package public

import (
	"context"
	"strconv"
	"strings"

	"velox-bot/internal/commands/projects/shared"
	"velox-bot/internal/db/services"

	"github.com/bwmarrin/discordgo"
)

var Projects = &discordgo.ApplicationCommand{
	Name:        "projects",
	Description: "Manage and list ongoing projects",
	Options: []*discordgo.ApplicationCommandOption{
		{
			Type:        discordgo.ApplicationCommandOptionSubCommand,
			Name:        "list",
			Description: "List active projects with creators and helpers",
		},
		{
			Type:        discordgo.ApplicationCommandOptionSubCommand,
			Name:        "create",
			Description: "Create a new active project",
			Options: []*discordgo.ApplicationCommandOption{
				{
					Type:        discordgo.ApplicationCommandOptionString,
					Name:        "name",
					Description: "Project name",
					Required:    true,
				},
				{
					Type:        discordgo.ApplicationCommandOptionString,
					Name:        "description",
					Description: "Short description (optional)",
					Required:    false,
				},
			},
		},
		{
			Type:        discordgo.ApplicationCommandOptionSubCommand,
			Name:        "add-helper",
			Description: "Add a helper to an existing project",
			Options: []*discordgo.ApplicationCommandOption{
				{
					Type:        discordgo.ApplicationCommandOptionInteger,
					Name:        "project-id",
					Description: "ID of the project",
					Required:    true,
				},
				{
					Type:        discordgo.ApplicationCommandOptionUser,
					Name:        "user",
					Description: "User to add as helper",
					Required:    true,
				},
			},
		},
	},
}

func ProjectsHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
	if !shared.RequireGuild(s, i) || !shared.RequireProjectsService(s, i) {
		return
	}

	data := i.ApplicationCommandData()
	if len(data.Options) == 0 {
		handleList(s, i)
		return
	}

	switch data.Options[0].Name {
	case "list":
		handleList(s, i)
	case "create":
		handleCreate(s, i)
	case "add-helper":
		handleAddHelper(s, i)
	default:
		shared.RespondEphemeral(s, i, "Unknown subcommand.")
	}
}

func handleList(s *discordgo.Session, i *discordgo.InteractionCreate) {
	guildID, ok := shared.ParseGuildID(s, i)
	if !ok {
		return
	}

	const limit = 25
	items, err := services.Global.Projects.ListActiveWithMembers(context.Background(), guildID, limit)
	if err != nil {
		shared.RespondEphemeral(s, i, "Failed to load projects.")
		return
	}
	if len(items) == 0 {
		shared.RespondEphemeral(s, i, "There are no active projects at the moment.")
		return
	}

	embed := &discordgo.MessageEmbed{
		Title:       "Active projects",
		Description: "",
		Color:       0x00bcd4,
	}

	for _, item := range items {
		if item == nil || item.Project == nil {
			continue
		}
		p := item.Project
		name := p.Name
		if name == "" {
			name = "Unnamed project"
		}
		creatorMention := mentionUser(item.Creator)

		var helpersMentions []string
		for _, h := range item.Helpers {
			helpersMentions = append(helpersMentions, mentionUser(h))
		}
		helpersText := "None"
		if len(helpersMentions) > 0 {
			helpersText = strings.Join(helpersMentions, ", ")
		}

		desc := "**Creator:** " + creatorMention + "\n" +
			"**Helpers:** " + helpersText
		if p.Description != "" {
			desc += "\n" + p.Description
		}

		embed.Fields = append(embed.Fields, &discordgo.MessageEmbedField{
			Name:  name,
			Value: desc,
		})
	}

	_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
		Type: discordgo.InteractionResponseChannelMessageWithSource,
		Data: &discordgo.InteractionResponseData{
			Embeds: []*discordgo.MessageEmbed{embed},
		},
	})
}

func mentionUser(id int64) string {
	if id == 0 {
		return "Unknown"
	}
	return "<@" + strconv.FormatInt(id, 10) + ">"
}

func handleCreate(s *discordgo.Session, i *discordgo.InteractionCreate) {
	if !shared.RequireManageGuild(s, i) {
		return
	}

	guildID, ok := shared.ParseGuildID(s, i)
	if !ok {
		return
	}
	if i.Member == nil || i.Member.User == nil {
		shared.RespondEphemeral(s, i, "Missing member info.")
		return
	}

	data := i.ApplicationCommandData()
	if len(data.Options) == 0 {
		shared.RespondEphemeral(s, i, "Missing options.")
		return
	}
	opt := data.Options[0]

	var name, description string
	for _, o := range opt.Options {
		switch o.Name {
		case "name":
			name = o.StringValue()
		case "description":
			description = o.StringValue()
		}
	}
	if strings.TrimSpace(name) == "" {
		shared.RespondEphemeral(s, i, "Project name cannot be empty.")
		return
	}

	creatorID, err := strconv.ParseInt(i.Member.User.ID, 10, 64)
	if err != nil {
		shared.RespondEphemeral(s, i, "Invalid user ID.")
		return
	}

	id, err := services.Global.Projects.CreateProject(context.Background(), guildID, creatorID, name, description)
	if err != nil {
		shared.RespondEphemeral(s, i, "Failed to create project.")
		return
	}

	shared.RespondEphemeral(s, i, "Created project **"+name+"** with ID `"+strconv.FormatInt(id, 10)+"`.")
}

func handleAddHelper(s *discordgo.Session, i *discordgo.InteractionCreate) {
	if !shared.RequireManageGuild(s, i) {
		return
	}

	guildID, ok := shared.ParseGuildID(s, i)
	if !ok {
		return
	}

	data := i.ApplicationCommandData()
	if len(data.Options) == 0 {
		shared.RespondEphemeral(s, i, "Missing options.")
		return
	}
	opt := data.Options[0]

	var projectID int64
	var userID string
	for _, o := range opt.Options {
		switch o.Name {
		case "project-id":
			projectID = o.IntValue()
		case "user":
			if u := o.UserValue(s); u != nil {
				userID = u.ID
			}
		}
	}
	if projectID <= 0 {
		shared.RespondEphemeral(s, i, "Invalid project ID.")
		return
	}
	if userID == "" {
		shared.RespondEphemeral(s, i, "Invalid user.")
		return
	}

	exists, err := services.Global.Projects.ProjectExistsInGuild(context.Background(), guildID, projectID)
	if err != nil {
		shared.RespondEphemeral(s, i, "Failed to load project.")
		return
	}
	if !exists {
		shared.RespondEphemeral(s, i, "Project `"+strconv.FormatInt(projectID, 10)+"` not found in this server.")
		return
	}

	userID64, err := strconv.ParseInt(userID, 10, 64)
	if err != nil {
		shared.RespondEphemeral(s, i, "Invalid user ID.")
		return
	}

	if err := services.Global.Projects.AddHelper(context.Background(), projectID, userID64); err != nil {
		shared.RespondEphemeral(s, i, "Failed to add helper to project. ("+err.Error()+")")
		return
	}

	shared.RespondEphemeral(s, i, "Added <@"+userID+"> as helper to project `"+strconv.FormatInt(projectID, 10)+"`.")
}