package api

import (
	"io"

	"github.com/diamondburned/arikawa/discord" // for clarity
	d "github.com/diamondburned/arikawa/discord"
	"github.com/diamondburned/arikawa/internal/httputil"
)

const EndpointGuilds = Endpoint + "guilds/"

// https://discordapp.com/developers/docs/resources/guild#create-guild-json-params
type CreateGuildData struct {
	Name string `json:"name"`
	Icon Image  `json:"image,omitempty"`

	// package dc is just package discord
	Verification   d.Verification   `json:"verification_level"`
	Notification   d.Notification   `json:"default_message_notifications"`
	ExplicitFilter d.ExplicitFilter `json:"explicit_content_filter"`

	// [0] (First entry) is ALWAYS @everyone.
	Roles []discord.Role `json:"roles,omitempty"`

	// Voice only
	VoiceRegion string `json:"region,omitempty"`

	// Partial, id field is ignored. Usually only Name and Type are changed.
	Channels []discord.Channel `json:"channels,omitempty"`
}

func (c *Client) CreateGuild(data CreateGuildData) (*discord.Guild, error) {
	var g *discord.Guild
	return g, c.RequestJSON(&g, "POST", Endpoint+"guilds",
		httputil.WithJSONBody(c, data))
}

func (c *Client) Guild(guildID discord.Snowflake) (*discord.Guild, error) {
	var g *discord.Guild
	return g, c.RequestJSON(&g, "GET", EndpointGuilds+guildID.String())
}

// Guilds returns all guilds, automatically paginating. Be careful, as this
// method may abuse the API by requesting thousands or millions of guilds. For
// lower-level access, usee GuildsRange. Guilds returned have some fields
// filled only (ID, Name, Icon, Owner, Permissions).
func (c *Client) Guilds(max uint) ([]discord.Guild, error) {
	var guilds []discord.Guild
	var after discord.Snowflake = 0

	const hardLimit int = 100

	for fetch := uint(hardLimit); max > 0; fetch = uint(hardLimit) {
		if fetch > max {
			fetch = max
		}
		max -= fetch

		g, err := c.GuildsAfter(after, fetch)
		if err != nil {
			return guilds, err
		}
		guilds = append(guilds, g...)

		if len(g) < hardLimit {
			break
		}

		after = g[hardLimit-1].ID
	}

	return guilds, nil
}

// GuildsBefore fetches guilds. Check GuildsRange.
func (c *Client) GuildsBefore(
	before discord.Snowflake, limit uint) ([]discord.Guild, error) {

	return c.GuildsRange(before, 0, limit)
}

// GuildsAfter fetches guilds. Check GuildsRange.
func (c *Client) GuildsAfter(
	after discord.Snowflake, limit uint) ([]discord.Guild, error) {

	return c.GuildsRange(0, after, limit)
}

// GuildsRange fetches guilds. The limit is 1-100.
func (c *Client) GuildsRange(
	before, after discord.Snowflake, limit uint) ([]discord.Guild, error) {

	if limit == 0 {
		limit = 100
	}

	if limit > 100 {
		limit = 100
	}

	var param struct {
		Before discord.Snowflake `schema:"before"`
		After  discord.Snowflake `schema:"after"`

		Limit uint `schema:"limit"`
	}

	param.Before = before
	param.After = after
	param.Limit = limit

	var gs []discord.Guild
	return gs, c.RequestJSON(
		&gs, "GET",
		EndpointMe+"/guilds",
		httputil.WithSchema(c, param),
	)
}

func (c *Client) LeaveGuild(guildID discord.Snowflake) error {
	return c.FastRequest("DELETE", EndpointMe+"/guilds/"+guildID.String())
}

// https://discordapp.com/developers/docs/resources/guild#modify-guild-json-params
type ModifyGuildData struct {
	Name   string `json:"name,omitempty"`
	Region string `json:"region,omitempty"`
	Icon   Image  `json:"image,omitempty"`

	// package d is just package discord
	Verification   *d.Verification   `json:"verification_level,omitempty"`
	Notification   *d.Notification   `json:"default_message_notifications,omitempty"`
	ExplicitFilter *d.ExplicitFilter `json:"explicit_content_filter,omitempty"`

	AFKChannelID *d.Snowflake `json:"afk_channel_id,string,omitempty"`
	AFKTimeout   *d.Seconds   `json:"afk_timeout,omitempty"`

	OwnerID d.Snowflake `json:"owner_id,string,omitempty"`

	Splash Image `json:"splash,omitempty"`
	Banner Image `json:"banner,omitempty"`

	SystemChannelID d.Snowflake `json:"system_channel_id,string,omitempty"`
}

func (c *Client) ModifyGuild(
	guildID discord.Snowflake, data ModifyGuildData) (*discord.Guild, error) {

	var g *discord.Guild
	return g, c.RequestJSON(
		&g, "PATCH",
		EndpointGuilds+guildID.String(),
		httputil.WithJSONBody(c, data),
	)
}

func (c *Client) DeleteGuild(guildID discord.Snowflake) error {
	return c.FastRequest("DELETE", EndpointGuilds+guildID.String())
}

// GuildVoiceRegions is the same as /voice, but returns VIP ones as well if
// available.
func (c *Client) VoiceRegionsGuild(
	guildID discord.Snowflake) ([]discord.VoiceRegion, error) {

	var vrs []discord.VoiceRegion
	return vrs, c.RequestJSON(&vrs, "GET",
		EndpointGuilds+guildID.String()+"/regions")
}

// Integrations requires MANAGE_GUILD.
func (c *Client) Integrations(
	guildID discord.Snowflake) ([]discord.Integration, error) {

	var ints []discord.Integration
	return ints, c.RequestJSON(&ints, "GET",
		EndpointGuilds+guildID.String()+"/integrations")
}

// AttachIntegration requires MANAGE_GUILD.
func (c *Client) AttachIntegration(
	guildID, integrationID discord.Snowflake,
	integrationType discord.Service) error {

	var param struct {
		Type discord.Service   `json:"type"`
		ID   discord.Snowflake `json:"id"`
	}

	return c.FastRequest(
		"POST",
		EndpointGuilds+guildID.String()+"/integrations",
		httputil.WithJSONBody(c, param),
	)
}

// ModifyIntegration requires MANAGE_GUILD.
func (c *Client) ModifyIntegration(
	guildID, integrationID discord.Snowflake,
	expireBehavior, expireGracePeriod int, emoticons bool) error {

	var param struct {
		ExpireBehavior    int  `json:"expire_behavior"`
		ExpireGracePeriod int  `json:"expire_grace_period"`
		EnableEmoticons   bool `json:"enable_emoticons"`
	}

	param.ExpireBehavior = expireBehavior
	param.ExpireGracePeriod = expireGracePeriod
	param.EnableEmoticons = emoticons

	return c.FastRequest(
		"PATCH",
		EndpointGuilds+guildID.String()+
			"/integrations/"+integrationID.String(),
		httputil.WithSchema(c, param),
	)
}

func (c *Client) SyncIntegration(
	guildID, integrationID discord.Snowflake) error {

	return c.FastRequest("POST", EndpointGuilds+guildID.String()+
		"/integrations/"+integrationID.String()+"/sync")
}

func (c *Client) GuildEmbed(
	guildID discord.Snowflake) (*discord.GuildEmbed, error) {

	var ge *discord.GuildEmbed
	return ge, c.RequestJSON(&ge, "GET",
		EndpointGuilds+guildID.String()+"/embed")
}

// ModifyGuildEmbed should be used with care: if you still want the embed
// enabled, you need to set the Enabled boolean, even if it's already enabled.
// If you don't, JSON will default it to false.
func (c *Client) ModifyGuildEmbed(
	guildID discord.Snowflake,
	data discord.GuildEmbed) (*discord.GuildEmbed, error) {

	return &data, c.RequestJSON(&data, "PATCH",
		EndpointGuilds+guildID.String()+"/embed")
}

// GuildVanityURL returns *Invite, but only Code and Uses are filled. Requires
// MANAGE_GUILD.
func (c *Client) GuildVanityURL(
	guildID discord.Snowflake) (*discord.Invite, error) {

	var inv *discord.Invite
	return inv, c.RequestJSON(&inv, "GET",
		EndpointGuilds+guildID.String()+"/vanity-url")
}

type GuildImageType string

const (
	GuildShield  GuildImageType = "shield"
	GuildBanner1 GuildImageType = "banner1"
	GuildBanner2 GuildImageType = "banner2"
	GuildBanner3 GuildImageType = "banner3"
	GuildBanner4 GuildImageType = "banner4"
)

func (c *Client) GuildImageURL(
	guildID discord.Snowflake, img GuildImageType) string {

	return EndpointGuilds + guildID.String() +
		"/widget.png?style=" + string(img)
}

func (c *Client) GuildImage(
	guildID discord.Snowflake, img GuildImageType) (io.ReadCloser, error) {

	r, err := c.Request("GET", c.GuildImageURL(guildID, img))
	if err != nil {
		return nil, err
	}

	return r.Body, nil
}