package main

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"time"
)

// I3BarBlock represents a single block in the i3bar protocol.
type I3BarBlock struct {
	FullText  string `json:"full_text"`
	ShortText string `json:"short_text,omitempty"`
	Color     string `json:"color"`
	Name      string `json:"name"`
	Markup    string `json:"markup,omitempty"`
}

// formatI3BarBlocks builds one i3bar block per session, each with its own color.
// For Needs Input sessions: shows wait type icon and duration.
func formatI3BarBlocks(sessions []SessionInfo, now time.Time) []I3BarBlock {
	if len(sessions) == 0 {
		return []I3BarBlock{{FullText: "vmux: no sessions", Color: "#888888", Name: "vmux"}}
	}

	blocks := make([]I3BarBlock, 0, len(sessions))
	for _, s := range sessions {
		name := shortName(s)
		if s.Workspace != "" {
			name = s.Workspace + "-" + name
		}

		var marker, color string
		switch s.State {
		case "Needs Input":
			marker = waitTypeMarker(s.WaitType)
			if s.WaitingSince != nil {
				marker += " " + shortDuration(now.Sub(*s.WaitingSince))
			}
			marker = "[" + marker + "]"
			color = "#ff0000"
		case "Working":
			marker = "[W]"
			color = "#00ff00"
		case "Idle":
			marker = "[I]"
			color = "#888888"
		default:
			marker = "[?]"
			color = "#888888"
		}

		blocks = append(blocks, I3BarBlock{
			FullText: name + marker,
			Color:    color,
			Name:     "vmux-" + s.SessionID,
		})
	}

	return blocks
}

// waitTypeMarker returns a short icon for the wait type.
func waitTypeMarker(waitType string) string {
	switch waitType {
	case "permission":
		return "⚡"
	case "question":
		return "?"
	default:
		return "!"
	}
}

// shortDuration formats a duration as compact string for i3bar.
func shortDuration(d time.Duration) string {
	if d < time.Minute {
		return fmt.Sprintf("%ds", int(d.Seconds()))
	}
	m := int(d.Minutes())
	if m < 60 {
		return fmt.Sprintf("%dm", m)
	}
	return fmt.Sprintf("%dh%dm", m/60, m%60)
}

// queryVmuxBlocks fetches sessions from daemon and returns i3bar blocks.
func queryVmuxBlocks(sockPath string) []I3BarBlock {
	client := NewClient(sockPath)
	resp, err := client.Send(Request{Action: "list"})
	if err != nil {
		return []I3BarBlock{{FullText: "vmux: offline", Color: "#888888", Name: "vmux"}}
	}
	if !resp.OK {
		return []I3BarBlock{{FullText: "vmux: error", Color: "#888888", Name: "vmux"}}
	}
	return formatI3BarBlocks(resp.Sessions, time.Now())
}

// runI3Bar runs the i3bar protocol loop on stdout, polling the daemon every 2s.
func runI3Bar(sockPath string) {
	os.Stdout.Write([]byte("{\"version\":1}\n"))
	os.Stdout.Write([]byte("[\n"))
	os.Stdout.Sync()

	first := true
	for {
		blocks := queryVmuxBlocks(sockPath)
		data, err := json.Marshal(blocks)
		if err != nil {
			log.Printf("i3bar marshal error: %v", err)
			time.Sleep(2 * time.Second)
			continue
		}

		var line string
		if first {
			line = string(data) + "\n"
		} else {
			line = "," + string(data) + "\n"
		}
		os.Stdout.Write([]byte(line))
		os.Stdout.Sync()

		first = false
		time.Sleep(2 * time.Second)
	}
}