package wiki

import (
	"fmt"
	"net/url"
	"strconv"
)

// Section represents a section of a wiki page.
type Section struct {
	Index   string `json:"index"`
	Level   string `json:"level"`
	Line    string `json:"line"`
	Number  string `json:"number"`
	Anchor  string `json:"anchor"`
}

// ParsedPage contains the result of parsing a wiki page.
type ParsedPage struct {
	Title    string    `json:"title"`
	PageID   int       `json:"pageid"`
	Wikitext string    // Raw wikitext of the page or section
	HTML     string    // Rendered HTML
	Sections []Section // Table of contents
}

// parseResponse wraps the API response for action=parse.
type parseResponse struct {
	Parse struct {
		Title    string    `json:"title"`
		PageID   int       `json:"pageid"`
		Wikitext struct {
			Content string `json:"*"`
		} `json:"wikitext"`
		Text struct {
			Content string `json:"*"`
		} `json:"text"`
		Sections []Section `json:"sections"`
	} `json:"parse"`
	Error *struct {
		Code string `json:"code"`
		Info string `json:"info"`
	} `json:"error"`
}

// GetPage fetches the full wikitext and section list for a page.
func (c *Client) GetPage(title string) (*ParsedPage, error) {
	params := url.Values{
		"action":    {"parse"},
		"page":      {title},
		"prop":      {"wikitext|sections"},
		"redirects": {"1"},
	}

	var resp parseResponse
	if err := c.get(params, &resp); err != nil {
		return nil, err
	}

	if resp.Error != nil {
		return nil, fmt.Errorf("wiki API error: %s — %s", resp.Error.Code, resp.Error.Info)
	}

	return &ParsedPage{
		Title:    resp.Parse.Title,
		PageID:   resp.Parse.PageID,
		Wikitext: resp.Parse.Wikitext.Content,
		Sections: resp.Parse.Sections,
	}, nil
}

// GetPageSection fetches the wikitext for a specific section of a page.
func (c *Client) GetPageSection(title string, sectionIndex int) (*ParsedPage, error) {
	params := url.Values{
		"action":  {"parse"},
		"page":    {title},
		"prop":    {"wikitext"},
		"section": {strconv.Itoa(sectionIndex)},
	}

	var resp parseResponse
	if err := c.get(params, &resp); err != nil {
		return nil, err
	}

	if resp.Error != nil {
		return nil, fmt.Errorf("wiki API error: %s — %s", resp.Error.Code, resp.Error.Info)
	}

	return &ParsedPage{
		Title:    resp.Parse.Title,
		PageID:   resp.Parse.PageID,
		Wikitext: resp.Parse.Wikitext.Content,
	}, nil
}

// GetPageHTML fetches the rendered HTML for a page.
func (c *Client) GetPageHTML(title string) (*ParsedPage, error) {
	params := url.Values{
		"action": {"parse"},
		"page":   {title},
		"prop":   {"text|sections"},
	}

	var resp parseResponse
	if err := c.get(params, &resp); err != nil {
		return nil, err
	}

	if resp.Error != nil {
		return nil, fmt.Errorf("wiki API error: %s — %s", resp.Error.Code, resp.Error.Info)
	}

	return &ParsedPage{
		Title:    resp.Parse.Title,
		PageID:   resp.Parse.PageID,
		HTML:     resp.Parse.Text.Content,
		Sections: resp.Parse.Sections,
	}, nil
}

// FindSectionIndex searches the section list for a section matching the given name.
// Returns -1 if not found.
func FindSectionIndex(sections []Section, name string) int {
	for _, s := range sections {
		if s.Line == name {
			idx, err := strconv.Atoi(s.Index)
			if err != nil {
				continue
			}
			return idx
		}
	}
	return -1
}