package main

import (
	"fmt"
	"io"
	"strings"
	"time"
)

const (
	colorReset  = "\033[0m"
	colorGreen  = "\033[32m"
	colorYellow = "\033[33m"
	colorRed    = "\033[31m"
	colorGray   = "\033[90m"
	colorBold   = "\033[1m"
)

// DisplaySessions writes a formatted list of sessions to w.
func DisplaySessions(w io.Writer, sessions []Session, noColor bool) {
	if len(sessions) == 0 {
		fmt.Fprintln(w, "No active Claude Code sessions found.")
		return
	}

	for i, s := range sessions {
		if i > 0 {
			fmt.Fprintln(w)
		}

		stateLabel := stateColor(s.State, noColor) + s.State.String() + resetIfColor(noColor)

		branch := ""
		if s.GitBranch != "" {
			branch = " (" + s.GitBranch + ")"
		}

		worktreeInfo := ""
		if s.Worktree != "" && s.Worktree != s.CwdPath {
			worktreeInfo = " [worktree: " + s.Worktree + "]"
		}

		fmt.Fprintf(w, "[%s] %s%s%s\n", stateLabel, s.CwdPath, branch, worktreeInfo)

		if s.Preview != "" {
			lines := strings.Split(s.Preview, "\n")
			for _, line := range lines {
				fmt.Fprintf(w, "         %s\n", line)
			}
		}
	}
}

// DisplaySessionInfos writes a formatted list of SessionInfo (from daemon) to w.
// Includes workspace, label, and waiting duration.
func DisplaySessionInfos(w io.Writer, sessions []SessionInfo, noColor bool, now time.Time) {
	if len(sessions) == 0 {
		fmt.Fprintln(w, "No active Claude Code sessions found.")
		return
	}

	for i, s := range sessions {
		if i > 0 {
			fmt.Fprintln(w)
		}

		stateDisplay := s.State
		if s.State == "Needs Input" && s.WaitType != "" {
			stateDisplay = s.State + ": " + s.WaitType
		}
		stateStr := stateColorStr(s.State, noColor) + stateDisplay + resetIfColor(noColor)

		branch := ""
		if s.GitBranch != "" {
			branch = " (" + s.GitBranch + ")"
		}

		workspace := ""
		if s.Workspace != "" {
			workspace = " [ws:" + s.Workspace + "]"
		}

		label := ""
		if s.Label != "" {
			label = fmt.Sprintf(" %q", s.Label)
		}

		waiting := ""
		if s.WaitingSince != nil {
			waiting = " (depuis " + formatDuration(now.Sub(*s.WaitingSince)) + ")"
		}

		fmt.Fprintf(w, "[%s] %s%s%s%s%s\n", stateStr, s.Cwd, branch, workspace, label, waiting)

		lines := strings.Split(s.Preview, "\n")
		for i := 0; i < previewLines; i++ {
			if i < len(lines) && lines[i] != "" {
				fmt.Fprintf(w, "         %s\n", lines[i])
			} else {
				fmt.Fprintln(w)
			}
		}
	}
}

// formatDuration returns a human-readable relative duration.
func formatDuration(d time.Duration) string {
	if d < time.Minute {
		return "< 1 min"
	}

	hours := int(d.Hours())
	minutes := int(d.Minutes()) % 60

	if hours > 0 {
		if minutes > 0 {
			return fmt.Sprintf("%d h %d min", hours, minutes)
		}
		return fmt.Sprintf("%d h", hours)
	}
	return fmt.Sprintf("%d min", minutes)
}

func stateColorStr(state string, noColor bool) string {
	if noColor {
		return ""
	}
	switch state {
	case "Working":
		return colorGreen
	case "Needs Input":
		return colorYellow
	case "Idle":
		return colorGray
	default:
		return colorGray
	}
}

func stateColor(state SessionState, noColor bool) string {
	if noColor {
		return ""
	}
	switch state {
	case Working:
		return colorGreen
	case NeedsInput:
		return colorYellow
	case Idle:
		return colorGray
	default:
		return colorGray
	}
}

func resetIfColor(noColor bool) string {
	if noColor {
		return ""
	}
	return colorReset
}