, funcUnitSingle],
      PadB:["padding-bottom", {}, funcUnitSingle],
      PadL:["padding-left",   {}, funcUnitSingle],

      Mar: ["margin",        UnitAuto, funcUnitTRBL<UnitString|"auto">  ],
      MarT:["margin-top",    UnitAuto, funcUnitSingle],
      MarR:["margin-right",  UnitAuto, funcUnitSingle],
      MarB:["margin-bottom", UnitAuto, funcUnitSingle],
      MarL:["margin-left",   UnitAuto, funcUnitSingle]
}
);

const masterSheet = {};

const SheetId = {
  index:-1,
  getId()
  {
    this.index++;
    return this.index;
  }
};

export function Sheet<UserClasses extends Record<string, (this:ReturnType<typeof styles>, css:ReturnType<typeof styles>)=>void >>(userClasses:UserClasses):{[Class in keyof UserClasses]:string}
{
  const hash = SheetId.getId();

  const writer = globalThis["document"]
    ? (selector, declaration)=>
    {
      const styleBlock = document.createElement("style");
      styleBlock.innerText = "."+selector+declaration;
      document.head.insertAdjacentElement("beforeend", styleBlock)
    }
    : (selector, declaration)=>{masterSheet[selector] = declaration};

  return new Proxy(function(){}, {get(_target, className){

    const lookup = userClasses[className];
    if(typeof lookup == "function")
    {
      const skewer = styles();
      lookup.call(skewer, skewer);
      const name = `${className}_${hash}`;
      writer(name, `{ ${skewer().join("")} }`)
      userClasses[className] = name;
      return name;
    }
    else
    {
      return lookup;
    }
  }});
}

export function Divulge()
{
  return masterSheet;
}