package domain

import (
	"fmt"
	"os"

	"redmine_tree/domain/model"
)

// UI represents the user interface output.
type UI struct {
	// You can add fields here for more advanced UI customization if needed,
	// e.g., output writer (os.Stdout, os.Stderr), log levels, etc.
}

// NewUI creates and returns a new UI instance.
func NewUI() *UI {
	return &UI{}
}

// PrintError prints an error message to stderr and exits.
func (ui *UI) PrintError(format string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, format, a...)
	os.Exit(1)
}

// Printf prints a formatted message to stdout.
func (ui *UI) Printf(format string, a ...interface{}) {
	fmt.Printf(format, a...)
}

// Println prints a message to stdout with a newline.
func (ui *UI) Println(a ...interface{}) {
	fmt.Println(a...)
}

// PrintProjects lists projects to stdout.
func (ui *UI) PrintProjects(projects []model.Project) {
	ui.Printf("No project ID provided. Listing all available projects:\n\n")
	if len(projects) == 0 {
		ui.Println("No projects found.")
	} else {
		for _, p := range projects {
			ui.Printf("  #%d %s\n", p.ID, p.Name)
		}
	}
}

// PrintUsage prints the application usage message to stderr and exits.
func (ui *UI) PrintUsage(appName string) {
	ui.Printf("Usage: %s <project-id>\n", appName)
	ui.Printf("       REDMINE_URL and REDMINE_TOKEN must be set in .env, as environment variables, or in ~/.redmine-tree.json.\n")
	ui.Printf("Example: REDMINE_URL=https://redmine.example.com REDMINE_TOKEN=abc123 %s my-project\n", appName)
	ui.Printf("Or: %s my-project (if REDMINE_URL, REDMINE_TOKEN are in .env or ~/.redmine-tree.json)\n", appName)
	os.Exit(1)
}

// PrintFetchingProjectDetails prints the message when fetching project details.
func (ui *UI) PrintFetchingProjectDetails(projectName, projectID string) {
	ui.Printf("Fetching issues for project: %s (%s)\n\n", projectName, projectID)
}

// PrintTotalIssuesFetched prints the total number of issues fetched.
func (ui *UI) PrintTotalIssuesFetched(count int) {
	ui.Printf("Total issues fetched: %d\n\n", count)
}

// PrintIssueTreeHeader prints the header for the issue tree.
func (ui *UI) PrintIssueTreeHeader(rootCount int) {
	ui.Printf("Issue tree (%d root issues):\n\n", rootCount)
}

// PrintSummary prints the summary of issues.
func (ui *UI) PrintSummary(totalIssues, rootIssues int) {
	ui.Printf("\n--- Summary ---\n")
	ui.Printf("Total issues : %d\n", totalIssues)
	ui.Printf("Root issues  : %d\n", rootIssues)
}