package kook

// This file adds the KOOK guild/channel/message admin-REST surface (design/17
// §2), sharing the authenticated httpclient. Only read listing plus a single
// controlled "test send" write are exposed; the test send reuses the channel
// message endpoint so the panel can verify the bot can post.

import (
	"context"
	"encoding/json"
	"fmt"
	"net/url"
	"strconv"
)

// Public admin-REST endpoints (relative to the KOOK API root).
const (
	guildListPath       = "/guild/list"
	guildUserListPath   = "/guild/user-list"
	channelListPath     = "/channel/list"
	channelMsgsPath     = "/message/list"
	guildChannelMsgPath = "/message/create"
)

// Guild is one server from GET /guild/list.
type Guild struct {
	ID    string `json:"id"`
	Name  string `json:"name"`
	Icon  string `json:"icon"`
	Topic string `json:"topic"`
}

// Channel is one channel from GET /channel/list.
type Channel struct {
	ID         string `json:"id"`
	UserID     string `json:"user_id"`
	GuildID    string `json:"guild_id"`
	ParentID   string `json:"parent_id"`
	Name       string `json:"name"`
	Type       int    `json:"type"`
	Level      int    `json:"level"`
	IsCategory bool   `json:"is_category"`
}

// GuildUser is one member from GET /guild/user-list.
type GuildUser struct {
	UserID   string `json:"user_id"`
	Username string `json:"username"`
	Nickname string `json:"nickname"`
	Avatar   string `json:"avatar"`
	Online   bool   `json:"online"`
	Bot      bool   `json:"bot"`
}

// ChannelMessage is one channel message from GET /message/list.
type ChannelMessage struct {
	ID         string `json:"id"`
	Type       int    `json:"type"`
	Content    string `json:"content"`
	AuthorID   string `json:"author_id"`
	AuthorName string `json:"author_name"`
	CreateAt   int64  `json:"create_at"`
}

// TestMessageResult is the POST /message/create response.
type TestMessageResult struct {
	MsgID        string `json:"msg_id"`
	MsgTimestamp int64  `json:"msg_timestamp"`
}

// ListGuilds returns the servers the bot has joined.
func (a *Adapter) ListGuilds(ctx context.Context, page, pageSize int) ([]Guild, error) {
	raw, err := a.http.GetJSON(ctx, guildListPath, pageQuery(page, pageSize))
	if err != nil {
		return nil, fmt.Errorf("kook: list guilds: %w", err)
	}
	var data rawItemList
	if err := json.Unmarshal(raw, &data); err != nil {
		return nil, fmt.Errorf("kook: decode guild list: %w", err)
	}
	out := make([]Guild, 0, len(data.Items))
	for _, it := range data.Items {
		item, ok := asMap(it)
		if !ok {
			continue
		}
		out = append(out, Guild{
			ID:    str(item, "id"),
			Name:  str(item, "name"),
			Icon:  str(item, "icon"),
			Topic: str(item, "topic"),
		})
	}
	return out, nil
}

// ListChannelMsgs returns the recent messages of a channel (GET /message/list).
// targetID is the channel id; it is required per the KOOK contract.
func (a *Adapter) ListChannelMsgs(ctx context.Context, targetID string, pageSize int) ([]ChannelMessage, error) {
	q := url.Values{"target_id": {targetID}}
	if pageSize > 0 {
		q.Set("page_size", strconv.Itoa(pageSize))
	}
	raw, err := a.http.GetJSON(ctx, channelMsgsPath, q)
	if err != nil {
		return nil, fmt.Errorf("kook: list channel messages: %w", err)
	}
	var data rawItemList
	if err := json.Unmarshal(raw, &data); err != nil {
		return nil, fmt.Errorf("kook: decode channel message list: %w", err)
	}
	out := make([]ChannelMessage, 0, len(data.Items))
	for _, it := range data.Items {
		item, ok := asMap(it)
		if !ok {
			continue
		}
		authorID := str(item, "author_id")
		authorName := ""
		if author, ok := asMap(item["author"]); ok {
			authorID = firstNonEmpty(authorID, str(author, "id"))
			authorName = firstNonEmpty(str(author, "nickname"), str(author, "username"))
		}
		out = append(out, ChannelMessage{
			ID:         str(item, "id"),
			Type:       intOf(item["type"]),
			Content:    str(item, "content"),
			AuthorID:   authorID,
			AuthorName: authorName,
			CreateAt:   int64Of(item["create_at"]),
		})
	}
	return out, nil
}

// ListGuildChannels returns the channels of a guild. typ 0 = text (KOOK
// default), 2 = voice, -1 = all types. (Named ListGuildChannels because the
// PlatformAdapter contract already reserves ListChannels.)
func (a *Adapter) ListGuildChannels(ctx context.Context, guildID string, typ int) ([]Channel, error) {
	q := url.Values{"guild_id": {guildID}}
	if typ >= 0 {
		q.Set("type", strconv.Itoa(typ))
	}
	raw, err := a.http.GetJSON(ctx, channelListPath, q)
	if err != nil {
		return nil, fmt.Errorf("kook: list channels: %w", err)
	}
	var data rawItemList
	if err := json.Unmarshal(raw, &data); err != nil {
		return nil, fmt.Errorf("kook: decode channel list: %w", err)
	}
	out := make([]Channel, 0, len(data.Items))
	for _, it := range data.Items {
		item, ok := asMap(it)
		if !ok {
			continue
		}
		out = append(out, Channel{
			ID:         str(item, "id"),
			UserID:     str(item, "user_id"),
			GuildID:    str(item, "guild_id"),
			ParentID:   str(item, "parent_id"),
			Name:       str(item, "name"),
			Type:       intOf(item["type"]),
			Level:      intOf(item["level"]),
			IsCategory: boolOf(item["is_category"]),
		})
	}
	return out, nil
}

// ListGuildUsers returns the members of a guild.
func (a *Adapter) ListGuildUsers(ctx context.Context, guildID string, page, pageSize int) ([]GuildUser, error) {
	q := pageQuery(page, pageSize)
	q.Set("guild_id", guildID)
	raw, err := a.http.GetJSON(ctx, guildUserListPath, q)
	if err != nil {
		return nil, fmt.Errorf("kook: list guild users: %w", err)
	}
	var data rawItemList
	if err := json.Unmarshal(raw, &data); err != nil {
		return nil, fmt.Errorf("kook: decode guild user list: %w", err)
	}
	out := make([]GuildUser, 0, len(data.Items))
	for _, it := range data.Items {
		item, ok := asMap(it)
		if !ok {
			continue
		}
		out = append(out, GuildUser{
			UserID:   firstNonEmpty(str(item, "id"), str(item, "user_id")),
			Username: str(item, "username"),
			Nickname: str(item, "nickname"),
			Avatar:   str(item, "avatar"),
			Online:   boolOf(item["online"]),
			Bot:      boolOf(item["bot"]),
		})
	}
	return out, nil
}

// SendTestMessage posts one kmarkdown message to targetID (a channel id) and
// returns the server-assigned message id, so the panel can verify the bot can
// reach the channel. The token is never logged.
func (a *Adapter) SendTestMessage(ctx context.Context, targetID, content string) (TestMessageResult, error) {
	if targetID == "" {
		return TestMessageResult{}, fmt.Errorf("kook: %w", ErrNoChatTarget)
	}
	if content == "" {
		return TestMessageResult{}, fmt.Errorf("kook: test message content empty")
	}
	raw, err := a.http.DoJSON(ctx, "POST", guildChannelMsgPath, kookPostRequest{
		Type:     kindKMarkdown,
		TargetID: targetID,
		Content:  content,
	})
	if err != nil {
		return TestMessageResult{}, fmt.Errorf("kook: send test message: %w", err)
	}
	var res TestMessageResult
	if err := json.Unmarshal(raw, &res); err != nil {
		return TestMessageResult{}, fmt.Errorf("kook: decode test message: %w", err)
	}
	return res, nil
}

// rawItemList is the generic paginated items payload shared by guild/channel/
// message/user-* list endpoints.
type rawItemList struct {
	Items []json.RawMessage `json:"items"`
}

// asMap decodes an object value into a map; ok=false for non-object values. It
// accepts both the raw JSON of a list item and an already-decoded any map, so
// nested objects (e.g. a message's author) parse the same way.
func asMap(v any) (map[string]any, bool) {
	switch m := v.(type) {
	case map[string]any:
		return m, true
	case json.RawMessage:
		var out map[string]any
		if len(m) == 0 {
			return nil, false
		}
		if err := json.Unmarshal(m, &out); err != nil {
			return nil, false
		}
		return out, true
	default:
		return nil, false
	}
}

func str(m map[string]any, key string) string {
	if v, ok := m[key].(string); ok {
		return v
	}
	return ""
}

func intOf(v any) int {
	switch n := v.(type) {
	case float64:
		return int(n)
	case int:
		return n
	default:
		return 0
	}
}

func int64Of(v any) int64 {
	switch n := v.(type) {
	case float64:
		return int64(n)
	case int:
		return int64(n)
	default:
		return 0
	}
}

func boolOf(v any) bool {
	switch b := v.(type) {
	case bool:
		return b
	case float64:
		return b != 0
	default:
		return false
	}
}

func firstNonEmpty(a, b string) string {
	if a != "" {
		return a
	}
	return b
}