package shine.agent.botcoder.codex;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Duration;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.TimeUnit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class CodexClient {

    private static final Logger log = LoggerFactory.getLogger(CodexClient.class);

    private final Path codexBin;
    private final Path codexWorkDir;
    private final int timeoutSeconds;
    private final AtomicReference<Process> activeProcess = new AtomicReference<>();

    public CodexClient(Path codexBin, Path codexWorkDir, int timeoutSeconds) {
        this.codexBin = codexBin;
        this.codexWorkDir = codexWorkDir;
        this.timeoutSeconds = timeoutSeconds;
    }

    public String executePrompt(String prompt, CodexStatusListener statusListener) throws IOException, InterruptedException {
        Path lastMessageFile = Files.createTempFile("shine-codex-last-message-", ".txt");
        List<String> command = new ArrayList<>();
        command.add(codexBin.toString());
        command.add("exec");
        command.add("--dangerously-bypass-approvals-and-sandbox");
        command.add("--json");
        command.add("-C");
        command.add(codexWorkDir.toString());
        command.add("-o");
        command.add(lastMessageFile.toString());
        command.add(prompt);
        log.info("Запуск codex exec, bin={}, workdir={}", codexBin, codexWorkDir);

        ProcessBuilder builder = new ProcessBuilder(command);
        builder.redirectErrorStream(true);
        Process process = builder.start();
        activeProcess.set(process);
        if (statusListener != null) {
            statusListener.onStatus("Codex запущен");
        }

        StringBuilder output = new StringBuilder();
        Thread outputThread = new Thread(() -> readOutput(process, output, statusListener));
        outputThread.setDaemon(true);
        outputThread.start();

        boolean finished;
        try {
            finished = process.waitFor(timeoutSeconds, TimeUnit.SECONDS);
        } catch (InterruptedException interrupted) {
            process.destroyForcibly();
            joinOutputThread(outputThread);
            activeProcess.compareAndSet(process, null);
            Thread.currentThread().interrupt();
            throw interrupted;
        }

        try {
            if (!finished) {
                process.destroyForcibly();
                joinOutputThread(outputThread);
                log.error("Codex timeout after {}s", timeoutSeconds);
                throw new IOException("Codex timeout after " + timeoutSeconds + "s");
            }

            joinOutputThread(outputThread);
            int exitCode = process.exitValue();
            String lastMessage = "";
            if (Files.exists(lastMessageFile)) {
                lastMessage = Files.readString(lastMessageFile, StandardCharsets.UTF_8).trim();
            }

            if (exitCode != 0) {
                log.error("Codex exit code={}, outputTail={}", exitCode, tail(output.toString(), 500));
                throw new IOException("Codex exited with code " + exitCode + ". Output: " + tail(output.toString(), 1800));
            }

            if (!lastMessage.isBlank()) {
                return lastMessage;
            }

            String fallback = extractFallbackMessage(output.toString());
            if (fallback.isBlank()) {
                throw new IOException("Codex returned empty response");
            }
            return fallback;
        } finally {
            activeProcess.compareAndSet(process, null);
            try {
                Files.deleteIfExists(lastMessageFile);
            } catch (IOException ignored) {
            }
        }
    }

    public boolean stopActiveProcess() {
        Process process = activeProcess.getAndSet(null);
        if (process == null) {
            return false;
        }
        process.destroy();
        try {
            if (!process.waitFor(2, TimeUnit.SECONDS)) {
                process.destroyForcibly();
            }
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            process.destroyForcibly();
        }
        return true;
    }

    private void readOutput(Process process, StringBuilder output, CodexStatusListener statusListener) {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream(), StandardCharsets.UTF_8))) {
            String line;
            while ((line = reader.readLine()) != null) {
                output.append(line).append('\n');
                String status = normalizeStatusLine(line);
                if (status != null && statusListener != null) {
                    statusListener.onStatus(status);
                }
            }
        } catch (Exception ignored) {
        }
    }

    private String normalizeStatusLine(String line) {
        String trimmed = line == null ? "" : line.trim();
        if (trimmed.isEmpty()) {
            return null;
        }
        if (trimmed.contains("\"type\":\"thread.started\"")) {
            return "Codex: инициализировал сессию";
        }
        if (trimmed.contains("\"type\":\"turn.started\"")) {
            return "Codex: начал обработку запроса";
        }
        if (trimmed.contains("\"type\":\"item.completed\"") && trimmed.contains("\"type\":\"agent_message\"")) {
            return "Codex: формирует финальный ответ";
        }
        if (trimmed.contains("\"type\":\"turn.completed\"")) {
            return "Codex: завершил шаг";
        }
        if (trimmed.contains("\"type\":\"error\"")) {
            return "Codex: ошибка выполнения";
        }
        if (trimmed.contains("\"type\":\"reasoning\"")) {
            return "Codex: анализирует задачу";
        }
        if (trimmed.contains("\"type\":\"function_call\"")) {
            return "Codex: вызывает инструмент";
        }
        if (trimmed.contains("\"type\":\"function_call_output\"")) {
            return "Codex: получил результат инструмента";
        }
        if (trimmed.contains("\"type\":\"message\"") && trimmed.contains("\"role\":\"assistant\"")) {
            return "Codex: формирует ответ";
        }
        if (trimmed.startsWith("mcp")) {
            return "Codex: инициализирует MCP";
        }
        if (trimmed.startsWith("tokens used")) {
            return "Codex: завершает обработку";
        }
        if (trimmed.startsWith("ERROR:")) {
            return "Codex: ошибка выполнения";
        }
        return null;
    }

    private void joinOutputThread(Thread outputThread) throws InterruptedException {
        try {
            outputThread.join(Duration.ofSeconds(2).toMillis());
        } catch (InterruptedException interrupted) {
            Thread.currentThread().interrupt();
            throw interrupted;
        }
    }

    private String extractFallbackMessage(String rawOutput) {
        String[] lines = rawOutput.split("\\R");
        for (int i = lines.length - 1; i >= 0; i--) {
            String line = lines[i].trim();
            if (line.isEmpty()) {
                continue;
            }
            if (line.startsWith("tokens used")) {
                continue;
            }
            if (line.startsWith("OpenAI Codex")) {
                continue;
            }
            if (line.startsWith("workdir:") || line.startsWith("model:") || line.startsWith("provider:")) {
                continue;
            }
            if (line.startsWith("approval:") || line.startsWith("sandbox:") || line.startsWith("reasoning")) {
                continue;
            }
            if (line.equals("user") || line.equals("exec") || line.equals("--------")) {
                continue;
            }
            return line;
        }
        return "";
    }

    private String tail(String value, int maxLen) {
        if (value.length() <= maxLen) {
            return value;
        }
        return value.substring(value.length() - maxLen);
    }
}