// ── New Project modal & templates ──────────────────────────────────────────
//
// Each template is a function that receives the project name and builds the
// initial workspace (blocks, variables, connections, libraries) in place.
//
// Load order: loaded after persist.js, before app.js
// Depends on: dom.js ($id), helpers.js, draw.js, wcblock.js, blocks-*.js,
//             wcprogram.js, persist.js, lib-loader.js

/**
 * Removes all user-created blocks, connections, library tabs and panes,
 * resetting flow arrays and LOADED_LIBS. Used by templates (new project) and
 * persist.js (load workspace, with keepStorage:true to preserve localStorage).
 * @param {{ keepStorage?: boolean }} [opts]
 */
function _clearWorkspace(opts = {}) {
  const { keepStorage } = opts;
  const conn = $id("connections");
  if (conn) {
    for (const p of conn.querySelectorAll("path.flow, path.flow-data")) p.remove();
  }
  for (const block of document.querySelectorAll("[data-block]")) {
    if (block.wcForeFlow) block.wcForeFlow = [];
    if (block.wcNextFlow) block.wcNextFlow = [];
  }
  const prog = $id("main-program");
  if (prog) {
    for (const block of [...prog.children]) {
      if (block.id !== "main-start" && block.id !== "main-end") block.remove();
    }
  }
  const dataArea = $id("data-area");
  if (dataArea) {
    for (const block of [...dataArea.querySelectorAll("[data-block]")]) block.remove();
  }
  const varArea = $id("variable-area");
  if (varArea) {
    for (const block of [...varArea.querySelectorAll("[data-block]")]) block.remove();
  }
  const libTabBar = document.querySelector(".lib-tab-bar");
  if (libTabBar) libTabBar.innerHTML = "";
  for (const pane of document.querySelectorAll(".lib-pane")) pane.remove();
  for (const tab of document.querySelectorAll(".lib-tab")) tab.remove();
  LOADED_LIBS.clear();
  if (!keepStorage) localStorage.removeItem(STORAGE_KEY);
}

function _pos(el, left, top) {
  el.style.left = left + "px";
  el.style.top = top + "px";
}

function _placeBelow(prev, block, gap = 16) {
  block.style.top = (prev.offsetTop + prev.offsetHeight + gap) + "px";
}

function _createAssign(prog, targetId, value) {
  const el = prog.newNode("wc-assign");
  if (!el) return null;
  el.style.left = "50px";
  el._el.target.value = targetId;
  el._el.value.value = String(value);
  el._syncType();
  el._updateValueVisibility();
  return el;
}

function _createVarRef(prog, varId) {
  const el = prog.newVarRefNode();
  if (!el) return null;
  el.style.left = "50px";
  el._el.select.value = varId;
  const target = varId ? $id(varId) : null;
  const hook = el.querySelector(".hook-out");
  if (hook) hook.dataset.type = target ? (target.dataType === "vector" ? "scalar" : target.dataType) : "scalar";
  return el;
}

function _createProcCall(prog, qname, resultName) {
  const el = prog.newProcCallNode();
  if (!el) return null;
  el.style.left = "50px";
  if (el._el.nameInput) el._el.nameInput.value = resultName || "";
  el.setProcedure(qname);
  return el;
}

function _createScalarVar(prog, name) {
  const el = prog.newScalarNode();
  if (!el) return null;
  el.style.left = "700px";
  const nameEl = el.querySelector(".var-name");
  if (nameEl) nameEl.value = name;
  return el;
}

function _createBooleanVar(prog, name, value) {
  const el = prog.newBooleanNode();
  if (!el) return null;
  el.style.left = "700px";
  const nameEl = el.querySelector(".var-name");
  if (nameEl) nameEl.value = name;
  const valEl = el.querySelector(".var-value");
  if (valEl) valEl.value = value || "false";
  return el;
}

async function _loadLib(libId) {
  const index = await loadLibraryIndex();
  const entry = index.find(e => e.id === libId);
  if (entry) await loadLibrary(libId);
}

const TEMPLATES = {};

TEMPLATES.console = {
  name: "Console Program",
  icon: "\u25A0",
  desc: "Basic C program with stdio",
  async create(prog, projectName) {
    _clearWorkspace();
    await _loadLib("stdio");
    refreshAll();

    const start = $id("main-start");
    const end = $id("main-end");
    _pos(start, 50, 50);

    const printfCall = _createProcCall(prog, "stdio/printf", "");
    _placeBelow(start, printfCall);
    if (printfCall) {
      const arg = printfCall.querySelector(".proccall-inputs .proccall-arg-input");
      if (arg) arg.value = '"Hello, World!\\n"';
    }

    _pos(end, 50, printfCall.offsetTop + printfCall.offsetHeight + 16);

    if (start && end && printfCall) {
      _linkFlow(start, ".hook", printfCall, ".hook-in");
      _linkFlow(printfCall, ".hook-out", end, ".hook");
    }
  }
};

TEMPLATES["sdl3-triangle"] = {
  name: "SDL3 Hello Triangle",
  icon: "\u25B3",
  desc: "SDL3 + OpenGL colored triangle",
  async create(prog, projectName) {
    _clearWorkspace();
    await _loadLib("sdl3");
    await _loadLib("gl");
    refreshAll();

    const start = $id("main-start");
    const end = $id("main-end");
    _pos(start, 50, 50);

    /* Variables column (x=700) */
    let varTop = start;
    function varBelow(block) { _placeBelow(varTop, block); varTop = block; }

    const varRunning = _createBooleanVar(prog, "running", "true");       varBelow(varRunning);
    const varWindow = _createScalarVar(prog, "window");                  varBelow(varWindow);
    const varRenderer = _createScalarVar(prog, "renderer");               varBelow(varRenderer);
    const varVS = _createScalarVar(prog, "vs");                          varBelow(varVS);
    const varFS = _createScalarVar(prog, "fs");                          varBelow(varFS);
    const varProgram = _createScalarVar(prog, "program");                 varBelow(varProgram);
    const varVAO = _createScalarVar(prog, "vao");                        varBelow(varVAO);

    /* ── Initialisation chain (x=50) — each block placed below the previous ── */
    let prev = start;
    function algBelow(block) { _placeBelow(prev, block); prev = block; }

    const initCall = _createProcCall(prog, "sdl3/SDL_Init", "ret");      algBelow(initCall);
    if (initCall) {
      const inputs = initCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "SDL_INIT_VIDEO";
    }

    const setMetaCall = _createProcCall(prog, "sdl3/SDL_SetAppMetadata", "");  algBelow(setMetaCall);
    if (setMetaCall) {
      const inputs = setMetaCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = '"' + projectName + '"';
      if (inputs[1]) inputs[1].value = '"1.0"';
      if (inputs[2]) inputs[2].value = '"com.example.triangle"';
    }

    const winCall = _createProcCall(prog, "sdl3/SDL_CreateWindow", "window");  algBelow(winCall);
    if (winCall) {
      const inputs = winCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = '"Hello Triangle"';
      if (inputs[1]) inputs[1].value = "640";
      if (inputs[2]) inputs[2].value = "480";
      if (inputs[3]) inputs[3].value = "0";
    }

    const renCall = _createProcCall(prog, "sdl3/SDL_CreateRenderer", "renderer");  algBelow(renCall);
    if (renCall) {
      const inputs = renCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "window";
      if (inputs[1]) inputs[1].value = "NULL";
    }

    const vsAssign = _createAssign(prog, varVS ? varVS.id : "", '"#version 330\\nlayout(location=0) in vec3 pos; void main(){gl_Position=vec4(pos,1);}"');  algBelow(vsAssign);
    const fsAssign = _createAssign(prog, varFS ? varFS.id : "", '"#version 330\\nout vec4 c; void main(){c=vec4(1,0,0,1);}"');  algBelow(fsAssign);

    const vsCreateCall = _createProcCall(prog, "gl/glCreateShader", "vs");  algBelow(vsCreateCall);
    if (vsCreateCall) {
      const inputs = vsCreateCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "GL_VERTEX_SHADER";
    }

    const vsSrcCall = _createProcCall(prog, "gl/glShaderSource", "");  algBelow(vsSrcCall);
    if (vsSrcCall) {
      const inputs = vsSrcCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "vs";
      if (inputs[1]) inputs[1].value = "1";
      if (inputs[2]) inputs[2].value = "vs";
    }

    const vsCompCall = _createProcCall(prog, "gl/glCompileShader", "");  algBelow(vsCompCall);
    if (vsCompCall) {
      const inputs = vsCompCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "vs";
    }

    const fsCreateCall = _createProcCall(prog, "gl/glCreateShader", "fs");  algBelow(fsCreateCall);
    if (fsCreateCall) {
      const inputs = fsCreateCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "GL_FRAGMENT_SHADER";
    }

    const fsSrcCall = _createProcCall(prog, "gl/glShaderSource", "");  algBelow(fsSrcCall);
    if (fsSrcCall) {
      const inputs = fsSrcCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "fs";
      if (inputs[1]) inputs[1].value = "1";
      if (inputs[2]) inputs[2].value = "fs";
    }

    const fsCompCall = _createProcCall(prog, "gl/glCompileShader", "");  algBelow(fsCompCall);
    if (fsCompCall) {
      const inputs = fsCompCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "fs";
    }

    const progCreate = _createProcCall(prog, "gl/glCreateProgram", "program");  algBelow(progCreate);
    const progAttach1 = _createProcCall(prog, "gl/glAttachShader", "");  algBelow(progAttach1);
    if (progAttach1) {
      const inputs = progAttach1.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "program";
      if (inputs[1]) inputs[1].value = "vs";
    }
    const progAttach2 = _createProcCall(prog, "gl/glAttachShader", "");  algBelow(progAttach2);
    if (progAttach2) {
      const inputs = progAttach2.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "program";
      if (inputs[1]) inputs[1].value = "fs";
    }
    const progLink = _createProcCall(prog, "gl/glLinkProgram", "");  algBelow(progLink);
    if (progLink) {
      const inputs = progLink.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "program";
    }

    const vaoGen = _createProcCall(prog, "gl/glGenVertexArrays", "vao");  algBelow(vaoGen);
    if (vaoGen) {
      const inputs = vaoGen.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "1";
    }
    const vaoBind = _createProcCall(prog, "gl/glBindVertexArray", "");  algBelow(vaoBind);
    if (vaoBind) {
      const inputs = vaoBind.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "vao";
    }

    const bufGen = _createProcCall(prog, "gl/glGenBuffers", "");  algBelow(bufGen);
    if (bufGen) {
      const inputs = bufGen.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "1";
    }
    const bufBind = _createProcCall(prog, "gl/glBindBuffer", "");  algBelow(bufBind);
    if (bufBind) {
      const inputs = bufBind.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "GL_ARRAY_BUFFER";
      if (inputs[1]) inputs[1].value = "vbo";
    }

    /* ── Main loop ── */
    const loopDec = prog.newDecisionNode();  loopDec.style.left = "50px";  algBelow(loopDec);
    const pollCall = _createProcCall(prog, "sdl3/SDL_PollEvent", "event");  algBelow(pollCall);
    if (pollCall) {
      const inputs = pollCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "event";
    }

    const checkEvent = prog.newDecisionNode();  checkEvent.style.left = "50px";  algBelow(checkEvent);
    const stopRunning = _createAssign(prog, varRunning ? varRunning.id : "", "false");  algBelow(stopRunning);
    const clearCall = _createProcCall(prog, "gl/glClear", "");  algBelow(clearCall);
    if (clearCall) {
      const inputs = clearCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "GL_COLOR_BUFFER_BIT";
    }
    const useProgCall = _createProcCall(prog, "gl/glUseProgram", "");  algBelow(useProgCall);
    if (useProgCall) {
      const inputs = useProgCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "program";
    }
    const drawCall = _createProcCall(prog, "gl/glDrawArrays", "");  algBelow(drawCall);
    if (drawCall) {
      const inputs = drawCall.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "GL_TRIANGLES";
      if (inputs[1]) inputs[1].value = "0";
      if (inputs[2]) inputs[2].value = "3";
    }

    const renClear = _createProcCall(prog, "sdl3/SDL_RenderClear", "");  algBelow(renClear);
    if (renClear) {
      const inputs = renClear.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "renderer";
    }
    const renPresent = _createProcCall(prog, "sdl3/SDL_RenderPresent", "");  algBelow(renPresent);
    if (renPresent) {
      const inputs = renPresent.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "renderer";
    }

    /* ── Cleanup (after loop body) ── */
    const renDestroy = _createProcCall(prog, "sdl3/SDL_DestroyRenderer", "");  algBelow(renDestroy);
    if (renDestroy) {
      const inputs = renDestroy.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "renderer";
    }
    const winDestroy = _createProcCall(prog, "sdl3/SDL_DestroyWindow", "");  algBelow(winDestroy);
    if (winDestroy) {
      const inputs = winDestroy.querySelectorAll(".proccall-inputs .proccall-arg-input");
      if (inputs[0]) inputs[0].value = "window";
    }
    const quitCall = _createProcCall(prog, "sdl3/SDL_Quit", "");  algBelow(quitCall);
    _pos(end, 50, prev.offsetTop + prev.offsetHeight + 16);

    /* ── Wire up flow connections ── */
    _linkFlow(start, ".hook", initCall, ".hook-in");
    if (initCall) _linkFlow(initCall, ".hook-out", setMetaCall, ".hook-in");
    if (setMetaCall) _linkFlow(setMetaCall, ".hook-out", winCall, ".hook-in");
    if (winCall) _linkFlow(winCall, ".hook-out", renCall, ".hook-in");
    if (renCall) _linkFlow(renCall, ".hook-out", vsAssign, "#hook-fore");
    if (vsAssign) _linkFlow(vsAssign, "#hook-next", fsAssign, "#hook-fore");
    if (fsAssign) _linkFlow(fsAssign, "#hook-next", vsCreateCall, ".hook-in");
    if (vsCreateCall) _linkFlow(vsCreateCall, ".hook-out", vsSrcCall, ".hook-in");
    if (vsSrcCall) _linkFlow(vsSrcCall, ".hook-out", vsCompCall, ".hook-in");
    if (vsCompCall) _linkFlow(vsCompCall, ".hook-out", fsCreateCall, ".hook-in");
    if (fsCreateCall) _linkFlow(fsCreateCall, ".hook-out", fsSrcCall, ".hook-in");
    if (fsSrcCall) _linkFlow(fsSrcCall, ".hook-out", fsCompCall, ".hook-in");
    if (fsCompCall) _linkFlow(fsCompCall, ".hook-out", progCreate, ".hook-in");
    if (progCreate) _linkFlow(progCreate, ".hook-out", progAttach1, ".hook-in");
    if (progAttach1) _linkFlow(progAttach1, ".hook-out", progAttach2, ".hook-in");
    if (progAttach2) _linkFlow(progAttach2, ".hook-out", progLink, ".hook-in");
    if (progLink) _linkFlow(progLink, ".hook-out", vaoGen, ".hook-in");
    if (vaoGen) _linkFlow(vaoGen, ".hook-out", vaoBind, ".hook-in");
    if (vaoBind) _linkFlow(vaoBind, ".hook-out", bufGen, ".hook-in");
    if (bufGen) _linkFlow(bufGen, ".hook-out", bufBind, ".hook-in");

    if (bufBind) _linkFlow(bufBind, ".hook-out", loopDec, "#hook-fore");
    if (loopDec) _linkFlow(loopDec, "#hook-out1", pollCall, ".hook-in");
    if (pollCall) _linkFlow(pollCall, ".hook-out", checkEvent, "#hook-fore");
    if (checkEvent) _linkFlow(checkEvent, "#hook-out1", stopRunning, ".hook-in");
    if (stopRunning) _linkFlow(stopRunning, "#hook-next", clearCall, ".hook-in");
    if (checkEvent) _linkFlow(checkEvent, "#hook-out0", clearCall, ".hook-in");
    if (clearCall) _linkFlow(clearCall, ".hook-out", useProgCall, ".hook-in");
    if (useProgCall) _linkFlow(useProgCall, ".hook-out", drawCall, ".hook-in");
    if (drawCall) _linkFlow(drawCall, ".hook-out", renClear, ".hook-in");
    if (renClear) _linkFlow(renClear, ".hook-out", renPresent, ".hook-in");

    if (loopDec) _linkFlow(loopDec, "#hook-out0", renDestroy, ".hook-in");
    if (renDestroy) _linkFlow(renDestroy, ".hook-out", winDestroy, ".hook-in");
    if (winDestroy) _linkFlow(winDestroy, ".hook-out", quitCall, ".hook-in");
    if (quitCall) _linkFlow(quitCall, ".hook-out", end, ".hook");
  }
};

function showNewProjectModal() {
  const overlay = $id("new-project-overlay");
  if (!overlay) return;
  const nameInput = $id("project-name");
  if (nameInput) nameInput.value = "Untitled";
  /* Reset to default template */
  _selectedTemplateId = "console";
  for (const c of document.querySelectorAll(".template-card")) c.classList.remove("selected");
  const def = document.querySelector('.template-card[data-template="console"]');
  if (def) def.classList.add("selected");
  overlay.style.display = "";
}

function hideNewProjectModal() {
  const overlay = $id("new-project-overlay");
  if (overlay) overlay.style.display = "none";
}

/* Expose for app.js */
window.TEMPLATES = TEMPLATES;
window.showNewProjectModal = showNewProjectModal;
window.hideNewProjectModal = hideNewProjectModal;

/* Wire up modal interactivity on DOMContentLoaded */
let _selectedTemplateId = "console";
document.addEventListener("DOMContentLoaded", () => {
  const overlay = $id("new-project-overlay");
  if (!overlay) return;
  const list = overlay.querySelector("#template-list");

  /* Template card selection via event delegation */
  if (list) {
    list.addEventListener("click", e => {
      const card = e.target.closest(".template-card");
      if (!card) return;
      for (const c of list.children) c.classList.remove("selected");
      card.classList.add("selected");
      _selectedTemplateId = card.dataset.template;
    });
  }

  /* Cancel button */
  const cancelBtn = overlay.querySelector(".modal-cancel");
  if (cancelBtn) cancelBtn.addEventListener("click", hideNewProjectModal);

  /* Create button */
  const createBtn = overlay.querySelector(".modal-create");
  if (createBtn) {
    createBtn.addEventListener("click", async () => {
      const nameInput = $id("project-name");
      const name = nameInput ? nameInput.value.trim() || "Untitled" : "Untitled";
      const template = TEMPLATES[_selectedTemplateId];
      if (!template) return;

      hideNewProjectModal();
      const prog = $id("main-program");
      if (!prog) return;

      try {
        await template.create(prog, name);
      } catch (e) {
        showError("Template creation failed: " + (e.message || e));
        return;
      }
      refreshAll();
    });
  }

  /* Close on overlay click (background) */
  overlay.addEventListener("click", e => {
    if (e.target === overlay) hideNewProjectModal();
  });
});