var logSource = null;
var currentUnit = null;
var logPid = 0;
var MAX_LOG_LINES = 800;
var MIN_LOG_LINES = 500;
var logLines = [];

function escapeHtml(s) {
    return s
        .replace(/&/g, "&")
        .replace(/</g, "&lt;")
        .replace(/>/g, "&gt;")
        .replace(/"/g, "&quot;")
        .replace(/'/g, "&#39;");
}

function colorLog(line) {
    var s = escapeHtml(line);
    var levels = [
        ["TRACE", "log-trace"],
        ["DEBUG", "log-debug"],
        ["INFO", "log-info"],
        ["WARN", "log-warn"],
        ["WARNING", "log-warn"],
        ["ERROR", "log-error"],
        ["FATAL", "log-fatal"],
        ["PANIC", "log-panic"],
    ];
    for (var i = 0; i < levels.length; i++) {
        var lvl = levels[i][0],
            cls = levels[i][1];
        if (s.includes(lvl) || s.includes(lvl.toLowerCase())) {
            return '<span class="' + cls + '">' + s + "</span>";
        }
    }
    return '<span class="log-default">' + s + "</span>";
}

function connectLog(unit, target) {
    var el = typeof target === "string" ? document.getElementById(target) : target;
    if (!el) {
        console.error("[log-stream] target element not found");
        return;
    }
    if (currentUnit === unit && logSource && logSource.readyState !== EventSource.CLOSED) {
        return;
    }
    disconnectLog();
    currentUnit = unit;
    logLines = [];
    el.textContent = "";
    var source = new EventSource("/api/service/log?unit=" + encodeURIComponent(unit));
    logSource = source;
    source.onmessage = function (e) {
        if (source !== logSource) {
            return;
        }
        logLines.push(e.data);
        if (logLines.length > MAX_LOG_LINES) {
            logLines.shift();
        }
        var line = document.createElement("div");
        line.innerHTML = colorLog(e.data);
        var atBottom = el.scrollHeight - el.scrollTop - el.clientHeight < 20;
        el.appendChild(line);
        if (el.childElementCount > MAX_LOG_LINES) {
            while (el.childElementCount > MIN_LOG_LINES) {
                el.firstElementChild.remove();
            }
        }
        if (atBottom) {
            requestAnimationFrame(function () {
                el.scrollTop = el.scrollHeight;
            });
        }
    };
    source.addEventListener("pid", function (e) {
        if (source !== logSource) {
            return;
        }
        logPid = Number(e.data);
    });
    source.onerror = function () {
        if (source !== logSource) {
            return;
        }
        console.warn("[log-stream] error unit=" + unit + ", state=" + source.readyState);
    };
}

function disconnectLog() {
    if (logSource) {
        logSource.close();
        logSource = null;
    }
    if (logPid > 0) {
        fetch("/api/service/log/close?pid=" + logPid).catch(function () {});
        logPid = 0;
    }
    currentUnit = null;
    logLines = [];
}

function getCurrentUnit() {
    return currentUnit;
}

function clearLog(target) {
    logLines = [];
    var el = typeof target === "string" ? document.getElementById(target) : target;
    if (el) {
        // replaceChildren 兼容兜底 (Chrome < 86 / Safari < 14)
        if (el.replaceChildren) {
            el.replaceChildren();
        } else {
            while (el.firstChild) {
                el.removeChild(el.firstChild);
            }
        }
        el.scrollTop = 0;
    }
}

function copyLog(target) {
    var el = typeof target === "string" ? document.getElementById(target) : target;
    // 每行日志是一个独立的 div，textContent 直接拼接不会带换行，需逐行 join("\n")
    var text = el
        ? Array.prototype.map
              .call(el.children, function (c) {
                  return c.textContent;
              })
              .join("\n")
        : logLines.join("\n");
    function fallbackCopy() {
        var ta = document.createElement("textarea");
        ta.value = text;
        ta.style.position = "fixed";
        ta.style.opacity = "0";
        document.body.appendChild(ta);
        ta.select();
        var ok = document.execCommand("copy");
        ta.remove();
        alert(ok ? "复制成功" : "复制失败");
    }
    if (navigator.clipboard && navigator.clipboard.writeText) {
        navigator.clipboard
            .writeText(text)
            .then(function () {
                return alert("复制成功");
            })
            .catch(fallbackCopy);
    } else {
        fallbackCopy();
    }
}
["beforeunload", "pagehide"].forEach(function (e) {
    return window.addEventListener(e, disconnectLog);
});