/* play/player_manager.c — 播放线程：URL 获取(Hi-res 逐档降级)→缓存(命中直接播/否则流式落盘)→
 * minimp3 解码→audio_out 直写。UI 不卡（网络+解码全在此线程）。
 *
 * 模型：一个持久的播放线程。外层循环取「目标曲目」，run_song() 负责一首歌的
 *   「下载(缓冲) → 解码 → 输出 → 结束/被指令打断」。暂停=冻结（停读停写停推 pos，状态置 PAUSED）；
 *   seek=重开解码器+输出并 seek 到目标 ms（字节 offset 近似）；下一/上一首=打断当前 run_song 返回外层。
 * 所有跨线程共享状态在 g_play (mu)。g_st.ctx 的 device_id/cookie/cache 在播放期间稳定（登出会先停播）。
 * 返回码/错误经 g_play.err/errmsg 供 UI 提示。
 */
#include "../ncm_app_internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include "minimp3_ex.h"

static pthread_t g_thr;
static int       g_thr_on;
static int       g_want_run = 1;     /* 线程运行标志（quit=0） */
#define PCM_CHUNK 8192               /* 每块交织样本数（双声道 → 4096 帧） */

/* ---- 线程内部一次性歌的状态 ---- */
static char      g_path[512];        /* 本地 mp3 路径（缓存） */
static int64_t   g_file_bytes;
static int       g_level;            /* 音质档（来自设置） */
static int       g_cache_gb;

int player_manager_state(void) { int s; pthread_mutex_lock(&g_play.mu); s = g_play.state; pthread_mutex_unlock(&g_play.mu); return s; }
int player_manager_playing_song(void) { int s; pthread_mutex_lock(&g_play.mu); s = g_play.cur_song; pthread_mutex_unlock(&g_play.mu); return s; }
int64_t player_manager_pos_ms(void) { int64_t p; pthread_mutex_lock(&g_play.mu); p = g_play.pos_ms; pthread_mutex_unlock(&g_play.mu); return p; }
int64_t player_manager_dur_ms(void) { int64_t d; pthread_mutex_lock(&g_play.mu); d = g_play.dur_ms; pthread_mutex_unlock(&g_play.mu); return d; }
int player_manager_error(void) { int e; pthread_mutex_lock(&g_play.mu); e = g_play.err; pthread_mutex_unlock(&g_play.mu); return e; }

void player_manager_set_quality(int level, int cache_gb)
{
    g_level = level;
    g_cache_gb = cache_gb;
    pthread_mutex_lock(&g_play.mu);
    g_play.err = 0;
    ncm_cache_set_limit_gb(&g_st.ctx.cache, cache_gb);
    pthread_mutex_unlock(&g_play.mu);
}

void player_manager_play(int song_idx)
{
    pthread_mutex_lock(&g_play.mu);
    g_play.cur_song = song_idx;
    g_play.cmd = 0;
    g_play.state = NCM_PC_BUFFER;
    g_play.pos_ms = 0;
    g_play.seq++;
    pthread_mutex_unlock(&g_play.mu);
}

void player_manager_pause(int on)
{
    pthread_mutex_lock(&g_play.mu);
    if (on) { if (g_play.state == NCM_PC_PLAYING) g_play.state = NCM_PC_PAUSED; }
    else    { if (g_play.state == NCM_PC_PAUSED)  g_play.state = NCM_PC_PLAYING; }
    pthread_mutex_unlock(&g_play.mu);
}

void player_manager_seek(int64_t ms)
{
    pthread_mutex_lock(&g_play.mu);
    g_play.cmd = NCM_CTL_SEEK;
    g_play.cmd_seek_ms = ms;
    pthread_mutex_unlock(&g_play.mu);
}

void player_manager_next(int dir)
{
    pthread_mutex_lock(&g_play.mu);
    int c = g_play.cur_song + dir;
    if (c < 0) c = 0;
    if (c >= g_st.song_count) c = g_st.song_count - 1;
    if (c != g_play.cur_song) {
        g_play.cur_song = c;
        g_play.cmd = 0;
        g_play.state = NCM_PC_BUFFER;
        g_play.pos_ms = 0;
        g_play.seq++;
    }
    pthread_mutex_unlock(&g_play.mu);
}

void player_manager_stop(void)
{
    pthread_mutex_lock(&g_play.mu);
    g_play.cur_song = -1;
    g_play.state = NCM_PC_STOPPED;
    g_play.pos_ms = 0;
    g_play.seq++;
    pthread_mutex_unlock(&g_play.mu);
}

/* ---- 每首歌的播放体（在外层循环内调用）---- */
static int download_cb(void *ctx, const unsigned char *data, size_t len)
{
    return ncm_cache_write((ncm_cache_writer_t *)ctx, data, len);
}

/* 得到本地 mp3 路径 + 文件大小。命中缓存直接返回；否则 URL 降级 + 流式落缓存。
 * 返回 NCM_OK 或负错误码。 */
static int song_local_file(int idx, char *path, size_t psz, int64_t *bytes)
{
    const ncm_song_t *s = &g_st.songs[idx];
    const char *id = s->id;

    /* 缓存命中 → 离线直接播 */
    if (ncm_cache_lookup(&g_st.ctx.cache, id, ".mp3", path, psz) == NCM_OK) {
        struct stat st;
        if (stat(path, &st) == 0) { *bytes = (int64_t)st.st_size; return NCM_OK; }
    }

    /* 播放地址：从 g_level 降级，只收 mp3 */
    ncm_play_url_t u;
    int rc = ncm_api_song_url_auto(g_st.ctx.device_id, g_st.ctx.cookie, id, g_level, &u);
    if (rc != NCM_OK) return rc;
    if (!u.url[0]) return NCM_ERR_NOTFOUND;

    /* 流式下载到缓存 temp → commit（稳妥者：先落盘再播） */
    ncm_cache_writer_t *w = NULL;
    rc = ncm_cache_open(&g_st.ctx.cache, id, ".mp3", &w);
    if (rc != NCM_OK) return rc;

    ncm_http_req_t req;
    memset(&req, 0, sizeof req);
    req.url = u.url;
    req.method = "GET";
    req.extra_hdrs = "User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) "
                     "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36";
    req.verify_ca = NCM_HTTP_VERIFY_DEFAULT;
    req.timeout_ms = 30000;

    ncm_http_resp_t resp;
    size_t maxb = (u.size > 0 && u.size < (64LL << 20)) ? (size_t)u.size : (64u << 20);
    rc = ncm_http_download(&req, download_cb, w, maxb, &resp);
    if (rc != NCM_OK || resp.status != 200) {
        ncm_cache_abort(w);
        return (rc != NCM_OK) ? rc : NCM_ERR_HTTP;
    }
    rc = ncm_cache_commit(w);
    if (rc != 0) return rc;
    if (ncm_cache_lookup(&g_st.ctx.cache, id, ".mp3", path, psz) != NCM_OK)
        return NCM_ERR_NOENT;
    struct stat st;
    if (stat(path, &st) == 0) *bytes = (int64_t)st.st_size;
    return NCM_OK;
}

static void set_err(int err, const char *msg)
{
    pthread_mutex_lock(&g_play.mu);
    g_play.err = err;
    if (msg) { ncm_strlcpy(g_play.errmsg, msg, sizeof g_play.errmsg); }
    g_play.state = NCM_PC_STOPPED;
    pthread_mutex_unlock(&g_play.mu);
}

/* 一首歌：下载→解码→输出，直到结束或被打断。返回后由外层处理下一首。 */
static void run_song(int idx)
{
    int64_t file_bytes = 0;
    char path[512];
    int rc = song_local_file(idx, path, sizeof path, &file_bytes);
    if (rc != NCM_OK) {
        const char *m = (rc == NCM_ERR_NOTFOUND) ? "no stream (VIP/copyright)"
                       : (rc == NCM_ERR_AUTH) ? "session expired" : "load failed";
        set_err(rc, m);
        return;
    }
    ncm_strlcpy(g_path, path, sizeof g_path);
    g_file_bytes = file_bytes;

    const ncm_song_t *s = &g_st.songs[idx];
    int64_t dur = s->duration_ms > 0 ? s->duration_ms : 0;

    mp3dec_ex_t dec;
    memset(&dec, 0, sizeof dec);
    if (mp3dec_ex_open(&dec, path, MP3D_SEEK_TO_BYTE) != 0) { set_err(NCM_ERR_IO, "decode open failed"); return; }

    /* 音频输出：解码器输出 S16_LE（minimp3 默认）；用 44100/2ch 直开 */
    if (audio_out_open(44100, 2, 16) != 0) { mp3dec_ex_close(&dec); set_err(NCM_ERR_IO, "audio open failed"); return; }

    /* 状态→播放 */
    pthread_mutex_lock(&g_play.mu);
    g_play.state = NCM_PC_PLAYING;
    g_play.pos_ms = 0;
    g_play.dur_ms = dur;
    g_play.err = 0;
    pthread_mutex_unlock(&g_play.mu);

    mp3d_sample_t pcm[PCM_CHUNK];
    int64_t frames_done = 0;          /* 已输出帧（每通道） */
    int need_seek_ms = -1;

    for (;;) {
        if (g_app_quit) break;

        /* 取命令 */
        pthread_mutex_lock(&g_play.mu);
        int cmd = g_play.cmd; g_play.cmd = 0;
        int64_t seek_ms = g_play.cmd_seek_ms;
        int cur = g_play.cur_song;
        int st  = g_play.state;
        pthread_mutex_unlock(&g_play.mu);

        if (cur != idx) break;               /* 切歌 → 回外层 */
        if (st == NCM_PC_STOPPED) break;

        if (cmd == NCM_CTL_SEEK && seek_ms >= 0) { need_seek_ms = (int)seek_ms; }

        if (st == NCM_PC_PAUSED) { usleep(40 * 1000); continue; }   /* 冻结 */

        if (need_seek_ms >= 0) {
            /* 重开并 seek：关闭后重开（字节 offset 近似） */
            audio_out_close();
            mp3dec_ex_close(&dec);
            memset(&dec, 0, sizeof dec);
            if (mp3dec_ex_open(&dec, path, MP3D_SEEK_TO_BYTE) != 0) { set_err(NCM_ERR_IO, "seek reopen failed"); break; }
            if (audio_out_open(44100, 2, 16) != 0) { set_err(NCM_ERR_IO, "audio reopen failed"); break; }
            int64_t target = (g_file_bytes > 0 && dur > 0)
                             ? (int64_t)g_file_bytes * need_seek_ms / dur : 0;
            mp3dec_ex_seek(&dec, (uint64_t)(target > 0 ? target : 0));
            frames_done = (int64_t)need_seek_ms * 44100 / 1000;
            need_seek_ms = -1;
            continue;
        }

        size_t got = mp3dec_ex_read(&dec, pcm, PCM_CHUNK);
        if (got == 0) break;                         /* 播完 */
        int frames = (int)(got / 2);
        if (audio_out_write(pcm, frames) != frames)   break;
        frames_done += frames;
        /* 更新进度（~200ms 节流）*/
        int64_t pos = frames_done * 1000 / 44100;
        pthread_mutex_lock(&g_play.mu);
        g_play.pos_ms = pos;
        if (dur > 0 && pos >= dur) g_play.pos_ms = dur;
        pthread_mutex_unlock(&g_play.mu);
    }

    audio_out_close();
    mp3dec_ex_close(&dec);
    /* 若应继续播下一首且非因命令打断，由外层处理（外层见 cur==idx 且需自然结束） */
}

/* 外层播放线程循环 */
static void *player_thread(void *arg)
{
    (void)arg;
    while (g_want_run && !g_app_quit) {
        pthread_mutex_lock(&g_play.mu);
        int cur = g_play.cur_song;
        int st  = g_play.state;
        pthread_mutex_unlock(&g_play.mu);

        if (cur < 0 || cur >= g_st.song_count || st == NCM_PC_STOPPED) {
            usleep(60 * 1000);
            continue;
        }
        /* 以本地快照播放（idx 被外层线程独占，无需再锁） */
        run_song(cur);

        pthread_mutex_lock(&g_play.mu);
        int cur2 = g_play.cur_song;
        int st2  = g_play.state;
        pthread_mutex_unlock(&g_play.mu);
        /* 自然播完且无新命令 → 顺延下一首；否则回到循环等待 */
        if (cur2 >= 0 && cur2 < g_st.song_count && st2 != NCM_PC_STOPPED && cur2 == cur) {
            int nx = cur + 1;
            if (nx < g_st.song_count) { player_manager_next(1); }
            else { player_manager_stop(); }
        } else {
            usleep(50 * 1000);
        }
    }
    return NULL;
}

/* ---- 歌词后台加载（二期）：UI 不阻塞 —— 持久 worker 监视当前播放歌曲，首播/切歌/自动顺延
 *      时在独立线程拉取并解析，UI 经 lyric_state() 判「加载中 / 无词」。 ----
 *      现存 race（§10.9 FM4，UI 读 lyrics 与 worker 写）为良性：数组定长、越界已防护，
 *      最坏显示一帧旧/空行，下一 tick 自愈；与 g_st.songs 写读竞态同接受。 */
static pthread_mutex_t g_lyrmu = PTHREAD_MUTEX_INITIALIZER;
static pthread_t       g_lyr_thr;
static int             g_lyr_thr_on;
static volatile int    g_lyr_state;       /* 0=空闲/未拉 1=加载中 2=已拉完 */
static char            g_lyr_song_id[32]; /* 歌词归属歌曲 id */

static void *lyric_worker(void *arg)
{
    (void)arg;
    char last_id[32] = "";
    while (!g_app_quit) {
        usleep(300 * 1000);
        int idx;
        pthread_mutex_lock(&g_play.mu); idx = g_play.cur_song; pthread_mutex_unlock(&g_play.mu);
        if (idx < 0 || idx >= g_st.song_count) {
            lyric_clear();
            pthread_mutex_lock(&g_lyrmu);
            g_lyr_song_id[0] = 0;
            g_lyr_state = 0;
            pthread_mutex_unlock(&g_lyrmu);
            last_id[0] = 0;
            continue;
        }
        const char *id = g_st.songs[idx].id;
        if (!id[0]) continue;
        if (strcmp(id, last_id) == 0) continue;      /* 同一曲已拉/在拉 */

        ncm_strlcpy(last_id, id, sizeof last_id);
        lyric_clear();
        pthread_mutex_lock(&g_lyrmu);
        g_lyr_state = 1;                              /* 加载中 */
        pthread_mutex_unlock(&g_lyrmu);

        char *lrc = (char *)malloc(64 * 1024);
        char *tl  = (char *)malloc(32 * 1024);
        if (!lrc || !tl) {
            free(lrc); free(tl);
            pthread_mutex_lock(&g_lyrmu); g_lyr_state = 0; pthread_mutex_unlock(&g_lyrmu);
            continue;
        }
        int rc = ncm_api_lyric(g_st.ctx.device_id, g_st.ctx.cookie, id, lrc, 64 * 1024, tl, 32 * 1024);
        if (rc == NCM_OK) lyric_parse(lrc, tl);
        free(lrc); free(tl);

        pthread_mutex_lock(&g_lyrmu);
        ncm_strlcpy(g_lyr_song_id, id, sizeof g_lyr_song_id);
        g_lyr_state = 2;                              /* 拉完（可能 0 行=无词） */
        pthread_mutex_unlock(&g_lyrmu);
    }
    return NULL;
}

static void lyric_ensure_worker(void)
{
    pthread_mutex_lock(&g_lyrmu);
    if (!g_lyr_thr_on) {
        g_lyr_thr_on = 1;
        if (pthread_create(&g_lyr_thr, NULL, lyric_worker, NULL) == 0) pthread_detach(g_lyr_thr);
        else g_lyr_thr_on = 0;
    }
    pthread_mutex_unlock(&g_lyrmu);
}

/* 为当前曲目「异步」拉歌词：确保后台 worker 在跑即返回（UI 不阻塞网络/解析）。
 * 实际拉取+解析在 worker 线程（约 0.3s 内开始），结束置 lyric_state()=2。 */
int player_manager_load_lyric(void)
{
    lyric_ensure_worker();
    return NCM_OK;
}

/* 歌词加载状态（UI 判「loading / no lyric」）。 */
int lyric_state(void)
{
    int s;
    pthread_mutex_lock(&g_lyrmu);
    s = g_lyr_state;
    pthread_mutex_unlock(&g_lyrmu);
    return s;
}

int player_manager_start(void)
{
    if (g_thr_on) return 0;
    g_want_run = 1;
    g_level = g_st.level;
    g_cache_gb = g_st.cache_limit_gb;
    pthread_mutex_init(&g_play.mu, NULL);
    if (pthread_create(&g_thr, NULL, player_thread, NULL) != 0) return -1;
    g_thr_on = 1;
    return 0;
}

void player_manager_stop_thread(void)
{
    g_want_run = 0;
    g_app_quit = 1;
    audio_out_close();   /* 打断阻塞写 */
    if (g_thr_on) {
        pthread_join(g_thr, NULL);
        g_thr_on = 0;
    }
}