package tools

import (
	"context"
	"encoding/json"

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

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

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

func (t *PRList) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "pr_list",
		Description: "List pull requests. state: open (default), closed, or all. Optionally filter by head branch.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"owner":{"type":"string"},
				"name":{"type":"string"},
				"state":{"type":"string","enum":["open","closed","all"]},
				"head":{"type":"string"},
				"page":{"type":"integer","minimum":1},
				"limit":{"type":"integer","minimum":1,"maximum":50}
			},
			"required":["owner","name"]
		}`),
	}
}

type prListArgs struct {
	Owner string `json:"owner"`
	Name  string `json:"name"`
	State string `json:"state"`
	Head  string `json:"head"`
	Page  int    `json:"page"`
	Limit int    `json:"limit"`
}

func (t *PRList) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args prListArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if err := t.a.Check(args.Owner); err != nil {
		return nil, err
	}
	state := args.State
	if state == "" {
		state = "open"
	}

	prs, err := t.c.ListPullRequests(ctx, args.Owner, args.Name, state, args.Head, args.Page, capLimit(args.Limit, 30))
	if err != nil {
		return nil, err
	}

	result := make([]map[string]any, len(prs))
	for i, pr := range prs {
		result[i] = map[string]any{
			"number":      pr.Number,
			"title":       pr.Title,
			"state":       pr.State,
			"head_branch": pr.Head.Ref,
			"base_branch": pr.Base.Ref,
			"draft":       pr.Draft,
			"html_url":    pr.HTMLURL,
		}
	}
	return textOK(result)
}