// Copyright (c) 2026 Lark Technologies Pte. Ltd.
// SPDX-License-Identifier: MIT

// Package note owns the Note domain: querying note detail and the unified
// transcript by a known note_id. The vc domain locates a
// note_id from meeting context and delegates note-detail parsing here, so the
// parsing logic lives in exactly one place.
package note

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"github.com/larksuite/cli/errs"
	"github.com/larksuite/cli/internal/validate"
	"github.com/larksuite/cli/shortcuts/common"
)

// NoNoteReadPermissionCode is returned when the caller lacks read permission
// for the requested note.
const NoNoteReadPermissionCode = 121005

// ErrEmptyDetail identifies note detail responses that do not contain a note
// object. Callers should use errors.Is instead of matching the display message.
var ErrEmptyDetail = errors.New("note detail is empty")

// artifact_type enum from the note detail API.
const (
	artifactTypeMainDoc  = 1 // main note document
	artifactTypeVerbatim = 2 // verbatim transcript
)

// note_display_type enum (i32) from the note detail API. Surfaced to callers as
// a stable string so Agents route on a name, not a magic number.
const (
	displayTypeNormal  = 1
	displayTypeUnified = 2
)

// Detail is the parsed note detail shared by `note +detail` and `vc +notes`.
type Detail struct {
	NoteID           string
	CreatorID        string
	CreateTime       string
	DisplayType      string // unknown | normal | unified
	NoteDocToken     string
	VerbatimDocToken string
	SharedDocTokens  []string
}

// FetchDetail queries GET /open-apis/vc/v1/notes/{note_id} and parses the note
// object. API errors are returned as typed errs.* values so callers can enrich
// user guidance without downgrading the envelope.
func FetchDetail(_ context.Context, runtime *common.RuntimeContext, noteID string) (*Detail, error) {
	data, err := runtime.DoAPIJSONTyped(http.MethodGet, fmt.Sprintf("/open-apis/vc/v1/notes/%s", validate.EncodePathSegment(noteID)), nil, nil)
	if err != nil {
		return nil, err
	}
	noteObj, _ := data["note"].(map[string]any)
	if noteObj == nil {
		return nil, errs.NewInternalError(errs.SubtypeInvalidResponse, "note detail is empty").WithCause(ErrEmptyDetail)
	}
	noteDoc, verbatimDoc := extractArtifactTokens(common.GetSlice(noteObj, "artifacts"))
	return &Detail{
		NoteID:           noteID,
		CreatorID:        common.GetString(noteObj, "creator_id"),
		CreateTime:       common.FormatTime(noteObj["create_time"]),
		DisplayType:      displayTypeString(displayTypeValue(noteObj)),
		NoteDocToken:     noteDoc,
		VerbatimDocToken: verbatimDoc,
		SharedDocTokens:  extractDocTokens(common.GetSlice(noteObj, "references")),
	}, nil
}

// ToMap renders the detail as the field map consumed by `vc +notes`, keeping
// the historical key set (shared_doc_tokens omitted when empty) and adding the
// note_id / note_display_type fields.
func (d *Detail) ToMap() map[string]any {
	m := map[string]any{
		"note_id":            d.NoteID,
		"note_display_type":  d.DisplayType,
		"creator_id":         d.CreatorID,
		"create_time":        d.CreateTime,
		"note_doc_token":     d.NoteDocToken,
		"verbatim_doc_token": d.VerbatimDocToken,
	}
	if len(d.SharedDocTokens) > 0 {
		m["shared_doc_tokens"] = d.SharedDocTokens
	}
	return m
}

// displayTypeValue reads the display-type field, tolerating either the
// documented note_display_type key or a bare display_type fallback.
func displayTypeValue(note map[string]any) any {
	if v, ok := note["note_display_type"]; ok {
		return v
	}
	return note["display_type"]
}

func displayTypeString(v any) string {
	switch parseLooseInt(v) {
	case displayTypeNormal:
		return "normal"
	case displayTypeUnified:
		return "unified"
	default:
		return "unknown"
	}
}

// extractArtifactTokens picks main-doc and verbatim-doc tokens from artifacts.
func extractArtifactTokens(artifacts []any) (noteDoc, verbatimDoc string) {
	for _, a := range artifacts {
		artifact, _ := a.(map[string]any)
		if artifact == nil {
			continue
		}
		docToken, _ := artifact["doc_token"].(string)
		switch parseLooseInt(artifact["artifact_type"]) {
		case artifactTypeMainDoc:
			noteDoc = docToken
		case artifactTypeVerbatim:
			verbatimDoc = docToken
		}
	}
	return
}

// extractDocTokens collects doc_token values from a list of reference objects.
func extractDocTokens(refs []any) []string {
	var tokens []string
	for _, s := range refs {
		source, _ := s.(map[string]any)
		if source == nil {
			continue
		}
		if docToken, _ := source["doc_token"].(string); docToken != "" {
			tokens = append(tokens, docToken)
		}
	}
	return tokens
}

// parseLooseInt extracts an int from the varying JSON number representations
// DoAPIJSON may yield (json.Number, float64, or int).
func parseLooseInt(v any) int {
	switch n := v.(type) {
	case json.Number:
		i, _ := n.Int64()
		return int(i)
	case float64:
		// Reject fractional values: truncating 1.9 to 1 would silently coerce
		// a malformed enum into a valid one.
		if n != float64(int64(n)) {
			return 0
		}
		return int(n)
	case int:
		return n
	default:
		return 0
	}
}

// parseLooseCursorID extracts a positive cursor as a string. String cursors are
// preferred because large JSON numbers lose precision when decoded into any.
func parseLooseCursorID(v any) (string, bool) {
	switch n := v.(type) {
	case string:
		s := strings.TrimSpace(n)
		if s == "" || s == "0" {
			return "", false
		}
		return s, true
	case json.Number:
		i, err := n.Int64()
		if err != nil || i <= 0 {
			return "", false
		}
		return strconv.FormatInt(i, 10), true
	case float64:
		// encoding/json decodes numbers in map[string]any as float64. Accept
		// only values that can round-trip safely as an integer cursor.
		const maxSafeJSONInteger = 1<<53 - 1
		if n <= 0 || n != float64(int64(n)) || n > maxSafeJSONInteger {
			return "", false
		}
		return strconv.FormatInt(int64(n), 10), true
	case int64:
		if n <= 0 {
			return "", false
		}
		return strconv.FormatInt(n, 10), true
	case int:
		if n <= 0 {
			return "", false
		}
		return strconv.Itoa(n), true
	default:
		return "", false
	}
}