package ui

import (
	"fmt"
	"strings"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"

	"github.com/atridad/gitea-wrapped/pkg/models"
)

type ReportScreen struct {
	stats    *models.UserStats
	page     int
	maxPages int
}

func NewReportScreen(stats *models.UserStats) *ReportScreen {
	return &ReportScreen{
		stats:    stats,
		page:     0,
		maxPages: 3,
	}
}

func (rs *ReportScreen) Init() tea.Cmd {
	return nil
}

func (rs *ReportScreen) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c":
			return rs, tea.Quit
		case "right", "l", "n":
			if rs.page < rs.maxPages-1 {
				rs.page++
			}
		case "left", "h", "p":
			if rs.page > 0 {
				rs.page--
			}
		}
	}
	return rs, nil
}

func (rs *ReportScreen) View() string {
	header := lipgloss.NewStyle().
		Foreground(lipgloss.Color("212")).
		Bold(true).
		Render(fmt.Sprintf("Gitea Wrapped %d", 2026)) + "\n"

	var content string
	switch rs.page {
	case 0:
		content = rs.renderOverviewPage()
	case 1:
		content = rs.renderLanguagesPage()
	case 2:
		content = rs.renderActivityPage()
	}

	footer := lipgloss.NewStyle().
		Foreground(lipgloss.Color("8")).
		Render(fmt.Sprintf("Page %d/%d | ← → to navigate | q to quit", rs.page+1, rs.maxPages))

	return header + "\n" + content + "\n\n" + footer
}

func (rs *ReportScreen) renderOverviewPage() string {
	var s strings.Builder

	s.WriteString(lipgloss.NewStyle().
		Foreground(lipgloss.Color("14")).
		Bold(true).
		Render("Your 2026 Overview") + "\n\n")

	s.WriteString(fmt.Sprintf("Username: %s\n", rs.stats.Username))
	s.WriteString(fmt.Sprintf("Total Commits: %d\n", rs.stats.TotalCommits))
	s.WriteString(fmt.Sprintf("Total Repositories: %d\n", rs.stats.TotalRepositories))
	s.WriteString(fmt.Sprintf("Average Commits/Day: %.2f\n", rs.stats.AverageCommitsPerDay))
	s.WriteString(fmt.Sprintf("Most Active Day: %s\n", rs.stats.MostActiveDay))
	s.WriteString(fmt.Sprintf("Most Active Month: %s\n", rs.stats.MostActiveMonth))

	s.WriteString("\nTop Repositories:\n")
	for i, repo := range rs.stats.TopRepositories {
		if i >= 5 {
			break
		}
		s.WriteString(fmt.Sprintf("  %d. %s\n", i+1, repo.Name))
	}

	return s.String()
}

func (rs *ReportScreen) renderLanguagesPage() string {
	var s strings.Builder

	s.WriteString(lipgloss.NewStyle().
		Foreground(lipgloss.Color("14")).
		Bold(true).
		Render("Languages You Love") + "\n\n")

	if len(rs.stats.Languages) == 0 {
		s.WriteString("No language data available.\n")
		return s.String()
	}

	maxLength := 30
	maxCount := 0
	for _, lang := range rs.stats.Languages {
		if lang.Count > maxCount {
			maxCount = lang.Count
		}
	}

	for i, lang := range rs.stats.Languages {
		if i >= 10 {
			break
		}

		barLength := int(float64(lang.Count) / float64(maxCount) * float64(maxLength))
		bar := strings.Repeat("█", barLength) + strings.Repeat("░", maxLength-barLength)
		s.WriteString(fmt.Sprintf("%-12s %s %d (%.1f%%)\n", lang.Language, bar, lang.Count, lang.Percent))
	}

	return s.String()
}

func (rs *ReportScreen) renderActivityPage() string {
	var s strings.Builder

	s.WriteString(lipgloss.NewStyle().
		Foreground(lipgloss.Color("14")).
		Bold(true).
		Render("Your Activity Patterns") + "\n\n")

	s.WriteString("Most Active Days of the Week:\n")
	if len(rs.stats.CommitsByWeekday) > 0 {
		maxCount := rs.stats.CommitsByWeekday[0].Count
		for i, day := range rs.stats.CommitsByWeekday {
			if i >= 7 {
				break
			}
			barLength := int(float64(day.Count) / float64(maxCount) * 20)
			bar := strings.Repeat("█", barLength) + strings.Repeat("░", 20-barLength)
			s.WriteString(fmt.Sprintf("%-12s %s %d\n", day.Day, bar, day.Count))
		}
	} else {
		s.WriteString("No weekday data available.\n")
	}

	s.WriteString("\nMost Active Months:\n")
	if len(rs.stats.CommitsByMonth) > 0 {
		maxCount := rs.stats.CommitsByMonth[0].Count
		for i, month := range rs.stats.CommitsByMonth {
			if i >= 12 {
				break
			}
			barLength := int(float64(month.Count) / float64(maxCount) * 20)
			bar := strings.Repeat("█", barLength) + strings.Repeat("░", 20-barLength)
			monthStr := month.Date.Format("Jan 2006")
			s.WriteString(fmt.Sprintf("%-12s %s %d\n", monthStr, bar, month.Count))
		}
	} else {
		s.WriteString("No monthly data available.\n")
	}

	return s.String()
}