const fs = require("fs");
const path = require("path");

// Prepare output directory (always storage/transcriptionSummaries under project root)
const outputDir = `${__dirname}/../../../storage/transcriptionSummaries`;
if (!fs.existsSync(outputDir)) {
    fs.mkdirSync(outputDir, { recursive: true });
}

//Speaker, Sentence, Start, End

module.exports = {
    name: "summarize-transcription2", // Unique name for our function that will later be used to get the function from the map via "mapFunctions.get("example").function()"
    type: "summarizer", // value used to differentiate each module to order them in the UI
    displayname: "Summarizer",  // The displayname used within the UI
    async function(args) {
        return new Promise(async (resolve, reject) => {
            let inputJson = args.json;

            //JSON Path
            if (args.jsonPath) {
                try {
                    const raw = fs.readFileSync(args.jsonPath, "utf-8");
                    inputJson = JSON.parse(raw);
                } catch (e) {
                    console.error("Failed to load JSON from file:", e);
                    return { error: "Could not read JSON from file path." };
                }
            }
            // JSON parsen
                if (typeof args === "string") {
                    try {
                        await new Promise((res) => {
                            fs.readFile(args, 'utf8', function (err, data) {
                                if (err) throw err;
                                inputJson = JSON.parse(data);
                                res()
                            });
                        })
                    } catch (e) {
                        console.log("Invalid JSON in summarize-transcription");
                        console.log(e)
                        return { error: "Invalid JSON" };
                    }
                }

            const words = inputJson.words;
            if (!Array.isArray(words)) {
                return { error: "No words Array found" };
            }

            const ENDINGS = [".", "!", "?"]; // '...' auch als Satzende ?
            const ABBREVIATIONS = new Set(["z.B.", "bzw.", "u.a.", "Dr.", "Mr.", "Mrs.", "Prof.", "etc."]); //TODO weitere Ergaenzen

            const result = [];
            let currentSentence = "";
            let currentSpeaker = null;
            let startTime = null;
            let endTime = null;

            for (const w of words) {
                if (!currentSpeaker) currentSpeaker = w.speaker;
                if (startTime === null) startTime = w.start;
                endTime = w.end;
        
                //speaker changing
                if (currentSpeaker !== w.speaker && currentSentence) {
                    result.push({
                        speaker: currentSpeaker,
                        sentence: currentSentence,
                        start: startTime,
                        end: endTime
                    });
                    currentSentence = "";
                    startTime = w.start;
                }
                currentSpeaker = w.speaker;
                currentSentence += (currentSentence ? " " : "") + w.text; //sentence beginning or not
                const lastWord = w.text.trim();
                const lastChar = lastWord.slice(-1);
                const isAbbreviation = ABBREVIATIONS.has(lastWord);

                //sentence ending
                if (ENDINGS.includes(lastChar) && !isAbbreviation) {
                    result.push({
                        speaker: currentSpeaker,
                        sentence: currentSentence,
                        start: startTime,
                        end: endTime
                    });
                    currentSentence = "";
                    startTime = null;
                    endTime = null;
                    currentSpeaker = null;
                }
            }

            // safe last sentence 
            if (currentSentence) {
                result.push({
                    speaker: currentSpeaker,
                    sentence: currentSentence,
                    start: startTime,
                    end: endTime
                });
            }


            // Output as Text
            const output = result.map(r => 
                `Sprecher ${r.speaker} [${r.start.toFixed(2)} - ${r.end.toFixed(2)}]: ${r.sentence}`
            );

            // Output on cosole
            //console.log("\n------------\nMerged Transcription Result:\n", output, "\n------------\n");

            try {
                const jsonPath = path.join(outputDir, "transcription_result.json");
                fs.writeFileSync(jsonPath, JSON.stringify(result, null, 2), "utf-8");

                const txtPath = path.join(outputDir, "transcription_result.txt");
                fs.writeFileSync(txtPath, output.join("\n"), "utf-8");

                console.log(`Summary successfully saved:\n- ${jsonPath}\n- ${txtPath}`);
                resolve(jsonPath);
            } catch (err) {
                console.error("Error saving Summary:", err);
                reject(err);
            }
        })
    }
}