package tools

import (
	"context"
	"encoding/json"
	"fmt"

	"git.d-ma.be/mathias/gitea-mcp/internal/allowlist"
	"git.d-ma.be/mathias/gitea-mcp/internal/gitea"
	"git.d-ma.be/mathias/gitea-mcp/internal/registry"
)

type IssueEdit struct {
	c *gitea.Client
	a *allowlist.Allowlist
}

func NewIssueEdit(c *gitea.Client, a *allowlist.Allowlist) *IssueEdit {
	return &IssueEdit{c: c, a: a}
}

func (t *IssueEdit) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name: "issue_edit",
		Description: "Edit an existing issue's title and/or body. Only fields explicitly set are patched; " +
			"omitted fields are left untouched. Body is replaced verbatim (no identity footer) so edits are idempotent. " +
			"WARNING: body is a full replacement — to amend rather than clobber, read-modify-write " +
			"(fetch with issue_get, edit the text, send it back).",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"owner":{"type":"string"},
				"repo":{"type":"string"},
				"number":{"type":"integer","minimum":1},
				"title":{"type":"string","description":"New title. Omit to leave unchanged."},
				"body":{"type":"string","description":"New body, full replacement. Omit to leave unchanged."}
			},
			"required":["owner","repo","number"]
		}`),
	}
}

type issueEditArgs struct {
	Owner  string  `json:"owner"`
	Repo   string  `json:"repo"`
	Number int     `json:"number"`
	Title  *string `json:"title,omitempty"`
	Body   *string `json:"body,omitempty"`
}

func (t *IssueEdit) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args issueEditArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if err := t.a.Check(ctx, args.Owner); err != nil {
		return nil, err
	}
	if args.Number < 1 {
		return nil, fmt.Errorf("number is required: %w", gitea.ErrValidation)
	}
	if args.Title == nil && args.Body == nil {
		return nil, fmt.Errorf("at least one of title or body must be set: %w", gitea.ErrValidation)
	}

	iss, err := t.c.EditIssue(ctx, args.Owner, args.Repo, args.Number, gitea.EditIssueArgs{
		Title: args.Title,
		Body:  args.Body,
	})
	if err != nil {
		return nil, err
	}

	return textOK(map[string]any{
		"number":   iss.Number,
		"title":    iss.Title,
		"html_url": iss.HTMLURL,
		"state":    iss.State,
	})
}