// SPDX-FileCopyrightText: Amolith <amolith@secluded.site>
//
// SPDX-License-Identifier: AGPL-3.0-or-later

// Package journal provides MCP tools for Lunatask journal operations.
package journal

import (
	"context"

	"git.secluded.site/go-lunatask"
	"git.secluded.site/lune/internal/dateutil"
	"git.secluded.site/lune/internal/mcp/shared"
	"github.com/modelcontextprotocol/go-sdk/mcp"
)

// CreateToolName is the name of the create journal entry tool.
const CreateToolName = "add_journal_entry"

// CreateToolDescription describes the create journal entry tool for LLMs.
const CreateToolDescription = `Creates a journal entry in Lunatask for daily reflection.

Optional:
- content: Markdown content for the entry
- name: Entry title (defaults to weekday name if omitted)
- date: Entry date (YYYY-MM-DD or natural language, default: today)

Entries are date-keyed. If no date is provided, uses today.
Content supports Markdown formatting.

Common uses:
- End-of-day summaries
- Reflection on completed work
- Recording thoughts or learnings`

// CreateInput is the input schema for creating a journal entry.
type CreateInput struct {
	Content *string `json:"content,omitempty"`
	Name    *string `json:"name,omitempty"`
	Date    *string `json:"date,omitempty"`
}

// CreateOutput is the output schema for creating a journal entry.
type CreateOutput struct {
	ID   string `json:"id"`
	Date string `json:"date"`
}

// Handler handles journal-related MCP tool requests.
type Handler struct {
	client *lunatask.Client
}

// NewHandler creates a new journal handler.
func NewHandler(accessToken string) *Handler {
	return &Handler{
		client: lunatask.NewClient(accessToken, lunatask.UserAgent("lune-mcp/1.0")),
	}
}

// HandleCreate creates a new journal entry.
func (h *Handler) HandleCreate(
	ctx context.Context,
	_ *mcp.CallToolRequest,
	input CreateInput,
) (*mcp.CallToolResult, CreateOutput, error) {
	dateStr := ""
	if input.Date != nil {
		dateStr = *input.Date
	}

	date, err := dateutil.Parse(dateStr)
	if err != nil {
		return shared.ErrorResult(err.Error()), CreateOutput{}, nil
	}

	builder := h.client.NewJournalEntry(date)

	if input.Content != nil {
		builder.WithContent(*input.Content)
	}

	if input.Name != nil {
		builder.WithName(*input.Name)
	}

	entry, err := builder.Create(ctx)
	if err != nil {
		return shared.ErrorResult(err.Error()), CreateOutput{}, nil
	}

	formattedDate := date.Format("2006-01-02")

	return &mcp.CallToolResult{
			Content: []mcp.Content{&mcp.TextContent{
				Text: "Journal entry created for " + formattedDate,
			}},
		}, CreateOutput{
			ID:   entry.ID,
			Date: formattedDate,
		}, nil
}