// ── Procedure block definitions ────────────────────────────────────────────
//
// Blocks that define and call procedures:
//   WCProcedure — procedure definition (lives in Procedures tab)
//   WCProcCall  — procedure call block (lives in Algorithm tab)
//
// Each extends WCBlock (from wcblock.js).
//
// Load order dependencies:
//   wcblock.js  → WCBlock base class
//   helpers.js  → findDataSource, resolveSourceName, escapeString, toCName, commentPrefix
//   dom.js      → $id
//   draw.js     → deleteLink


/** @type {Object<string,string>} Maps library IDs to icon image paths for procedure call blocks. */
const LIB_ICONS = {
  stdio: "lib-icons/c.svg",
  stdlib: "lib-icons/c.svg",
  string: "lib-icons/c.svg",
  math: "lib-icons/c.svg",
};

// ── WCProcedure — procedure definition ─────────────────────────────────────

/** Procedure definition block with inputs/outputs/description/return-style. Lives in the Procedures tab. */
class WCProcedure extends WCBlock {
  delete() {
    if (this.dataset.readonly) { showError("Cannot delete a library procedure."); return; }
    super.delete();
  }

  connectedCallback() {
    super.connectedCallback();
    this._el.naturalName = this._require(".proc-natural-name");
    this._el.techName = this._require(".proc-tech-name");
    this._el.inputs = this._require(".proc-inputs");
    this._el.outputs = this._require(".proc-outputs");
    this._el.description = this.querySelector(".proc-description");
    this._el.descBody = this.querySelector(".proc-desc-body");

    this._require(".proc-add-input").addEventListener("click", () => {
      if (this.dataset.readonly) return;
      this._addParamRow(this._el.inputs, "in");
    });
    this._require(".proc-add-output").addEventListener("click", () => {
      if (this.dataset.readonly) return;
      this._addParamRow(this._el.outputs, "out");
    });

    this._el.naturalName.addEventListener("input", () => {
      if (!this.dataset.readonly) {
        this._el.techName.textContent = toCName(this._el.naturalName.value) || "proc";
      }
    });

    this._el.returnStyle = this.querySelector(".proc-return-style");
    if (this._el.returnStyle) {
      this.dataset.returnStyle = this._el.returnStyle.value;
      this._el.returnStyle.addEventListener("change", () => {
        if (this.dataset.readonly) return;
        this.dataset.returnStyle = this._el.returnStyle.value;
      });
    }
  }

  _addParamRow(container, dir) {
    const row = document.createElement("div");
    row.className = "proc-param-row";
    const readonly = this.dataset.readonly;
    row.innerHTML =
      `<input class="proc-param-name" placeholder="name" value=""${readonly ? " readonly" : ""}>` +
      `<input class="proc-param-type" placeholder="type" value="scalar"${readonly ? " readonly" : ""}>` +
      (readonly ? "" : `<button class="proc-param-del" title="remove">&times;</button>`);
    if (!readonly) {
      row.querySelector(".proc-param-del").addEventListener("click", () => {
        row.remove();
      });
    }
    container.appendChild(row);
  }

  getLibrary() {
    const pane = this.closest(".lib-pane");
    return pane ? pane.dataset.libName : "unknown";
  }

  getQualifiedName() {
    return this.getLibrary() + "/" + (this._el.techName.textContent || "unnamed");
  }

  getInputParams() {
    return this._getParams(this._el.inputs);
  }

  getOutputParams() {
    return this._getParams(this._el.outputs);
  }

  _getParams(container) {
    return Array.from(container.querySelectorAll(".proc-param-row")).map(row => ({
      name: row.querySelector(".proc-param-name").value || "arg",
      type: row.querySelector(".proc-param-type").value || "scalar"
    }));
  }

  saveData() {
    return {
      library: this.getLibrary(),
      naturalName: this._el.naturalName.value,
      name: this._el.techName.textContent,
      inputs: this.getInputParams(),
      outputs: this.getOutputParams(),
      returnStyle: this._el.returnStyle ? this._el.returnStyle.value : (this.dataset.returnStyle || "pointer"),
      readonly: !!this.dataset.readonly,
      formatString: this.dataset.formatString !== undefined,
      description: this._el.descBody ? this._el.descBody.textContent : "",
      descOpen: this._el.description ? this._el.description.open : false
    };
  }
  restoreData(d) {
    this._el.naturalName.value = d.naturalName || "";
    this._el.techName.textContent = d.name || "proc";
    if (d.readonly) this.dataset.readonly = "true";
    if (d.formatString) this.dataset.formatString = "true";
    if (d.returnStyle) {
      this.dataset.returnStyle = d.returnStyle;
      if (this._el.returnStyle) this._el.returnStyle.value = d.returnStyle;
    }
    if (this._el.descBody && d.description) this._el.descBody.textContent = d.description;
    if (this._el.description && d.descOpen) this._el.description.open = true;
    for (const p of (d.inputs || [])) {
      this._addParamRow(this._el.inputs, "in");
      const rows = this._el.inputs.querySelectorAll(".proc-param-row");
      const last = rows[rows.length - 1];
      last.querySelector(".proc-param-name").value = p.name || "arg";
      last.querySelector(".proc-param-type").value = p.type || "scalar";
    }
    for (const p of (d.outputs || [])) {
      this._addParamRow(this._el.outputs, "out");
      const rows = this._el.outputs.querySelectorAll(".proc-param-row");
      const last = rows[rows.length - 1];
      last.querySelector(".proc-param-name").value = p.name || "arg";
      last.querySelector(".proc-param-type").value = p.type || "scalar";
    }
  }

  generateOwnCode() { return ""; }
}


// ── WCProcCall — procedure call block ──────────────────────────────────────

/** @type {RegExp} Matches C printf-format specifiers, capturing the type character. */
const _FMT_SPEC_RE = /%(?:[+\- #0]*\d*(?:\.\d+)?)([diufFeEgGxXoscpaAn%])/g;

/**
 * Maps a printf format specifier character to a C data type.
 * @param {string} spec Single format character (e.g. "d", "f", "s")
 * @returns {string} "int", "double", or "string"
 */
function _specDataType(spec) {
  if ("di".includes(spec))   return "int";
  if ("u".includes(spec))    return "int";
  if ("fFeEgGaA".includes(spec)) return "double";
  if ("s".includes(spec))    return "string";
  return "int";
}

/** Procedure call block with dynamic argument fields, format-string support, and error-handling hooks. Lives in the Algorithm tab. */
class WCProcCall extends WCBlock {
  connectedCallback() {
    super.connectedCallback();
    this._selectedProc = "";
    this._fmtProc = null;
    this._fmtInput = null;
    this._fmtObserver = null;
    this._el.icon = this._require(".proccall-icon");
    this._el.natName = this._require(".proccall-nat-name");
    this._el.techName = this._require(".proccall-tech-name");
    this._el.changeBtn = this._require(".proccall-change-btn");
    this._el.nameInput = this._require(".proccall-name");
    this._el.nameRow = this._require(".proccall-name-row");
    this._el.inputs = this._require(".proccall-inputs");
    this._el.outputs = this._require(".proccall-outputs");
    this._el.errHook = this.querySelector(".proccall-error-hook");
    this._el.fmtargs = this._require(".proccall-fmtargs");
    this._el.fmtargsList = this._require(".proccall-fmtargs-list");
    this._el.addFmtArgBtn = this._require(".proccall-add-fmtarg");
    this._el.addFmtArgBtn.addEventListener("click", () => this._addFormatArg());

    const openBrowser = () => {
      const current = this._selectedProc;
      showProcedureBrowser(current, (qname) => {
        if (qname) this.setProcedure(qname);
      });
    };

    this._el.natName.addEventListener("click", openBrowser);
    this._el.changeBtn.addEventListener("click", openBrowser);
    this._initTimer = setTimeout(() => this._rebuildParams(), 0);
  }

  setProcedure(qname) {
    this._selectedProc = qname || "";
    const libName = qname ? qname.split("/")[0] : "";
    if (this._el.natName) {
      if (qname) {
        let natName = qname.split("/")[1] || qname;
        let techName = qname.split("/")[1] || qname;
        for (const proc of document.querySelectorAll("wc-procedure")) {
          if (proc.getQualifiedName() === qname) {
            const nat = proc.querySelector(".proc-natural-name");
            if (nat && nat.value) natName = nat.value;
            techName = (proc.querySelector(".proc-tech-name") || {}).textContent || techName;
            break;
          }
        }
        this._el.natName.textContent = natName;
        this._el.natName.title = qname;
        this._el.techName.textContent = techName;
        this._el.techName.title = qname;
        this._el.icon.src = LIB_ICONS[libName] || "";
        this._el.icon.alt = libName;
      } else {
        this._el.natName.textContent = "(select procedure)";
        this._el.natName.title = "";
        this._el.techName.textContent = "";
        this._el.techName.title = "";
        this._el.icon.src = "";
        this._el.icon.alt = "";
      }
    }
    this._rebuildParams();
  }

  _rebuildParams() {
    const qname = this._selectedProc;

    for (const container of [this._el.inputs, this._el.outputs]) {
      for (const hook of container.querySelectorAll(".hook")) {
        const paths = [...document.querySelectorAll("path.flow, path.flow-data")];
        for (const path of paths) {
          if (path.fromHook === hook || path.toHook === hook) {
            deleteLink(path);
          }
        }
      }
    }
    this._el.inputs.innerHTML = "";
    this._el.outputs.innerHTML = "";

    let returnStyle = "pointer";
    if (qname) {
      for (const proc of document.querySelectorAll("wc-procedure")) {
        if (proc.getQualifiedName() === qname) {
          returnStyle = proc.dataset.returnStyle || "pointer";
          this._cachedReturnStyle = returnStyle;
          for (const p of proc.getInputParams()) {
            this._createArgField(this._el.inputs, p, "in");
          }
          if (returnStyle !== "error") {
            for (const p of proc.getOutputParams()) {
              this._createArgField(this._el.outputs, p, "out");
            }
          }
          break;
        }
      }
    }

    this._setupFormatStringArgs();

    const isError = returnStyle === "error";
    const hasReturnValue = returnStyle === "error" || returnStyle === "value";
    if (this._el.errHook) {
      this._el.errHook.classList.toggle("visible", hasReturnValue);
    }
    if (this._el.nameRow) {
      this._el.nameRow.style.display = isError ? "none" : "";
    }
  }

  _setupFormatStringArgs() {
    const qname = this._selectedProc;
    let fmtProc = null;
    if (qname) {
      for (const proc of document.querySelectorAll("wc-procedure")) {
        if (proc.getQualifiedName() === qname && proc.dataset.formatString !== undefined) {
          fmtProc = proc;
          break;
        }
      }
    }
    this._fmtProc = fmtProc;

    if (this._fmtObserver) { this._fmtObserver.disconnect(); this._fmtObserver = null; }

    if (!fmtProc) {
      this._el.fmtargs.style.display = "none";
      this._el.addFmtArgBtn.style.display = "none";
      this._el.fmtargsList.innerHTML = "";
      return;
    }

    this._el.fmtargs.style.display = "";
    this._fmtInput = this._el.inputs.querySelector(".proccall-arg-input");

    if (this._fmtInput) {
      this._fmtInput.addEventListener("input", () => this._rebuildFormatArgs());
    }

    this._fmtObserver = new MutationObserver(() => {
      if (this._isFmtDynamic()) this._ensureFmtUnconnected();
    });
    this._fmtObserver.observe(this._el.fmtargsList, { attributes: true, attributeFilter: ["data-connected"], subtree: true });

    this._rebuildFormatArgs();
  }

  _isFmtDynamic() {
    if (!this._fmtInput) return false;
    const hook = this._fmtInput.parentElement.querySelector(".hook");
    return hook ? findDataSource(hook) !== null : false;
  }

  _rebuildFormatArgs() {
    this._el.fmtargsList.innerHTML = "";
    const dynamic = this._isFmtDynamic();
    this._el.addFmtArgBtn.style.display = dynamic ? "" : "none";

    if (dynamic) {
      this._ensureFmtUnconnected();
      return;
    }

    const fmt = this._fmtInput ? this._fmtInput.value : "";
    const specs = this._parseFormatSpecifiers(fmt);
    for (let i = 0; i < specs.length; i++) {
      this._createFormatArg(specs[i], i);
    }
  }

  _parseFormatSpecifiers(fmt) {
    const specs = [];
    let m;
    _FMT_SPEC_RE.lastIndex = 0;
    while ((m = _FMT_SPEC_RE.exec(fmt)) !== null) {
      if (m[1] === "%") continue;
      specs.push({ full: m[0], spec: m[1] });
    }
    return specs;
  }

  _createFormatArg(spec, index) {
    const row = document.createElement("div");
    row.className = "proccall-arg-row";

    const hook = document.createElement("button");
    hook.className = "hook";
    hook.dataset.direction = "in";
    hook.dataset.linkType = "data";
    hook.dataset.type = _specDataType(spec.spec);
    hook.dataset.exit = "left";
    hook.title = `expects ${_specDataType(spec.spec)}`;

    const label = document.createElement("span");
    label.className = "proccall-arg-label";
    label.textContent = `arg${index + 1}:`;

    const input = document.createElement("input");
    input.className = "proccall-arg-input";
    input.dataset.dir = "in";
    input.dataset.paramName = `fmtArg${index}`;
    input.placeholder = spec.full;

    row.appendChild(hook);
    row.appendChild(label);
    row.appendChild(input);
    this._el.fmtargsList.appendChild(row);
    this._setupHook(hook);
    this._wrapArgInput(input);
  }

  _addFormatArg() {
    const idx = this._el.fmtargsList.querySelectorAll(".proccall-arg-row").length;
    const row = document.createElement("div");
    row.className = "proccall-arg-row";

    const hook = document.createElement("button");
    hook.className = "hook";
    hook.dataset.direction = "in";
    hook.dataset.linkType = "data";
    hook.dataset.type = "scalar";
    hook.dataset.exit = "left";
    hook.title = "expects scalar";

    const label = document.createElement("span");
    label.className = "proccall-arg-label";
    label.textContent = `arg${idx + 1}:`;

    const input = document.createElement("input");
    input.className = "proccall-arg-input";
    input.dataset.dir = "in";
    input.dataset.paramName = `fmtArg${idx}`;
    input.placeholder = `arg${idx + 1}`;

    row.appendChild(hook);
    row.appendChild(label);
    row.appendChild(input);
    this._el.fmtargsList.appendChild(row);
    this._setupHook(hook);
    this._wrapArgInput(input);
    this._ensureFmtUnconnected();
  }

  _ensureFmtUnconnected() {
    if (!this._isFmtDynamic()) return;
    const hooks = this._el.fmtargsList.querySelectorAll(".hook");
    const hasFree = [...hooks].some(h => !h.dataset.connected);
    if (!hasFree) this._addFormatArg();
  }

  _wrapArgInput(input) {
    if (input.style.display === "none") return;
    const display = document.createElement("span");
    display.className = "field-display";
    const update = () => { display.textContent = input.value || input.placeholder || ""; };
    update();
    input.addEventListener("change", update);
    input.addEventListener("input", update);
    input.parentNode.insertBefore(display, input);
    input.style.display = "none";
  }

  _createArgField(container, param, dir) {
    const row = document.createElement("div");
    row.className = "proccall-arg-row";

    const label = document.createElement("span");
    label.className = "proccall-arg-label";
    label.textContent = param.name + ":";

    const input = document.createElement("input");
    input.className = "proccall-arg-input";
    input.placeholder = param.name;
    input.dataset.dir = dir;
    input.dataset.paramName = param.name;
    input.dataset.paramType = param.type;

    const hook = document.createElement("button");
    hook.className = "hook";
    hook.dataset.direction = dir === "in" ? "in" : "out";
    hook.dataset.linkType = "data";
    hook.dataset.type = param.type;
    hook.dataset.exit = dir === "in" ? "left" : "right";
    hook.title = (dir === "in" ? "expects " : "") + param.type;

    if (dir === "in") {
      row.appendChild(hook);
      row.appendChild(label);
      row.appendChild(input);
    } else {
      row.appendChild(label);
      row.appendChild(input);
      row.appendChild(hook);
    }

    container.appendChild(row);
    this._setupHook(hook);
    this._wrapArgInput(input);
  }

  _sourceName(block) {
    const name = resolveSourceName(block);
    if (!name) return "";
    return block.dataType === "string" ? name + ".data" : name;
  }

  generateOwnCode() {
    const qname = this._selectedProc;
    if (!qname) return "";
    const parts = qname.split("/");
    const procName = parts[1] || qname;

    let returnStyle = this._cachedReturnStyle || "pointer";

    const inputs = [];
    const outputs = [];
    for (const row of this._el.inputs.querySelectorAll(".proccall-arg-row")) {
      const hook = row.querySelector(".hook");
      const inp = row.querySelector(".proccall-arg-input");
      const source = hook ? findDataSource(hook) : null;
      if (source) {
        inputs.push(this._sourceName(source));
      } else {
        let val = inp.value || inp.placeholder;
        if (inp.dataset.paramType === "string") val = `"${escapeString(val)}"`;
        inputs.push(val);
      }
    }
    for (const row of this._el.outputs.querySelectorAll(".proccall-arg-row")) {
      const inp = row.querySelector(".proccall-arg-input");
      outputs.push("&" + (inp.value || inp.placeholder));
    }
    if (this._fmtProc) {
      for (const row of this._el.fmtargsList.querySelectorAll(".proccall-arg-row")) {
        const hook = row.querySelector(".hook");
        const inp = row.querySelector(".proccall-arg-input");
        const source = hook ? findDataSource(hook) : null;
        if (source) {
          inputs.push(this._sourceName(source));
        } else {
          let val = inp.value || inp.placeholder;
          if (hook.dataset.type === "string") val = `"${escapeString(val)}"`;
          inputs.push(val);
        }
      }
    }

    const hasErrPath = this._el.errHook && this._el.errHook.classList.contains("visible") &&
      Array.from(this.wcNextFlow).some(p => p.fromHook === this._el.errHook);

    // For error-capable calls, the call is emitted inside generateFlowCode
    // (as part of the if-condition) to avoid double execution.
    if (returnStyle === "error" && hasErrPath) return "";

    if (returnStyle === "value" && outputs.length === 1 && hasErrPath) {
      const outVar = outputs[0].replace(/^&/, "");
      return `  ${outVar} = ${procName}(${inputs.join(", ")});\n`;
    }

    if (returnStyle === "error") {
      return `  ${procName}(${inputs.join(", ")});\n`;
    }

    if (returnStyle === "value" && outputs.length === 1) {
      return `  ${procName}(${inputs.join(", ")});\n`;
    }
    const args = [...inputs, ...outputs].join(", ");
    return `  ${procName}(${args});\n`;
  }

  generateFlowCode() {
    const hasErrPath = this._el.errHook && this._el.errHook.classList.contains("visible") &&
      Array.from(this.wcNextFlow).some(p => p.fromHook === this._el.errHook);
    if (!hasErrPath) return WCBlock.prototype.generateFlowCode.call(this);

    const qname = this._selectedProc;
    if (!qname) return "";
    const parts = qname.split("/");
    const procName = parts[1] || qname;

    let returnStyle = this._cachedReturnStyle || "pointer";

    const inputs = [];
    const outputs = [];
    for (const row of this._el.inputs.querySelectorAll(".proccall-arg-row")) {
      const hook = row.querySelector(".hook");
      const inp = row.querySelector(".proccall-arg-input");
      const source = hook ? findDataSource(hook) : null;
      if (source) {
        inputs.push(this._sourceName(source));
      } else {
        inputs.push(inp.value || inp.placeholder);
      }
    }
    for (const row of this._el.outputs.querySelectorAll(".proccall-arg-row")) {
      const inp = row.querySelector(".proccall-arg-input");
      outputs.push("&" + (inp.value || inp.placeholder));
    }
    if (this._fmtProc) {
      for (const row of this._el.fmtargsList.querySelectorAll(".proccall-arg-row")) {
        const hook = row.querySelector(".hook");
        const inp = row.querySelector(".proccall-arg-input");
        const source = hook ? findDataSource(hook) : null;
        if (source) {
          inputs.push(this._sourceName(source));
        } else {
          inputs.push(inp.value || inp.placeholder);
        }
      }
    }

    const args = inputs.join(", ");
    const errTarget = Array.from(this.wcNextFlow)
      .filter(p => p.fromHook === this._el.errHook)
      .map(p => p.toElement)[0];
    const okTarget = Array.from(this.wcNextFlow)
      .filter(p => p.fromHook !== this._el.errHook)
      .map(p => p.toElement)[0];

    let code = "";
    if (returnStyle === "error") {
      code += `  if (${procName}(${args}) != 0) goto ${errTarget.id};\n`;
    } else if (returnStyle === "value" && outputs.length === 1) {
      const outVar = outputs[0].replace(/^&/, "");
      code += `  if (${outVar} != 0) goto ${errTarget.id};\n`;
    }
    if (okTarget) code += `  goto ${okTarget.id};\n`;
    return code;
  }

  saveData() {
    const args = {};
    for (const inp of this.querySelectorAll(".proccall-arg-input")) {
      args[inp.dataset.dir + ":" + inp.dataset.paramName] = inp.value;
    }
    return { selected: this._selectedProc, name: this._el.nameInput.value, args };
  }
  restoreData(d) {
    if (this._initTimer) { clearTimeout(this._initTimer); this._initTimer = null; }
    this.setProcedure(d.selected || "");
    this._el.nameInput.value = d.name || "";
    if (d.args) {
      for (const inp of this.querySelectorAll(".proccall-arg-input")) {
        const key = inp.dataset.dir + ":" + inp.dataset.paramName;
        if (d.args[key] !== undefined) inp.value = d.args[key];
      }
    }
    if (this._fmtProc && d.args) {
      this._rebuildFormatArgs();
      for (const inp of this.querySelectorAll(".proccall-arg-input")) {
        const key = inp.dataset.dir + ":" + inp.dataset.paramName;
        if (key.startsWith("in:fmtArg") && d.args[key] !== undefined) {
          inp.value = d.args[key];
        }
      }
    }
  }
}