package api

import (
	"io"
	"log"
	"net/http"
	"os"
	"path/filepath"
	"slices"
	"sort"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"
)

var upgrader = websocket.Upgrader{
	CheckOrigin: func(r *http.Request) bool { return true },
}

func (h *Handler) StreamLogs(c *gin.Context) {
	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
	if err != nil {
		log.Printf("websocket upgrade error: %v", err)
		return
	}
	defer conn.Close()

	clientID := conn.RemoteAddr().String()
	ch := h.streamer.Subscribe("server", clientID)
	defer h.streamer.Unsubscribe("server", clientID)

	for line := range ch {
		if err := conn.WriteMessage(websocket.TextMessage, []byte(line)); err != nil {
			break
		}
	}
}

func (h *Handler) ListLogs(c *gin.Context) {
	profilesDir := h.process.ProfilesDir()
	files := h.collectLogFiles(profilesDir, "")

	logsDir := filepath.Join(profilesDir, "logs")
	if fi, err := os.Stat(logsDir); err == nil && fi.IsDir() {
		files = append(files, h.collectLogFiles(logsDir, "logs")...)
	}

	slices.Sort(files)
	if files == nil {
		files = []string{}
	}
	c.JSON(http.StatusOK, files)
}

func (h *Handler) collectLogFiles(dir, prefix string) []string {
	entries, err := os.ReadDir(dir)
	if err != nil {
		return nil
	}
	var files []string
	for _, e := range entries {
		if !e.IsDir() {
			ext := filepath.Ext(e.Name())
			if ext == ".log" || ext == ".rpt" || e.Name() == "script.log" {
				if prefix != "" {
					files = append(files, prefix+"/"+e.Name())
				} else {
					files = append(files, e.Name())
				}
			}
		}
	}
	return files
}

func (h *Handler) StreamSteamCMDLogs(c *gin.Context) {
	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
	if err != nil {
		log.Printf("websocket upgrade error: %v", err)
		return
	}
	defer conn.Close()

	clientID := conn.RemoteAddr().String()
	ch := h.streamer.Subscribe("steamcmd", clientID)
	defer h.streamer.Unsubscribe("steamcmd", clientID)

	for line := range ch {
		if err := conn.WriteMessage(websocket.TextMessage, []byte(line)); err != nil {
			break
		}
	}
}

func (h *Handler) StreamRPTLogs(c *gin.Context) {
	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
	if err != nil {
		log.Printf("websocket upgrade error: %v", err)
		return
	}
	defer conn.Close()

	profilesDir := h.process.ProfilesDir()
	var currentPath string
	var currentOffset int64
	ticker := time.NewTicker(250 * time.Millisecond)
	defer ticker.Stop()

	for range ticker.C {
		path := findLatestRPT(profilesDir)

		if path != currentPath {
			currentPath = path
			currentOffset = 0
			if currentPath == "" {
				continue
			}
			conn.WriteMessage(websocket.TextMessage, []byte("--- tailing: "+filepath.Base(currentPath)+" ---"))
		}
		if currentPath == "" {
			continue
		}

		fi, err := os.Stat(currentPath)
		if err != nil {
			currentPath = ""
			continue
		}
		if fi.Size() <= currentOffset {
			continue
		}

		f, err := os.Open(currentPath)
		if err != nil {
			currentPath = ""
			continue
		}
		f.Seek(currentOffset, io.SeekStart)
		buf := make([]byte, fi.Size()-currentOffset)
		n, _ := io.ReadFull(f, buf)
		f.Close()

		currentOffset += int64(n)
		for _, line := range strings.Split(string(buf[:n]), "\n") {
			if line == "" {
				continue
			}
			if err := conn.WriteMessage(websocket.TextMessage, []byte(line)); err != nil {
				return
			}
		}
	}
}

func findLatestRPT(dir string) string {
	pattern := filepath.Join(dir, "arma3server_x64_*.rpt")
	matches, err := filepath.Glob(pattern)
	if err != nil || len(matches) == 0 {
		return ""
	}
	sort.Slice(matches, func(i, j int) bool {
		fi, _ := os.Stat(matches[i])
		fj, _ := os.Stat(matches[j])
		return fi.ModTime().After(fj.ModTime())
	})
	return matches[0]
}

func (h *Handler) GetLog(c *gin.Context) {
	filename := filepath.Base(c.Param("file"))
	if filename == "" || strings.ContainsRune(c.Param("file"), os.PathSeparator) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid filename"})
		return
	}
	profilesDir := h.process.ProfilesDir()
	path := filepath.Join(profilesDir, filename)

	if _, err := os.Stat(path); os.IsNotExist(err) {
		logsPath := filepath.Join(profilesDir, "logs", filename)
		if _, err2 := os.Stat(logsPath); err2 == nil {
			path = logsPath
		} else {
			c.JSON(http.StatusNotFound, gin.H{"error": "file not found"})
			return
		}
	}

	data, err := os.ReadFile(path)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.String(http.StatusOK, string(data))
}