基本能力编写完成

internal/stats/calculator.go

@@ -0,0 +1,175 @@
+package stats
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/gitcodestatic/gitcodestatic/internal/logger"
+	"github.com/gitcodestatic/gitcodestatic/internal/models"
+)
+
+// Calculator 统计计算器
+type Calculator struct {
+	gitPath string
+}
+
+// NewCalculator 创建统计计算器
+func NewCalculator(gitPath string) *Calculator {
+	if gitPath == "" {
+		gitPath = "git"
+	}
+	return &Calculator{gitPath: gitPath}
+}
+
+// Calculate 计算统计数据
+func (c *Calculator) Calculate(ctx context.Context, localPath, branch string, constraint *models.StatsConstraint) (*models.Statistics, error) {
+	// 构建git log命令
+	args := []string{
+		"-C", localPath,
+		"log",
+		"--no-merges",
+		"--numstat",
+		"--pretty=format:COMMIT:%H|AUTHOR:%an|EMAIL:%ae|DATE:%ai",
+	}
+
+	// 添加约束条件
+	if constraint != nil {
+		if constraint.Type == models.ConstraintTypeDateRange {
+			if constraint.From != "" {
+				args = append(args, "--since="+constraint.From)
+			}
+			if constraint.To != "" {
+				args = append(args, "--until="+constraint.To)
+			}
+		} else if constraint.Type == models.ConstraintTypeCommitLimit {
+			args = append(args, "-n", strconv.Itoa(constraint.Limit))
+		}
+	}
+
+	args = append(args, branch)
+
+	logger.Logger.Debug().
+		Str("local_path", localPath).
+		Str("branch", branch).
+		Interface("constraint", constraint).
+		Msg("running git log")
+
+	cmd := exec.CommandContext(ctx, c.gitPath, args...)
+	output, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("failed to run git log: %w", err)
+	}
+
+	// 解析输出
+	stats, err := c.parseGitLog(string(output))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse git log: %w", err)
+	}
+
+	// 填充摘要信息
+	stats.Summary.TotalContributors = len(stats.ByContributor)
+	if constraint != nil {
+		if constraint.Type == models.ConstraintTypeDateRange {
+			stats.Summary.DateRange = &models.DateRange{
+				From: constraint.From,
+				To:   constraint.To,
+			}
+		} else if constraint.Type == models.ConstraintTypeCommitLimit {
+			stats.Summary.CommitLimit = &constraint.Limit
+		}
+	}
+
+	return stats, nil
+}
+
+// parseGitLog 解析git log输出
+func (c *Calculator) parseGitLog(output string) (*models.Statistics, error) {
+	stats := &models.Statistics{
+		Summary:       models.StatsSummary{},
+		ByContributor: make([]models.ContributorStats, 0),
+	}
+
+	contributors := make(map[string]*models.ContributorStats)
+	
+	var currentAuthor, currentEmail string
+	commitCount := 0
+
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	commitPattern := regexp.MustCompile(`^COMMIT:(.+?)\|AUTHOR:(.+?)\|EMAIL:(.+?)\|DATE:(.+)$`)
+	numstatPattern := regexp.MustCompile(`^(\d+|-)\s+(\d+|-)\s+(.+)$`)
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		
+		if line == "" {
+			continue
+		}
+
+		// 匹配提交行
+		if matches := commitPattern.FindStringSubmatch(line); matches != nil {
+			currentAuthor = matches[2]
+			currentEmail = matches[3]
+			commitCount++
+
+			// 初始化贡献者统计
+			if _, ok := contributors[currentEmail]; !ok {
+				contributors[currentEmail] = &models.ContributorStats{
+					Author: currentAuthor,
+					Email:  currentEmail,
+				}
+			}
+			contributors[currentEmail].Commits++
+			continue
+		}
+
+		// 匹配文件变更行
+		if matches := numstatPattern.FindStringSubmatch(line); matches != nil && currentEmail != "" {
+			additionsStr := matches[1]
+			deletionsStr := matches[2]
+
+			// 处理二进制文件（显示为 -）
+			additions := 0
+			deletions := 0
+			
+			if additionsStr != "-" {
+				additions, _ = strconv.Atoi(additionsStr)
+			}
+			if deletionsStr != "-" {
+				deletions, _ = strconv.Atoi(deletionsStr)
+			}
+
+			contrib := contributors[currentEmail]
+			contrib.Additions += additions
+			contrib.Deletions += deletions
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error reading git log output: %w", err)
+	}
+
+	// 计算修改行数和净增加
+	for _, contrib := range contributors {
+		// 修改的定义：被替换的行数 = min(additions, deletions)
+		contrib.Modifications = min(contrib.Additions, contrib.Deletions)
+		contrib.NetAdditions = contrib.Additions - contrib.Deletions
+		stats.ByContributor = append(stats.ByContributor, *contrib)
+	}
+
+	stats.Summary.TotalCommits = commitCount
+
+	return stats, nil
+}
+
+// min 返回两个整数的最小值
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}