jhonny-editor/code/src/tools/tracks.ts

import { buildToolScript, escapeForExtendScript } from "../bridge/script-builder.js";
import { sendCommand, BridgeOptions } from "../bridge/file-bridge.js";

function isPositiveInteger(value: unknown): value is number {
  return typeof value === "number" && Number.isSafeInteger(value) && value > 0;
}

export function getTrackTools(bridgeOptions: BridgeOptions) {
  return {
    add_track: {
      description:
        "Add verified video or audio tracks to the active sequence. Returns an error if Premiere cannot add the exact requested count.",
      parameters: {
        type: "object" as const,
        properties: {
          track_type: {
            type: "string",
            enum: ["video", "audio"],
            description: "Type of track to add",
          },
          count: {
            type: "number",
            description: "Number of tracks to add (default: 1)",
          },
        },
        required: ["track_type"],
      },
      handler: async (args: { track_type: string; count?: number }) => {
        const count = args.count ?? 1;
        if (args.track_type !== "video" && args.track_type !== "audio") {
          return { success: false, error: "track_type must be either video or audio" };
        }
        if (!isPositiveInteger(count)) {
          return { success: false, error: "count must be a positive integer" };
        }

        const isVideo = args.track_type === "video";
        const script = buildToolScript(`
          var seq = app.project.activeSequence;
          if (!seq) return __error("No active sequence");

          var before = ${isVideo ? "seq.videoTracks.numTracks" : "seq.audioTracks.numTracks"};
          var expected = before + ${count};
          var method = "public DOM";
          var publicFailure = "";

          // Premiere 26.x can expose this public Sequence API but reject the
          // call. Do not report the request as successful until the DOM count
          // proves it happened. If the public call made no change, QE is a
          // bounded fallback; a partially applied public call is never retried.
          try {
            if (typeof seq.${isVideo ? "insertVideoTrackAt" : "insertAudioTrackAt"} !== "function") {
              publicFailure = "Sequence.${isVideo ? "insertVideoTrackAt" : "insertAudioTrackAt"} is unavailable";
            } else {
              ${isVideo
                ? `seq.insertVideoTrackAt(before, ${count});`
                : `seq.insertAudioTrackAt(before, ${count});`}
            }
          } catch (publicError) {
            publicFailure = publicError.toString();
          }

          var afterPublic = ${isVideo ? "seq.videoTracks.numTracks" : "seq.audioTracks.numTracks"};
          if (afterPublic !== expected && afterPublic !== before) {
            return __error("Track add partially applied through the public DOM: requested ${count} ${args.track_type} track(s), had " + before + ", now has " + afterPublic + ". It was not retried.");
          }

          if (afterPublic !== expected) {
            method = "QE fallback";
            if (typeof app.enableQE !== "function") {
              return __error("Could not add ${args.track_type} track(s): " + publicFailure + ". QE fallback is unavailable on this Premiere build.");
            }
            app.enableQE();
            if (typeof qe === "undefined" || !qe.project || typeof qe.project.getActiveSequence !== "function") {
              return __error("Could not add ${args.track_type} track(s): " + publicFailure + ". QE active-sequence access is unavailable on this Premiere build.");
            }
            var qeSeq = qe.project.getActiveSequence();
            if (!qeSeq || typeof qeSeq.addTracks !== "function") {
              return __error("Could not add ${args.track_type} track(s): " + publicFailure + ". QE addTracks is unavailable on this Premiere build.");
            }
            try {
              qeSeq.addTracks(${isVideo ? count : 0}, ${isVideo ? 0 : count}, 0, 0);
            } catch (qeError) {
              return __error("Could not add ${args.track_type} track(s): public DOM failed (" + publicFailure + ") and QE addTracks failed (" + qeError.toString() + ").");
            }
          }

          var after = ${isVideo ? "seq.videoTracks.numTracks" : "seq.audioTracks.numTracks"};
          if (after !== expected) {
            return __error("Premiere did not add the requested ${args.track_type} tracks: requested ${count}, had " + before + ", now has " + after + " (" + method + ").");
          }

          return __result({
            added: ${count},
            trackType: "${args.track_type}",
            totalTracks: after,
            method: method,
            verified: true
          });
        `);
        return sendCommand(script, bridgeOptions);
      },
    },

    delete_track: {
      description: "Delete a video or audio track from the active sequence",
      parameters: {
        type: "object" as const,
        properties: {
          track_type: {
            type: "string",
            enum: ["video", "audio"],
            description: "Type of track to delete",
          },
          track_index: {
            type: "number",
            description: "Index of the track to delete (0-based)",
          },
        },
        required: ["track_type", "track_index"],
      },
      handler: async (args: { track_type: string; track_index: number }) => {
        const script = buildToolScript(`
          var seq = app.project.activeSequence;
          if (!seq) return __error("No active sequence");
          
          ${args.track_type === "video"
            ? `if (${args.track_index} >= seq.videoTracks.numTracks) return __error("Track index out of range");
               seq.deleteVideoTrackAt(${args.track_index});`
            : `if (${args.track_index} >= seq.audioTracks.numTracks) return __error("Track index out of range");
               seq.deleteAudioTrackAt(${args.track_index});`
          }
          
          return __result({ deleted: true, trackType: "${args.track_type}", trackIndex: ${args.track_index} });
        `);
        return sendCommand(script, bridgeOptions);
      },
    },

    lock_track: {
      description: "Lock or unlock a video track",
      parameters: {
        type: "object" as const,
        properties: {
          track_index: {
            type: "number",
            description: "Video track index (0-based)",
          },
          locked: {
            type: "boolean",
            description: "True to lock, false to unlock",
          },
        },
        required: ["track_index", "locked"],
      },
      handler: async (args: { track_index: number; locked: boolean }) => {
        const script = buildToolScript(`
          var seq = app.project.activeSequence;
          if (!seq) return __error("No active sequence");
          
          if (${args.track_index} >= seq.videoTracks.numTracks) return __error("Track index out of range");
          
          var track = seq.videoTracks[${args.track_index}];
          track.setLocked(${args.locked ? 1 : 0});
          
          return __result({ trackIndex: ${args.track_index}, locked: ${args.locked}, trackName: track.name });
        `);
        return sendCommand(script, bridgeOptions);
      },
    },

    toggle_track_visibility: {
      description: "Toggle a video track's visibility (eye icon)",
      parameters: {
        type: "object" as const,
        properties: {
          track_index: {
            type: "number",
            description: "Video track index (0-based)",
          },
          visible: {
            type: "boolean",
            description: "True to show, false to hide",
          },
        },
        required: ["track_index", "visible"],
      },
      handler: async (args: { track_index: number; visible: boolean }) => {
        const script = buildToolScript(`
          var seq = app.project.activeSequence;
          if (!seq) return __error("No active sequence");
          
          if (${args.track_index} >= seq.videoTracks.numTracks) return __error("Track index out of range");
          
          var track = seq.videoTracks[${args.track_index}];
          track.setMute(${args.visible ? 0 : 1});
          
          return __result({ trackIndex: ${args.track_index}, visible: ${args.visible}, trackName: track.name });
        `);
        return sendCommand(script, bridgeOptions);
      },
    },
  };
}